April 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] smb: client: refresh referral without acquiring refpath_lock" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0a05ad21d77a188d06481c36d6016805a881bcc0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040810-corporate-splinter-3a5f@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 0a05ad21d77a ("smb: client: refresh referral without acquiring refpath_lock") 062a7f0ff46e ("smb: client: guarantee refcounted children from parent session") d8392c203e84 ("smb3: show beginning time for per share stats") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0a05ad21d77a188d06481c36d6016805a881bcc0 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 22:44:07 -0300 Subject: [PATCH] smb: client: refresh referral without acquiring refpath_lock Avoid refreshing DFS referral with refpath_lock acquired as the I/O could block for a while due to a potentially disconnected or slow DFS root server and then making other threads - that use same @server and don't require a DFS root server - unable to make any progress. Cc: stable(a)vger.kernel.org # 6.4+ Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/dfs_cache.c b/fs/smb/client/dfs_cache.c index 0552a864ff08..11c8efecf7aa 100644 --- a/fs/smb/client/dfs_cache.c +++ b/fs/smb/client/dfs_cache.c @@ -1172,8 +1172,8 @@ static bool is_ses_good(struct cifs_ses *ses) return ret; } -/* Refresh dfs referral of tcon and mark it for reconnect if needed */ -static int __refresh_tcon(const char *path, struct cifs_ses *ses, bool force_refresh) +/* Refresh dfs referral of @ses and mark it for reconnect if needed */ +static void __refresh_ses_referral(struct cifs_ses *ses, bool force_refresh) { struct TCP_Server_Info *server = ses->server; DFS_CACHE_TGT_LIST(old_tl); @@ -1181,10 +1181,21 @@ static int __refresh_tcon(const char *path, struct cifs_ses *ses, bool force_ref bool needs_refresh = false; struct cache_entry *ce; unsigned int xid; + char *path = NULL; int rc = 0; xid = get_xid(); + mutex_lock(&server->refpath_lock); + if (server->leaf_fullpath) { + path = kstrdup(server->leaf_fullpath + 1, GFP_ATOMIC); + if (!path) + rc = -ENOMEM; + } + mutex_unlock(&server->refpath_lock); + if (!path) + goto out; + down_read(&htable_rw_lock); ce = lookup_cache_entry(path); needs_refresh = force_refresh || IS_ERR(ce) || cache_entry_expired(ce); @@ -1218,19 +1229,17 @@ static int __refresh_tcon(const char *path, struct cifs_ses *ses, bool force_ref free_xid(xid); dfs_cache_free_tgts(&old_tl); dfs_cache_free_tgts(&new_tl); - return rc; + kfree(path); } -static int refresh_tcon(struct cifs_tcon *tcon, bool force_refresh) +static inline void refresh_ses_referral(struct cifs_ses *ses) { - struct TCP_Server_Info *server = tcon->ses->server; - struct cifs_ses *ses = tcon->ses; + __refresh_ses_referral(ses, false); +} - mutex_lock(&server->refpath_lock); - if (server->leaf_fullpath) - __refresh_tcon(server->leaf_fullpath + 1, ses, force_refresh); - mutex_unlock(&server->refpath_lock); - return 0; +static inline void force_refresh_ses_referral(struct cifs_ses *ses) +{ + __refresh_ses_referral(ses, true); } /** @@ -1271,25 +1280,20 @@ int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb) */ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; - return refresh_tcon(tcon, true); + force_refresh_ses_referral(tcon->ses); + return 0; } /* Refresh all DFS referrals related to DFS tcon */ void dfs_cache_refresh(struct work_struct *work) { - struct TCP_Server_Info *server; struct cifs_tcon *tcon; struct cifs_ses *ses; tcon = container_of(work, struct cifs_tcon, dfs_cache_work.work); - for (ses = tcon->ses; ses; ses = ses->dfs_root_ses) { - server = ses->server; - mutex_lock(&server->refpath_lock); - if (server->leaf_fullpath) - __refresh_tcon(server->leaf_fullpath + 1, ses, false); - mutex_unlock(&server->refpath_lock); - } + for (ses = tcon->ses; ses; ses = ses->dfs_root_ses) + refresh_ses_referral(ses); queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work, atomic_read(&dfs_cache_ttl) * HZ);

