April 2024 - Linux-stable-mirror

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);

1 year, 2 months

1
0
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);

1 year, 2 months

1
0
0 0

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;

1 year, 2 months

1
0
0 0

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;

1 year, 2 months

1
0
0 0

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;

1 year, 2 months

1
0
0 0

[PATCH] drm/xe: Fix bo leak in intel_fb_bo_framebuffer_init

by Maarten Lankhorst

Add a unreference bo in the error path, to prevent leaking a bo ref. Return 0 on success to clarify the success path. Signed-off-by: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Fixes: 44e694958b95 ("drm/xe/display: Implement display support") Cc: <stable(a)vger.kernel.org> # v6.8+ --- drivers/gpu/drm/xe/display/intel_fb_bo.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/xe/display/intel_fb_bo.c b/drivers/gpu/drm/xe/display/intel_fb_bo.c index dba327f53ac5..e18521acc516 100644 --- a/drivers/gpu/drm/xe/display/intel_fb_bo.c +++ b/drivers/gpu/drm/xe/display/intel_fb_bo.c @@ -31,7 +31,7 @@ int intel_fb_bo_framebuffer_init(struct intel_framebuffer *intel_fb, ret = ttm_bo_reserve(&bo->ttm, true, false, NULL); if (ret) - return ret; + goto err; if (!(bo->flags & XE_BO_FLAG_SCANOUT)) { /* @@ -42,12 +42,16 @@ int intel_fb_bo_framebuffer_init(struct intel_framebuffer *intel_fb, */ if (XE_IOCTL_DBG(i915, !list_empty(&bo->ttm.base.gpuva.list))) { ttm_bo_unreserve(&bo->ttm); - return -EINVAL; + ret = -EINVAL; + goto err; } bo->flags |= XE_BO_FLAG_SCANOUT; } ttm_bo_unreserve(&bo->ttm); + return 0; +err: + xe_bo_put(bo); return ret; } -- 2.43.0

1 year, 2 months

2
1
0 0

Re: Patch "ASoC: tas2781: mark dvc_tlv with __maybe_unused" has been added to the 6.8-stable tree

by Gergo Koteles

Hi, On Sun, 2024-04-07 at 16:13 -0400, Sasha Levin wrote: > This is a note to let you know that I've just added the patch titled > > ASoC: tas2781: mark dvc_tlv with __maybe_unused > > to the 6.8-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… > > The filename of the patch is: > asoc-tas2781-mark-dvc_tlv-with-__maybe_unused.patch > and it can be found in the queue-6.8 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <stable(a)vger.kernel.org> know about it. > > Is this necessary for stable? It only fixes a W=1 build warning. Regards, Gergo

1 year, 2 months

2
1
0 0

[PATCH v3 0/3] arm64: dts: hi3798cv200: fix GICR size, add cache info, maintenance irq and GICH, GICV spaces

by Yang Xiwen via B4 Relay

The patchset fixes some warnings reported by the kernel during boot. The cache size info is from Processor_Datasheet_v2XX.pdf [1], Section 2.2.1 Master Processor. The cache line size and the set-associative info are from Cortex-A53 Documentation [2]. From the doc, it can be concluded that L1 i-cache is 4-way assoc, L1 d-cache is 2-way assoc and L2 cache is 16-way assoc. Calculate the dts props accordingly. Also, to use KVM's VGIC code, GICH, GICV registers spaces and maintenance IRQ are added to the dts with verification. [1]: https://github.com/96boards/documentation/blob/master/enterprise/poplar/har… [2]: https://developer.arm.com/documentation/ddi0500/j/Level-1-Memory-System Signed-off-by: Yang Xiwen <forbidden405(a)outlook.com> --- Changes in v3: - send patches to stable (Andrew Lunn) - rewrite the commit logs more formally (Andrew Lunn) - rename l2-cache0 to l2-cache (Krzysztof Kozlowski) - Link to v2: https://lore.kernel.org/r/20240218-cache-v2-0-1fd919e2bd3e@outlook.com Changes in v2: - arm64: dts: hi3798cv200: add GICH, GICV register spces and maintainance IRQ. - Link to v1: https://lore.kernel.org/r/20240218-cache-v1-0-2c0a8a4472e7@outlook.com --- Yang Xiwen (3): arm64: dts: hi3798cv200: fix the size of GICR arm64: dts: hi3798cv200: add GICH, GICV register space and irq arm64: dts: hi3798cv200: add cache info arch/arm64/boot/dts/hisilicon/hi3798cv200.dtsi | 43 +++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) --- base-commit: 8d3dea210042f54b952b481838c1e7dfc4ec751d change-id: 20240218-cache-11c8bf7566c2 Best regards, -- Yang Xiwen <forbidden405(a)outlook.com>