9 months

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FAILED: patch "[PATCH] smb: client: guarantee refcounted children from parent" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 062a7f0ff46eb57aff526897bd2bebfdb1d3046a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040857-earthworm-untimely-552b@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 062a7f0ff46e ("smb: client: guarantee refcounted children from parent session") d8392c203e84 ("smb3: show beginning time for per share stats") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 062a7f0ff46eb57aff526897bd2bebfdb1d3046a Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 22:37:42 -0500 Subject: [PATCH] smb: client: guarantee refcounted children from parent session Avoid potential use-after-free bugs when walking DFS referrals, mounting and performing DFS failover by ensuring that all children from parent @tcon->ses are also refcounted. They're all needed across the entire DFS mount. Get rid of @tcon->dfs_ses_list while we're at it, too. Cc: stable(a)vger.kernel.org # 6.4+ Reported-by: kernel test robot <lkp(a)intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202404021527.ZlRkIxgv-lkp@intel.com/ Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index 7ed9d05f6890..286afbe346be 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -1281,7 +1281,6 @@ struct cifs_tcon { struct cached_fids *cfids; /* BB add field for back pointer to sb struct(s)? */ #ifdef CONFIG_CIFS_DFS_UPCALL - struct list_head dfs_ses_list; struct delayed_work dfs_cache_work; #endif struct delayed_work query_interfaces; /* query interfaces workqueue job */ @@ -1804,7 +1803,6 @@ struct cifs_mount_ctx { struct TCP_Server_Info *server; struct cifs_ses *ses; struct cifs_tcon *tcon; - struct list_head dfs_ses_list; }; static inline void __free_dfs_info_param(struct dfs_info3_param *param) diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h index 0723e1b57256..8e0a348f1f66 100644 --- a/fs/smb/client/cifsproto.h +++ b/fs/smb/client/cifsproto.h @@ -725,31 +725,31 @@ struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon); void cifs_put_tcon_super(struct super_block *sb); int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry); -/* Put references of @ses and @ses->dfs_root_ses */ +/* Put references of @ses and its children */ static inline void cifs_put_smb_ses(struct cifs_ses *ses) { - struct cifs_ses *rses = ses->dfs_root_ses; + struct cifs_ses *next; - __cifs_put_smb_ses(ses); - if (rses) - __cifs_put_smb_ses(rses); + do { + next = ses->dfs_root_ses; + __cifs_put_smb_ses(ses); + } while ((ses = next)); } -/* Get an active reference of @ses and @ses->dfs_root_ses. +/* Get an active reference of @ses and its children. * * NOTE: make sure to call this function when incrementing reference count of * @ses to ensure that any DFS root session attached to it (@ses->dfs_root_ses) * will also get its reference count incremented. * - * cifs_put_smb_ses() will put both references, so call it when you're done. + * cifs_put_smb_ses() will put all references, so call it when you're done. */ static inline void cifs_smb_ses_inc_refcount(struct cifs_ses *ses) { lockdep_assert_held(&cifs_tcp_ses_lock); - ses->ses_count++; - if (ses->dfs_root_ses) - ses->dfs_root_ses->ses_count++; + for (; ses; ses = ses->dfs_root_ses) + ses->ses_count++; } static inline bool dfs_src_pathname_equal(const char *s1, const char *s2) diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index ee29bc57300c..38b75cfa06e3 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -1866,6 +1866,9 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx) ctx->sectype != ses->sectype) return 0; + if (ctx->dfs_root_ses != ses->dfs_root_ses) + return 0; + /* * If an existing session is limited to less channels than * requested, it should not be reused @@ -2358,9 +2361,9 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) * need to lock before changing something in the session. */ spin_lock(&cifs_tcp_ses_lock); + if (ctx->dfs_root_ses) + cifs_smb_ses_inc_refcount(ctx->dfs_root_ses); ses->dfs_root_ses = ctx->dfs_root_ses; - if (ses->dfs_root_ses) - ses->dfs_root_ses->ses_count++; list_add(&ses->smb_ses_list, &server->smb_ses_list); spin_unlock(&cifs_tcp_ses_lock); @@ -3311,6 +3314,9 @@ void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx) cifs_put_smb_ses(mnt_ctx->ses); else if (mnt_ctx->server) cifs_put_tcp_session(mnt_ctx->server, 0); + mnt_ctx->ses = NULL; + mnt_ctx->tcon = NULL; + mnt_ctx->server = NULL; mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; free_xid(mnt_ctx->xid); } @@ -3589,8 +3595,6 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) bool isdfs; int rc; - INIT_LIST_HEAD(&mnt_ctx.dfs_ses_list); - rc = dfs_mount_share(&mnt_ctx, &isdfs); if (rc) goto error; @@ -3621,7 +3625,6 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) return rc; error: - dfs_put_root_smb_sessions(&mnt_ctx.dfs_ses_list); cifs_mount_put_conns(&mnt_ctx); return rc; } @@ -3636,6 +3639,18 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) goto error; rc = cifs_mount_get_tcon(&mnt_ctx); + if (!rc) { + /* + * Prevent superblock from being created with any missing + * connections. + */ + if (WARN_ON(!mnt_ctx.server)) + rc = -EHOSTDOWN; + else if (WARN_ON(!mnt_ctx.ses)) + rc = -EACCES; + else if (WARN_ON(!mnt_ctx.tcon)) + rc = -ENOENT; + } if (rc) goto error; diff --git a/fs/smb/client/dfs.c b/fs/smb/client/dfs.c index 449c59830039..3ec965547e3d 100644 --- a/fs/smb/client/dfs.c +++ b/fs/smb/client/dfs.c @@ -66,33 +66,20 @@ static int get_session(struct cifs_mount_ctx *mnt_ctx, const char *full_path) } /* - * Track individual DFS referral servers used by new DFS mount. - * - * On success, their lifetime will be shared by final tcon (dfs_ses_list). - * Otherwise, they will be put by dfs_put_root_smb_sessions() in cifs_mount(). + * Get an active reference of @ses so that next call to cifs_put_tcon() won't + * release it as any new DFS referrals must go through its IPC tcon. */ -static int add_root_smb_session(struct cifs_mount_ctx *mnt_ctx) +static void add_root_smb_session(struct cifs_mount_ctx *mnt_ctx) { struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; - struct dfs_root_ses *root_ses; struct cifs_ses *ses = mnt_ctx->ses; if (ses) { - root_ses = kmalloc(sizeof(*root_ses), GFP_KERNEL); - if (!root_ses) - return -ENOMEM; - - INIT_LIST_HEAD(&root_ses->list); - spin_lock(&cifs_tcp_ses_lock); cifs_smb_ses_inc_refcount(ses); spin_unlock(&cifs_tcp_ses_lock); - root_ses->ses = ses; - list_add_tail(&root_ses->list, &mnt_ctx->dfs_ses_list); } - /* Select new DFS referral server so that new referrals go through it */ ctx->dfs_root_ses = ses; - return 0; } static inline int parse_dfs_target(struct smb3_fs_context *ctx, @@ -185,11 +172,8 @@ static int __dfs_referral_walk(struct cifs_mount_ctx *mnt_ctx, continue; } - if (is_refsrv) { - rc = add_root_smb_session(mnt_ctx); - if (rc) - goto out; - } + if (is_refsrv) + add_root_smb_session(mnt_ctx); rc = ref_walk_advance(rw); if (!rc) { @@ -232,6 +216,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; struct cifs_tcon *tcon; char *origin_fullpath; + bool new_tcon = true; int rc; origin_fullpath = dfs_get_path(cifs_sb, ctx->source); @@ -239,6 +224,18 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) return PTR_ERR(origin_fullpath); rc = dfs_referral_walk(mnt_ctx); + if (!rc) { + /* + * Prevent superblock from being created with any missing + * connections. + */ + if (WARN_ON(!mnt_ctx->server)) + rc = -EHOSTDOWN; + else if (WARN_ON(!mnt_ctx->ses)) + rc = -EACCES; + else if (WARN_ON(!mnt_ctx->tcon)) + rc = -ENOENT; + } if (rc) goto out; @@ -247,15 +244,14 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) if (!tcon->origin_fullpath) { tcon->origin_fullpath = origin_fullpath; origin_fullpath = NULL; + } else { + new_tcon = false; } spin_unlock(&tcon->tc_lock); - if (list_empty(&tcon->dfs_ses_list)) { - list_replace_init(&mnt_ctx->dfs_ses_list, &tcon->dfs_ses_list); + if (new_tcon) { queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work, dfs_cache_get_ttl() * HZ); - } else { - dfs_put_root_smb_sessions(&mnt_ctx->dfs_ses_list); } out: @@ -298,7 +294,6 @@ int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs) if (rc) return rc; - ctx->dfs_root_ses = mnt_ctx->ses; /* * If called with 'nodfs' mount option, then skip DFS resolving. Otherwise unconditionally * try to get an DFS referral (even cached) to determine whether it is an DFS mount. @@ -324,7 +319,9 @@ int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs) *isdfs = true; add_root_smb_session(mnt_ctx); - return __dfs_mount_share(mnt_ctx); + rc = __dfs_mount_share(mnt_ctx); + dfs_put_root_smb_sessions(mnt_ctx); + return rc; } /* Update dfs referral path of superblock */ diff --git a/fs/smb/client/dfs.h b/fs/smb/client/dfs.h index 875ab7ae57fc..e5c4dcf83750 100644 --- a/fs/smb/client/dfs.h +++ b/fs/smb/client/dfs.h @@ -7,7 +7,9 @@ #define _CIFS_DFS_H #include "cifsglob.h" +#include "cifsproto.h" #include "fs_context.h" +#include "dfs_cache.h" #include "cifs_unicode.h" #include <linux/namei.h> @@ -114,11 +116,6 @@ static inline void ref_walk_set_tgt_hint(struct dfs_ref_walk *rw) ref_walk_tit(rw)); } -struct dfs_root_ses { - struct list_head list; - struct cifs_ses *ses; -}; - int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_param *ref, struct smb3_fs_context *ctx); int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs); @@ -133,20 +130,32 @@ static inline int dfs_get_referral(struct cifs_mount_ctx *mnt_ctx, const char *p { struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct cifs_ses *rses = ctx->dfs_root_ses ?: mnt_ctx->ses; - return dfs_cache_find(mnt_ctx->xid, ctx->dfs_root_ses, cifs_sb->local_nls, + return dfs_cache_find(mnt_ctx->xid, rses, cifs_sb->local_nls, cifs_remap(cifs_sb), path, ref, tl); } -static inline void dfs_put_root_smb_sessions(struct list_head *head) +/* + * cifs_get_smb_ses() already guarantees an active reference of + * @ses->dfs_root_ses when a new session is created, so we need to put extra + * references of all DFS root sessions that were used across the mount process + * in dfs_mount_share(). + */ +static inline void dfs_put_root_smb_sessions(struct cifs_mount_ctx *mnt_ctx) { - struct dfs_root_ses *root, *tmp; + const struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + struct cifs_ses *ses = ctx->dfs_root_ses; + struct cifs_ses *cur; - list_for_each_entry_safe(root, tmp, head, list) { - list_del_init(&root->list); - cifs_put_smb_ses(root->ses); - kfree(root); + if (!ses) + return; + + for (cur = ses; cur; cur = cur->dfs_root_ses) { + if (cur->dfs_root_ses) + cifs_put_smb_ses(cur->dfs_root_ses); } + cifs_put_smb_ses(ses); } #endif /* _CIFS_DFS_H */ diff --git a/fs/smb/client/dfs_cache.c b/fs/smb/client/dfs_cache.c index 508d831fabe3..0552a864ff08 100644 --- a/fs/smb/client/dfs_cache.c +++ b/fs/smb/client/dfs_cache.c @@ -1278,21 +1278,12 @@ int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb) void dfs_cache_refresh(struct work_struct *work) { struct TCP_Server_Info *server; - struct dfs_root_ses *rses; struct cifs_tcon *tcon; struct cifs_ses *ses; tcon = container_of(work, struct cifs_tcon, dfs_cache_work.work); - ses = tcon->ses; - server = ses->server; - mutex_lock(&server->refpath_lock); - if (server->leaf_fullpath) - __refresh_tcon(server->leaf_fullpath + 1, ses, false); - mutex_unlock(&server->refpath_lock); - - list_for_each_entry(rses, &tcon->dfs_ses_list, list) { - ses = rses->ses; + for (ses = tcon->ses; ses; ses = ses->dfs_root_ses) { server = ses->server; mutex_lock(&server->refpath_lock); if (server->leaf_fullpath) diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c index c3771fc81328..1ea22b3955a2 100644 --- a/fs/smb/client/misc.c +++ b/fs/smb/client/misc.c @@ -138,9 +138,6 @@ tcon_info_alloc(bool dir_leases_enabled) atomic_set(&ret_buf->num_local_opens, 0); atomic_set(&ret_buf->num_remote_opens, 0); ret_buf->stats_from_time = ktime_get_real_seconds(); -#ifdef CONFIG_CIFS_DFS_UPCALL - INIT_LIST_HEAD(&ret_buf->dfs_ses_list); -#endif return ret_buf; } @@ -156,9 +153,6 @@ tconInfoFree(struct cifs_tcon *tcon) atomic_dec(&tconInfoAllocCount); kfree(tcon->nativeFileSystem); kfree_sensitive(tcon->password); -#ifdef CONFIG_CIFS_DFS_UPCALL - dfs_put_root_smb_sessions(&tcon->dfs_ses_list); -#endif kfree(tcon->origin_fullpath); kfree(tcon); }

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FAILED: patch "[PATCH] smb: client: fix UAF in smb2_reconnect_server()" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 24a9799aa8efecd0eb55a75e35f9d8e6400063aa # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040843-empathic-duller-2cb9@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()") 7257bcf3bdc7 ("cifs: cifs_chan_is_iface_active should be called with chan_lock held") 27e1fd343f80 ("cifs: after disabling multichannel, mark tcon for reconnect") fa1d0508bdd4 ("cifs: account for primary channel in the interface list") a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") c37ed2d7d098 ("smb: client: remove extra @chan_count check in __cifs_put_smb_ses()") ff7d80a9f271 ("cifs: fix session state transition to avoid use-after-free issue") 38c8a9a52082 ("smb: move client and server files to common directory fs/smb") 943fb67b0902 ("cifs: missing lock when updating session status") bc962159e8e3 ("cifs: avoid race conditions with parallel reconnects") 1bcd548d935a ("cifs: prevent data race in cifs_reconnect_tcon()") e77978de4765 ("cifs: update ip_addr for ses only for primary chan setup") 3c0070f54b31 ("cifs: prevent data race in smb2_reconnect()") 05844bd661d9 ("cifs: print last update time for interface list") 25cf01b7c920 ("cifs: set correct status of tcon ipc when reconnecting") abdb1742a312 ("cifs: get rid of mount options string parsing") 9fd29a5bae6e ("cifs: use fs_context for automounts") f391d6ee002e ("cifs: Use after free in debug code") 68e14569d7e5 ("smb3: add dynamic trace points for tree disconnect") 13609a8b3ac6 ("cifs: move from strlcpy with unused retval to strscpy") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 24a9799aa8efecd0eb55a75e35f9d8e6400063aa Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 14:13:10 -0300 Subject: [PATCH] smb: client: fix UAF in smb2_reconnect_server() The UAF bug is due to smb2_reconnect_server() accessing a session that is already being teared down by another thread that is executing __cifs_put_smb_ses(). This can happen when (a) the client has connection to the server but no session or (b) another thread ends up setting @ses->ses_status again to something different than SES_EXITING. To fix this, we need to make sure to unconditionally set @ses->ses_status to SES_EXITING and prevent any other threads from setting a new status while we're still tearing it down. The following can be reproduced by adding some delay to right after the ipc is freed in __cifs_put_smb_ses() - which will give smb2_reconnect_server() worker a chance to run and then accessing @ses->ipc: kinit ... mount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10 [disconnect srv] ls /mnt/1 &>/dev/null sleep 30 kdestroy [reconnect srv] sleep 10 umount /mnt/1 ... CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Workqueue: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0 Code: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75 7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8 RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83 RAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800 RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000 R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000 FS: 0000000000000000(0000) GS:ffff888157c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x36/0x90 ? exc_general_protection+0x1c1/0x3f0 ? asm_exc_general_protection+0x26/0x30 ? __list_del_entry_valid_or_report+0x33/0xf0 __cifs_put_smb_ses+0x1ae/0x500 [cifs] smb2_reconnect_server+0x4ed/0x710 [cifs] process_one_work+0x205/0x6b0 worker_thread+0x191/0x360 ? __pfx_worker_thread+0x10/0x10 kthread+0xe2/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 9b85b5341822..ee29bc57300c 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -232,7 +232,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server, spin_lock(&cifs_tcp_ses_lock); list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) { - /* check if iface is still active */ + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } + spin_unlock(&ses->ses_lock); + spin_lock(&ses->chan_lock); if (cifs_ses_get_chan_index(ses, server) == CIFS_INVAL_CHAN_INDEX) { @@ -1963,31 +1969,6 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) return rc; } -/** - * cifs_free_ipc - helper to release the session IPC tcon - * @ses: smb session to unmount the IPC from - * - * Needs to be called everytime a session is destroyed. - * - * On session close, the IPC is closed and the server must release all tcons of the session. - * No need to send a tree disconnect here. - * - * Besides, it will make the server to not close durable and resilient files on session close, as - * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request. - */ -static int -cifs_free_ipc(struct cifs_ses *ses) -{ - struct cifs_tcon *tcon = ses->tcon_ipc; - - if (tcon == NULL) - return 0; - - tconInfoFree(tcon); - ses->tcon_ipc = NULL; - return 0; -} - static struct cifs_ses * cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { @@ -2019,48 +2000,52 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) void __cifs_put_smb_ses(struct cifs_ses *ses) { struct TCP_Server_Info *server = ses->server; + struct cifs_tcon *tcon; unsigned int xid; size_t i; + bool do_logoff; int rc; - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING) { - spin_unlock(&ses->ses_lock); - return; - } - spin_unlock(&ses->ses_lock); - - cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); - cifs_dbg(FYI, - "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE"); - spin_lock(&cifs_tcp_ses_lock); - if (--ses->ses_count > 0) { + spin_lock(&ses->ses_lock); + cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n", + __func__, ses->Suid, ses->ses_count, ses->ses_status, + ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none"); + if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) { + spin_unlock(&ses->ses_lock); spin_unlock(&cifs_tcp_ses_lock); return; } - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_GOOD) - ses->ses_status = SES_EXITING; - spin_unlock(&ses->ses_lock); - spin_unlock(&cifs_tcp_ses_lock); - /* ses_count can never go negative */ WARN_ON(ses->ses_count < 0); - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING && server->ops->logoff) { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); + spin_lock(&ses->chan_lock); + cifs_chan_clear_need_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + + do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff; + ses->ses_status = SES_EXITING; + tcon = ses->tcon_ipc; + ses->tcon_ipc = NULL; + spin_unlock(&ses->ses_lock); + spin_unlock(&cifs_tcp_ses_lock); + + /* + * On session close, the IPC is closed and the server must release all + * tcons of the session. No need to send a tree disconnect here. + * + * Besides, it will make the server to not close durable and resilient + * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an + * SMB2 LOGOFF Request. + */ + tconInfoFree(tcon); + if (do_logoff) { xid = get_xid(); rc = server->ops->logoff(xid, ses); if (rc) cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n", __func__, rc); _free_xid(xid); - } else { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); } spin_lock(&cifs_tcp_ses_lock);

9 months

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FAILED: patch "[PATCH] smb: client: fix UAF in smb2_reconnect_server()" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 24a9799aa8efecd0eb55a75e35f9d8e6400063aa # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040841-scarcity-subarctic-4f20@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()") 7257bcf3bdc7 ("cifs: cifs_chan_is_iface_active should be called with chan_lock held") 27e1fd343f80 ("cifs: after disabling multichannel, mark tcon for reconnect") fa1d0508bdd4 ("cifs: account for primary channel in the interface list") a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") c37ed2d7d098 ("smb: client: remove extra @chan_count check in __cifs_put_smb_ses()") ff7d80a9f271 ("cifs: fix session state transition to avoid use-after-free issue") 38c8a9a52082 ("smb: move client and server files to common directory fs/smb") 943fb67b0902 ("cifs: missing lock when updating session status") bc962159e8e3 ("cifs: avoid race conditions with parallel reconnects") 1bcd548d935a ("cifs: prevent data race in cifs_reconnect_tcon()") e77978de4765 ("cifs: update ip_addr for ses only for primary chan setup") 3c0070f54b31 ("cifs: prevent data race in smb2_reconnect()") 05844bd661d9 ("cifs: print last update time for interface list") 25cf01b7c920 ("cifs: set correct status of tcon ipc when reconnecting") abdb1742a312 ("cifs: get rid of mount options string parsing") 9fd29a5bae6e ("cifs: use fs_context for automounts") f391d6ee002e ("cifs: Use after free in debug code") 68e14569d7e5 ("smb3: add dynamic trace points for tree disconnect") 13609a8b3ac6 ("cifs: move from strlcpy with unused retval to strscpy") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 24a9799aa8efecd0eb55a75e35f9d8e6400063aa Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 14:13:10 -0300 Subject: [PATCH] smb: client: fix UAF in smb2_reconnect_server() The UAF bug is due to smb2_reconnect_server() accessing a session that is already being teared down by another thread that is executing __cifs_put_smb_ses(). This can happen when (a) the client has connection to the server but no session or (b) another thread ends up setting @ses->ses_status again to something different than SES_EXITING. To fix this, we need to make sure to unconditionally set @ses->ses_status to SES_EXITING and prevent any other threads from setting a new status while we're still tearing it down. The following can be reproduced by adding some delay to right after the ipc is freed in __cifs_put_smb_ses() - which will give smb2_reconnect_server() worker a chance to run and then accessing @ses->ipc: kinit ... mount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10 [disconnect srv] ls /mnt/1 &>/dev/null sleep 30 kdestroy [reconnect srv] sleep 10 umount /mnt/1 ... CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Workqueue: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0 Code: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75 7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8 RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83 RAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800 RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000 R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000 FS: 0000000000000000(0000) GS:ffff888157c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x36/0x90 ? exc_general_protection+0x1c1/0x3f0 ? asm_exc_general_protection+0x26/0x30 ? __list_del_entry_valid_or_report+0x33/0xf0 __cifs_put_smb_ses+0x1ae/0x500 [cifs] smb2_reconnect_server+0x4ed/0x710 [cifs] process_one_work+0x205/0x6b0 worker_thread+0x191/0x360 ? __pfx_worker_thread+0x10/0x10 kthread+0xe2/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 9b85b5341822..ee29bc57300c 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -232,7 +232,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server, spin_lock(&cifs_tcp_ses_lock); list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) { - /* check if iface is still active */ + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } + spin_unlock(&ses->ses_lock); + spin_lock(&ses->chan_lock); if (cifs_ses_get_chan_index(ses, server) == CIFS_INVAL_CHAN_INDEX) { @@ -1963,31 +1969,6 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) return rc; } -/** - * cifs_free_ipc - helper to release the session IPC tcon - * @ses: smb session to unmount the IPC from - * - * Needs to be called everytime a session is destroyed. - * - * On session close, the IPC is closed and the server must release all tcons of the session. - * No need to send a tree disconnect here. - * - * Besides, it will make the server to not close durable and resilient files on session close, as - * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request. - */ -static int -cifs_free_ipc(struct cifs_ses *ses) -{ - struct cifs_tcon *tcon = ses->tcon_ipc; - - if (tcon == NULL) - return 0; - - tconInfoFree(tcon); - ses->tcon_ipc = NULL; - return 0; -} - static struct cifs_ses * cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { @@ -2019,48 +2000,52 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) void __cifs_put_smb_ses(struct cifs_ses *ses) { struct TCP_Server_Info *server = ses->server; + struct cifs_tcon *tcon; unsigned int xid; size_t i; + bool do_logoff; int rc; - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING) { - spin_unlock(&ses->ses_lock); - return; - } - spin_unlock(&ses->ses_lock); - - cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); - cifs_dbg(FYI, - "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE"); - spin_lock(&cifs_tcp_ses_lock); - if (--ses->ses_count > 0) { + spin_lock(&ses->ses_lock); + cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n", + __func__, ses->Suid, ses->ses_count, ses->ses_status, + ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none"); + if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) { + spin_unlock(&ses->ses_lock); spin_unlock(&cifs_tcp_ses_lock); return; } - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_GOOD) - ses->ses_status = SES_EXITING; - spin_unlock(&ses->ses_lock); - spin_unlock(&cifs_tcp_ses_lock); - /* ses_count can never go negative */ WARN_ON(ses->ses_count < 0); - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING && server->ops->logoff) { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); + spin_lock(&ses->chan_lock); + cifs_chan_clear_need_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + + do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff; + ses->ses_status = SES_EXITING; + tcon = ses->tcon_ipc; + ses->tcon_ipc = NULL; + spin_unlock(&ses->ses_lock); + spin_unlock(&cifs_tcp_ses_lock); + + /* + * On session close, the IPC is closed and the server must release all + * tcons of the session. No need to send a tree disconnect here. + * + * Besides, it will make the server to not close durable and resilient + * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an + * SMB2 LOGOFF Request. + */ + tconInfoFree(tcon); + if (do_logoff) { xid = get_xid(); rc = server->ops->logoff(xid, ses); if (rc) cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n", __func__, rc); _free_xid(xid); - } else { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); } spin_lock(&cifs_tcp_ses_lock);

9 months

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FAILED: patch "[PATCH] smb: client: fix UAF in smb2_reconnect_server()" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 24a9799aa8efecd0eb55a75e35f9d8e6400063aa # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040839-drainage-uninvited-614e@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()") 7257bcf3bdc7 ("cifs: cifs_chan_is_iface_active should be called with chan_lock held") 27e1fd343f80 ("cifs: after disabling multichannel, mark tcon for reconnect") fa1d0508bdd4 ("cifs: account for primary channel in the interface list") a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") c37ed2d7d098 ("smb: client: remove extra @chan_count check in __cifs_put_smb_ses()") ff7d80a9f271 ("cifs: fix session state transition to avoid use-after-free issue") 38c8a9a52082 ("smb: move client and server files to common directory fs/smb") 943fb67b0902 ("cifs: missing lock when updating session status") bc962159e8e3 ("cifs: avoid race conditions with parallel reconnects") 1bcd548d935a ("cifs: prevent data race in cifs_reconnect_tcon()") e77978de4765 ("cifs: update ip_addr for ses only for primary chan setup") 3c0070f54b31 ("cifs: prevent data race in smb2_reconnect()") 05844bd661d9 ("cifs: print last update time for interface list") 25cf01b7c920 ("cifs: set correct status of tcon ipc when reconnecting") abdb1742a312 ("cifs: get rid of mount options string parsing") 9fd29a5bae6e ("cifs: use fs_context for automounts") f391d6ee002e ("cifs: Use after free in debug code") 68e14569d7e5 ("smb3: add dynamic trace points for tree disconnect") 13609a8b3ac6 ("cifs: move from strlcpy with unused retval to strscpy") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 24a9799aa8efecd0eb55a75e35f9d8e6400063aa Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 14:13:10 -0300 Subject: [PATCH] smb: client: fix UAF in smb2_reconnect_server() The UAF bug is due to smb2_reconnect_server() accessing a session that is already being teared down by another thread that is executing __cifs_put_smb_ses(). This can happen when (a) the client has connection to the server but no session or (b) another thread ends up setting @ses->ses_status again to something different than SES_EXITING. To fix this, we need to make sure to unconditionally set @ses->ses_status to SES_EXITING and prevent any other threads from setting a new status while we're still tearing it down. The following can be reproduced by adding some delay to right after the ipc is freed in __cifs_put_smb_ses() - which will give smb2_reconnect_server() worker a chance to run and then accessing @ses->ipc: kinit ... mount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10 [disconnect srv] ls /mnt/1 &>/dev/null sleep 30 kdestroy [reconnect srv] sleep 10 umount /mnt/1 ... CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Workqueue: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0 Code: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75 7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8 RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83 RAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800 RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000 R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000 FS: 0000000000000000(0000) GS:ffff888157c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x36/0x90 ? exc_general_protection+0x1c1/0x3f0 ? asm_exc_general_protection+0x26/0x30 ? __list_del_entry_valid_or_report+0x33/0xf0 __cifs_put_smb_ses+0x1ae/0x500 [cifs] smb2_reconnect_server+0x4ed/0x710 [cifs] process_one_work+0x205/0x6b0 worker_thread+0x191/0x360 ? __pfx_worker_thread+0x10/0x10 kthread+0xe2/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 9b85b5341822..ee29bc57300c 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -232,7 +232,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server, spin_lock(&cifs_tcp_ses_lock); list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) { - /* check if iface is still active */ + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } + spin_unlock(&ses->ses_lock); + spin_lock(&ses->chan_lock); if (cifs_ses_get_chan_index(ses, server) == CIFS_INVAL_CHAN_INDEX) { @@ -1963,31 +1969,6 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) return rc; } -/** - * cifs_free_ipc - helper to release the session IPC tcon - * @ses: smb session to unmount the IPC from - * - * Needs to be called everytime a session is destroyed. - * - * On session close, the IPC is closed and the server must release all tcons of the session. - * No need to send a tree disconnect here. - * - * Besides, it will make the server to not close durable and resilient files on session close, as - * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request. - */ -static int -cifs_free_ipc(struct cifs_ses *ses) -{ - struct cifs_tcon *tcon = ses->tcon_ipc; - - if (tcon == NULL) - return 0; - - tconInfoFree(tcon); - ses->tcon_ipc = NULL; - return 0; -} - static struct cifs_ses * cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { @@ -2019,48 +2000,52 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) void __cifs_put_smb_ses(struct cifs_ses *ses) { struct TCP_Server_Info *server = ses->server; + struct cifs_tcon *tcon; unsigned int xid; size_t i; + bool do_logoff; int rc; - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING) { - spin_unlock(&ses->ses_lock); - return; - } - spin_unlock(&ses->ses_lock); - - cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); - cifs_dbg(FYI, - "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE"); - spin_lock(&cifs_tcp_ses_lock); - if (--ses->ses_count > 0) { + spin_lock(&ses->ses_lock); + cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n", + __func__, ses->Suid, ses->ses_count, ses->ses_status, + ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none"); + if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) { + spin_unlock(&ses->ses_lock); spin_unlock(&cifs_tcp_ses_lock); return; } - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_GOOD) - ses->ses_status = SES_EXITING; - spin_unlock(&ses->ses_lock); - spin_unlock(&cifs_tcp_ses_lock); - /* ses_count can never go negative */ WARN_ON(ses->ses_count < 0); - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING && server->ops->logoff) { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); + spin_lock(&ses->chan_lock); + cifs_chan_clear_need_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + + do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff; + ses->ses_status = SES_EXITING; + tcon = ses->tcon_ipc; + ses->tcon_ipc = NULL; + spin_unlock(&ses->ses_lock); + spin_unlock(&cifs_tcp_ses_lock); + + /* + * On session close, the IPC is closed and the server must release all + * tcons of the session. No need to send a tree disconnect here. + * + * Besides, it will make the server to not close durable and resilient + * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an + * SMB2 LOGOFF Request. + */ + tconInfoFree(tcon); + if (do_logoff) { xid = get_xid(); rc = server->ops->logoff(xid, ses); if (rc) cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n", __func__, rc); _free_xid(xid); - } else { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); } spin_lock(&cifs_tcp_ses_lock);

9 months

1
0
0 0

FAILED: patch "[PATCH] smb: client: fix UAF in smb2_reconnect_server()" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 24a9799aa8efecd0eb55a75e35f9d8e6400063aa # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040837-alkaline-motor-f911@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()") 7257bcf3bdc7 ("cifs: cifs_chan_is_iface_active should be called with chan_lock held") 27e1fd343f80 ("cifs: after disabling multichannel, mark tcon for reconnect") fa1d0508bdd4 ("cifs: account for primary channel in the interface list") a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") c37ed2d7d098 ("smb: client: remove extra @chan_count check in __cifs_put_smb_ses()") ff7d80a9f271 ("cifs: fix session state transition to avoid use-after-free issue") 38c8a9a52082 ("smb: move client and server files to common directory fs/smb") 943fb67b0902 ("cifs: missing lock when updating session status") bc962159e8e3 ("cifs: avoid race conditions with parallel reconnects") 1bcd548d935a ("cifs: prevent data race in cifs_reconnect_tcon()") e77978de4765 ("cifs: update ip_addr for ses only for primary chan setup") 3c0070f54b31 ("cifs: prevent data race in smb2_reconnect()") 05844bd661d9 ("cifs: print last update time for interface list") 25cf01b7c920 ("cifs: set correct status of tcon ipc when reconnecting") abdb1742a312 ("cifs: get rid of mount options string parsing") 9fd29a5bae6e ("cifs: use fs_context for automounts") f391d6ee002e ("cifs: Use after free in debug code") 68e14569d7e5 ("smb3: add dynamic trace points for tree disconnect") 13609a8b3ac6 ("cifs: move from strlcpy with unused retval to strscpy") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 24a9799aa8efecd0eb55a75e35f9d8e6400063aa Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 14:13:10 -0300 Subject: [PATCH] smb: client: fix UAF in smb2_reconnect_server() The UAF bug is due to smb2_reconnect_server() accessing a session that is already being teared down by another thread that is executing __cifs_put_smb_ses(). This can happen when (a) the client has connection to the server but no session or (b) another thread ends up setting @ses->ses_status again to something different than SES_EXITING. To fix this, we need to make sure to unconditionally set @ses->ses_status to SES_EXITING and prevent any other threads from setting a new status while we're still tearing it down. The following can be reproduced by adding some delay to right after the ipc is freed in __cifs_put_smb_ses() - which will give smb2_reconnect_server() worker a chance to run and then accessing @ses->ipc: kinit ... mount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10 [disconnect srv] ls /mnt/1 &>/dev/null sleep 30 kdestroy [reconnect srv] sleep 10 umount /mnt/1 ... CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Workqueue: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0 Code: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75 7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8 RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83 RAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800 RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000 R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000 FS: 0000000000000000(0000) GS:ffff888157c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x36/0x90 ? exc_general_protection+0x1c1/0x3f0 ? asm_exc_general_protection+0x26/0x30 ? __list_del_entry_valid_or_report+0x33/0xf0 __cifs_put_smb_ses+0x1ae/0x500 [cifs] smb2_reconnect_server+0x4ed/0x710 [cifs] process_one_work+0x205/0x6b0 worker_thread+0x191/0x360 ? __pfx_worker_thread+0x10/0x10 kthread+0xe2/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 9b85b5341822..ee29bc57300c 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -232,7 +232,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server, spin_lock(&cifs_tcp_ses_lock); list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) { - /* check if iface is still active */ + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } + spin_unlock(&ses->ses_lock); + spin_lock(&ses->chan_lock); if (cifs_ses_get_chan_index(ses, server) == CIFS_INVAL_CHAN_INDEX) { @@ -1963,31 +1969,6 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) return rc; } -/** - * cifs_free_ipc - helper to release the session IPC tcon - * @ses: smb session to unmount the IPC from - * - * Needs to be called everytime a session is destroyed. - * - * On session close, the IPC is closed and the server must release all tcons of the session. - * No need to send a tree disconnect here. - * - * Besides, it will make the server to not close durable and resilient files on session close, as - * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request. - */ -static int -cifs_free_ipc(struct cifs_ses *ses) -{ - struct cifs_tcon *tcon = ses->tcon_ipc; - - if (tcon == NULL) - return 0; - - tconInfoFree(tcon); - ses->tcon_ipc = NULL; - return 0; -} - static struct cifs_ses * cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { @@ -2019,48 +2000,52 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) void __cifs_put_smb_ses(struct cifs_ses *ses) { struct TCP_Server_Info *server = ses->server; + struct cifs_tcon *tcon; unsigned int xid; size_t i; + bool do_logoff; int rc; - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING) { - spin_unlock(&ses->ses_lock); - return; - } - spin_unlock(&ses->ses_lock); - - cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); - cifs_dbg(FYI, - "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE"); - spin_lock(&cifs_tcp_ses_lock); - if (--ses->ses_count > 0) { + spin_lock(&ses->ses_lock); + cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n", + __func__, ses->Suid, ses->ses_count, ses->ses_status, + ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none"); + if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) { + spin_unlock(&ses->ses_lock); spin_unlock(&cifs_tcp_ses_lock); return; } - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_GOOD) - ses->ses_status = SES_EXITING; - spin_unlock(&ses->ses_lock); - spin_unlock(&cifs_tcp_ses_lock); - /* ses_count can never go negative */ WARN_ON(ses->ses_count < 0); - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING && server->ops->logoff) { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); + spin_lock(&ses->chan_lock); + cifs_chan_clear_need_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + + do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff; + ses->ses_status = SES_EXITING; + tcon = ses->tcon_ipc; + ses->tcon_ipc = NULL; + spin_unlock(&ses->ses_lock); + spin_unlock(&cifs_tcp_ses_lock); + + /* + * On session close, the IPC is closed and the server must release all + * tcons of the session. No need to send a tree disconnect here. + * + * Besides, it will make the server to not close durable and resilient + * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an + * SMB2 LOGOFF Request. + */ + tconInfoFree(tcon); + if (do_logoff) { xid = get_xid(); rc = server->ops->logoff(xid, ses); if (rc) cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n", __func__, rc); _free_xid(xid); - } else { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); } spin_lock(&cifs_tcp_ses_lock);

9 months

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0 0

FAILED: patch "[PATCH] smb: client: fix UAF in smb2_reconnect_server()" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 24a9799aa8efecd0eb55a75e35f9d8e6400063aa # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040832-episode-phrasing-9e1a@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()") 7257bcf3bdc7 ("cifs: cifs_chan_is_iface_active should be called with chan_lock held") 27e1fd343f80 ("cifs: after disabling multichannel, mark tcon for reconnect") fa1d0508bdd4 ("cifs: account for primary channel in the interface list") a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") c37ed2d7d098 ("smb: client: remove extra @chan_count check in __cifs_put_smb_ses()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 24a9799aa8efecd0eb55a75e35f9d8e6400063aa Mon Sep 17 00:00:00 2001 From: Paulo Alcantara <pc(a)manguebit.com> Date: Mon, 1 Apr 2024 14:13:10 -0300 Subject: [PATCH] smb: client: fix UAF in smb2_reconnect_server() The UAF bug is due to smb2_reconnect_server() accessing a session that is already being teared down by another thread that is executing __cifs_put_smb_ses(). This can happen when (a) the client has connection to the server but no session or (b) another thread ends up setting @ses->ses_status again to something different than SES_EXITING. To fix this, we need to make sure to unconditionally set @ses->ses_status to SES_EXITING and prevent any other threads from setting a new status while we're still tearing it down. The following can be reproduced by adding some delay to right after the ipc is freed in __cifs_put_smb_ses() - which will give smb2_reconnect_server() worker a chance to run and then accessing @ses->ipc: kinit ... mount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10 [disconnect srv] ls /mnt/1 &>/dev/null sleep 30 kdestroy [reconnect srv] sleep 10 umount /mnt/1 ... CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed CIFS: VFS: \\srv Send error in SessSetup = -126 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Workqueue: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0 Code: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75 7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8 RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83 RAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800 RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000 R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000 FS: 0000000000000000(0000) GS:ffff888157c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x36/0x90 ? exc_general_protection+0x1c1/0x3f0 ? asm_exc_general_protection+0x26/0x30 ? __list_del_entry_valid_or_report+0x33/0xf0 __cifs_put_smb_ses+0x1ae/0x500 [cifs] smb2_reconnect_server+0x4ed/0x710 [cifs] process_one_work+0x205/0x6b0 worker_thread+0x191/0x360 ? __pfx_worker_thread+0x10/0x10 kthread+0xe2/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 9b85b5341822..ee29bc57300c 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -232,7 +232,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server, spin_lock(&cifs_tcp_ses_lock); list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) { - /* check if iface is still active */ + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } + spin_unlock(&ses->ses_lock); + spin_lock(&ses->chan_lock); if (cifs_ses_get_chan_index(ses, server) == CIFS_INVAL_CHAN_INDEX) { @@ -1963,31 +1969,6 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) return rc; } -/** - * cifs_free_ipc - helper to release the session IPC tcon - * @ses: smb session to unmount the IPC from - * - * Needs to be called everytime a session is destroyed. - * - * On session close, the IPC is closed and the server must release all tcons of the session. - * No need to send a tree disconnect here. - * - * Besides, it will make the server to not close durable and resilient files on session close, as - * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request. - */ -static int -cifs_free_ipc(struct cifs_ses *ses) -{ - struct cifs_tcon *tcon = ses->tcon_ipc; - - if (tcon == NULL) - return 0; - - tconInfoFree(tcon); - ses->tcon_ipc = NULL; - return 0; -} - static struct cifs_ses * cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { @@ -2019,48 +2000,52 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) void __cifs_put_smb_ses(struct cifs_ses *ses) { struct TCP_Server_Info *server = ses->server; + struct cifs_tcon *tcon; unsigned int xid; size_t i; + bool do_logoff; int rc; - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING) { - spin_unlock(&ses->ses_lock); - return; - } - spin_unlock(&ses->ses_lock); - - cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); - cifs_dbg(FYI, - "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE"); - spin_lock(&cifs_tcp_ses_lock); - if (--ses->ses_count > 0) { + spin_lock(&ses->ses_lock); + cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n", + __func__, ses->Suid, ses->ses_count, ses->ses_status, + ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none"); + if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) { + spin_unlock(&ses->ses_lock); spin_unlock(&cifs_tcp_ses_lock); return; } - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_GOOD) - ses->ses_status = SES_EXITING; - spin_unlock(&ses->ses_lock); - spin_unlock(&cifs_tcp_ses_lock); - /* ses_count can never go negative */ WARN_ON(ses->ses_count < 0); - spin_lock(&ses->ses_lock); - if (ses->ses_status == SES_EXITING && server->ops->logoff) { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); + spin_lock(&ses->chan_lock); + cifs_chan_clear_need_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + + do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff; + ses->ses_status = SES_EXITING; + tcon = ses->tcon_ipc; + ses->tcon_ipc = NULL; + spin_unlock(&ses->ses_lock); + spin_unlock(&cifs_tcp_ses_lock); + + /* + * On session close, the IPC is closed and the server must release all + * tcons of the session. No need to send a tree disconnect here. + * + * Besides, it will make the server to not close durable and resilient + * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an + * SMB2 LOGOFF Request. + */ + tconInfoFree(tcon); + if (do_logoff) { xid = get_xid(); rc = server->ops->logoff(xid, ses); if (rc) cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n", __func__, rc); _free_xid(xid); - } else { - spin_unlock(&ses->ses_lock); - cifs_free_ipc(ses); } spin_lock(&cifs_tcp_ses_lock);

9 months

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FAILED: patch "[PATCH] riscv: process: Fix kernel gp leakage" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x d14fa1fcf69db9d070e75f1c4425211fa619dfc8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040817-unplowed-heavily-b59d@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: d14fa1fcf69d ("riscv: process: Fix kernel gp leakage") fea2fed201ee ("riscv: Enable per-task stack canaries") d7071743db31 ("RISC-V: Add EFI stub support.") f2c9699f6555 ("riscv: Add STACKPROTECTOR supported") a5d8e55b2c7d ("Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixes") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d14fa1fcf69db9d070e75f1c4425211fa619dfc8 Mon Sep 17 00:00:00 2001 From: Stefan O'Rear <sorear(a)fastmail.com> Date: Wed, 27 Mar 2024 02:12:58 -0400 Subject: [PATCH] riscv: process: Fix kernel gp leakage childregs represents the registers which are active for the new thread in user context. For a kernel thread, childregs->gp is never used since the kernel gp is not touched by switch_to. For a user mode helper, the gp value can be observed in user space after execve or possibly by other means. [From the email thread] The /* Kernel thread */ comment is somewhat inaccurate in that it is also used for user_mode_helper threads, which exec a user process, e.g. /sbin/init or when /proc/sys/kernel/core_pattern is a pipe. Such threads do not have PF_KTHREAD set and are valid targets for ptrace etc. even before they exec. childregs is the *user* context during syscall execution and it is observable from userspace in at least five ways: 1. kernel_execve does not currently clear integer registers, so the starting register state for PID 1 and other user processes started by the kernel has sp = user stack, gp = kernel __global_pointer$, all other integer registers zeroed by the memset in the patch comment. This is a bug in its own right, but I'm unwilling to bet that it is the only way to exploit the issue addressed by this patch. 2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread before it execs, but ptrace requires SIGSTOP to be delivered which can only happen at user/kernel boundaries. 3. /proc/*/task/*/syscall: this is perfectly happy to read pt_regs for user_mode_helpers before the exec completes, but gp is not one of the registers it returns. 4. PERF_SAMPLE_REGS_USER: LOCKDOWN_PERF normally prevents access to kernel addresses via PERF_SAMPLE_REGS_INTR, but due to this bug kernel addresses are also exposed via PERF_SAMPLE_REGS_USER which is permitted under LOCKDOWN_PERF. I have not attempted to write exploit code. 5. Much of the tracing infrastructure allows access to user registers. I have not attempted to determine which forms of tracing allow access to user registers without already allowing access to kernel registers. Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Cc: stable(a)vger.kernel.org Signed-off-by: Stefan O'Rear <sorear(a)fastmail.com> Reviewed-by: Alexandre Ghiti <alexghiti(a)rivosinc.com> Link: https://lore.kernel.org/r/20240327061258.2370291-1-sorear@fastmail.com Signed-off-by: Palmer Dabbelt <palmer(a)rivosinc.com> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 6abeecbfc51d..e4bc61c4e58a 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -27,8 +27,6 @@ #include <asm/vector.h> #include <asm/cpufeature.h> -register unsigned long gp_in_global __asm__("gp"); - #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) #include <linux/stackprotector.h> unsigned long __stack_chk_guard __read_mostly; @@ -207,7 +205,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (unlikely(args->fn)) { /* Kernel thread */ memset(childregs, 0, sizeof(struct pt_regs)); - childregs->gp = gp_in_global; /* Supervisor/Machine, irqs on: */ childregs->status = SR_PP | SR_PIE;

9 months

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FAILED: patch "[PATCH] riscv: process: Fix kernel gp leakage" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x d14fa1fcf69db9d070e75f1c4425211fa619dfc8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040815-geometric-quaintly-f4a7@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: d14fa1fcf69d ("riscv: process: Fix kernel gp leakage") fea2fed201ee ("riscv: Enable per-task stack canaries") d7071743db31 ("RISC-V: Add EFI stub support.") f2c9699f6555 ("riscv: Add STACKPROTECTOR supported") a5d8e55b2c7d ("Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixes") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d14fa1fcf69db9d070e75f1c4425211fa619dfc8 Mon Sep 17 00:00:00 2001 From: Stefan O'Rear <sorear(a)fastmail.com> Date: Wed, 27 Mar 2024 02:12:58 -0400 Subject: [PATCH] riscv: process: Fix kernel gp leakage childregs represents the registers which are active for the new thread in user context. For a kernel thread, childregs->gp is never used since the kernel gp is not touched by switch_to. For a user mode helper, the gp value can be observed in user space after execve or possibly by other means. [From the email thread] The /* Kernel thread */ comment is somewhat inaccurate in that it is also used for user_mode_helper threads, which exec a user process, e.g. /sbin/init or when /proc/sys/kernel/core_pattern is a pipe. Such threads do not have PF_KTHREAD set and are valid targets for ptrace etc. even before they exec. childregs is the *user* context during syscall execution and it is observable from userspace in at least five ways: 1. kernel_execve does not currently clear integer registers, so the starting register state for PID 1 and other user processes started by the kernel has sp = user stack, gp = kernel __global_pointer$, all other integer registers zeroed by the memset in the patch comment. This is a bug in its own right, but I'm unwilling to bet that it is the only way to exploit the issue addressed by this patch. 2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread before it execs, but ptrace requires SIGSTOP to be delivered which can only happen at user/kernel boundaries. 3. /proc/*/task/*/syscall: this is perfectly happy to read pt_regs for user_mode_helpers before the exec completes, but gp is not one of the registers it returns. 4. PERF_SAMPLE_REGS_USER: LOCKDOWN_PERF normally prevents access to kernel addresses via PERF_SAMPLE_REGS_INTR, but due to this bug kernel addresses are also exposed via PERF_SAMPLE_REGS_USER which is permitted under LOCKDOWN_PERF. I have not attempted to write exploit code. 5. Much of the tracing infrastructure allows access to user registers. I have not attempted to determine which forms of tracing allow access to user registers without already allowing access to kernel registers. Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Cc: stable(a)vger.kernel.org Signed-off-by: Stefan O'Rear <sorear(a)fastmail.com> Reviewed-by: Alexandre Ghiti <alexghiti(a)rivosinc.com> Link: https://lore.kernel.org/r/20240327061258.2370291-1-sorear@fastmail.com Signed-off-by: Palmer Dabbelt <palmer(a)rivosinc.com> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 6abeecbfc51d..e4bc61c4e58a 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -27,8 +27,6 @@ #include <asm/vector.h> #include <asm/cpufeature.h> -register unsigned long gp_in_global __asm__("gp"); - #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) #include <linux/stackprotector.h> unsigned long __stack_chk_guard __read_mostly; @@ -207,7 +205,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (unlikely(args->fn)) { /* Kernel thread */ memset(childregs, 0, sizeof(struct pt_regs)); - childregs->gp = gp_in_global; /* Supervisor/Machine, irqs on: */ childregs->status = SR_PP | SR_PIE;

9 months

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FAILED: patch "[PATCH] riscv: process: Fix kernel gp leakage" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x d14fa1fcf69db9d070e75f1c4425211fa619dfc8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040813-decline-blinker-ebc3@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: d14fa1fcf69d ("riscv: process: Fix kernel gp leakage") fea2fed201ee ("riscv: Enable per-task stack canaries") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d14fa1fcf69db9d070e75f1c4425211fa619dfc8 Mon Sep 17 00:00:00 2001 From: Stefan O'Rear <sorear(a)fastmail.com> Date: Wed, 27 Mar 2024 02:12:58 -0400 Subject: [PATCH] riscv: process: Fix kernel gp leakage childregs represents the registers which are active for the new thread in user context. For a kernel thread, childregs->gp is never used since the kernel gp is not touched by switch_to. For a user mode helper, the gp value can be observed in user space after execve or possibly by other means. [From the email thread] The /* Kernel thread */ comment is somewhat inaccurate in that it is also used for user_mode_helper threads, which exec a user process, e.g. /sbin/init or when /proc/sys/kernel/core_pattern is a pipe. Such threads do not have PF_KTHREAD set and are valid targets for ptrace etc. even before they exec. childregs is the *user* context during syscall execution and it is observable from userspace in at least five ways: 1. kernel_execve does not currently clear integer registers, so the starting register state for PID 1 and other user processes started by the kernel has sp = user stack, gp = kernel __global_pointer$, all other integer registers zeroed by the memset in the patch comment. This is a bug in its own right, but I'm unwilling to bet that it is the only way to exploit the issue addressed by this patch. 2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread before it execs, but ptrace requires SIGSTOP to be delivered which can only happen at user/kernel boundaries. 3. /proc/*/task/*/syscall: this is perfectly happy to read pt_regs for user_mode_helpers before the exec completes, but gp is not one of the registers it returns. 4. PERF_SAMPLE_REGS_USER: LOCKDOWN_PERF normally prevents access to kernel addresses via PERF_SAMPLE_REGS_INTR, but due to this bug kernel addresses are also exposed via PERF_SAMPLE_REGS_USER which is permitted under LOCKDOWN_PERF. I have not attempted to write exploit code. 5. Much of the tracing infrastructure allows access to user registers. I have not attempted to determine which forms of tracing allow access to user registers without already allowing access to kernel registers. Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Cc: stable(a)vger.kernel.org Signed-off-by: Stefan O'Rear <sorear(a)fastmail.com> Reviewed-by: Alexandre Ghiti <alexghiti(a)rivosinc.com> Link: https://lore.kernel.org/r/20240327061258.2370291-1-sorear@fastmail.com Signed-off-by: Palmer Dabbelt <palmer(a)rivosinc.com> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 6abeecbfc51d..e4bc61c4e58a 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -27,8 +27,6 @@ #include <asm/vector.h> #include <asm/cpufeature.h> -register unsigned long gp_in_global __asm__("gp"); - #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) #include <linux/stackprotector.h> unsigned long __stack_chk_guard __read_mostly; @@ -207,7 +205,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (unlikely(args->fn)) { /* Kernel thread */ memset(childregs, 0, sizeof(struct pt_regs)); - childregs->gp = gp_in_global; /* Supervisor/Machine, irqs on: */ childregs->status = SR_PP | SR_PIE;

9 months

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