1 year, 2 months

5
13
0 0

[PATCH 6/8] accel/ivpu: Return max freq for DRM_IVPU_PARAM_CORE_CLOCK_RATE

by Jacek Lawrynowicz

DRM_IVPU_PARAM_CORE_CLOCK_RATE returned current NPU frequency which could be 0 if device was sleeping. This value wasn't really useful to the user space, so return max freq instead which can be used to estimate NPU performance. Fixes: c39dc15191c4 ("accel/ivpu: Read clock rate only if device is up") Cc: <stable(a)vger.kernel.org> # v6.7 Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz(a)linux.intel.com> --- drivers/accel/ivpu/ivpu_drv.c | 18 +----------------- drivers/accel/ivpu/ivpu_hw.h | 6 ++++++ drivers/accel/ivpu/ivpu_hw_37xx.c | 7 ++++--- drivers/accel/ivpu/ivpu_hw_40xx.c | 6 ++++++ 4 files changed, 17 insertions(+), 20 deletions(-) diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c index 303d92753387..77283daaedd1 100644 --- a/drivers/accel/ivpu/ivpu_drv.c +++ b/drivers/accel/ivpu/ivpu_drv.c @@ -131,22 +131,6 @@ static int ivpu_get_capabilities(struct ivpu_device *vdev, struct drm_ivpu_param return 0; } -static int ivpu_get_core_clock_rate(struct ivpu_device *vdev, u64 *clk_rate) -{ - int ret; - - ret = ivpu_rpm_get_if_active(vdev); - if (ret < 0) - return ret; - - *clk_rate = ret ? ivpu_hw_reg_pll_freq_get(vdev) : 0; - - if (ret) - ivpu_rpm_put(vdev); - - return 0; -} - static int ivpu_get_param_ioctl(struct drm_device *dev, void *data, struct drm_file *file) { struct ivpu_file_priv *file_priv = file->driver_priv; @@ -170,7 +154,7 @@ static int ivpu_get_param_ioctl(struct drm_device *dev, void *data, struct drm_f args->value = vdev->platform; break; case DRM_IVPU_PARAM_CORE_CLOCK_RATE: - ret = ivpu_get_core_clock_rate(vdev, &args->value); + args->value = ivpu_hw_ratio_to_freq(vdev, vdev->hw->pll.max_ratio); break; case DRM_IVPU_PARAM_NUM_CONTEXTS: args->value = ivpu_get_context_count(vdev); diff --git a/drivers/accel/ivpu/ivpu_hw.h b/drivers/accel/ivpu/ivpu_hw.h index b2909168a0a6..094c659d2800 100644 --- a/drivers/accel/ivpu/ivpu_hw.h +++ b/drivers/accel/ivpu/ivpu_hw.h @@ -21,6 +21,7 @@ struct ivpu_hw_ops { u32 (*profiling_freq_get)(struct ivpu_device *vdev); void (*profiling_freq_drive)(struct ivpu_device *vdev, bool enable); u32 (*reg_pll_freq_get)(struct ivpu_device *vdev); + u32 (*ratio_to_freq)(struct ivpu_device *vdev, u32 ratio); u32 (*reg_telemetry_offset_get)(struct ivpu_device *vdev); u32 (*reg_telemetry_size_get)(struct ivpu_device *vdev); u32 (*reg_telemetry_enable_get)(struct ivpu_device *vdev); @@ -130,6 +131,11 @@ static inline u32 ivpu_hw_reg_pll_freq_get(struct ivpu_device *vdev) return vdev->hw->ops->reg_pll_freq_get(vdev); }; +static inline u32 ivpu_hw_ratio_to_freq(struct ivpu_device *vdev, u32 ratio) +{ + return vdev->hw->ops->ratio_to_freq(vdev, ratio); +} + static inline u32 ivpu_hw_reg_telemetry_offset_get(struct ivpu_device *vdev) { return vdev->hw->ops->reg_telemetry_offset_get(vdev); diff --git a/drivers/accel/ivpu/ivpu_hw_37xx.c b/drivers/accel/ivpu/ivpu_hw_37xx.c index 5e2865f9f7d6..bd25e2d9fb0f 100644 --- a/drivers/accel/ivpu/ivpu_hw_37xx.c +++ b/drivers/accel/ivpu/ivpu_hw_37xx.c @@ -803,12 +803,12 @@ static void ivpu_hw_37xx_profiling_freq_drive(struct ivpu_device *vdev, bool ena /* Profiling freq - is a debug feature. Unavailable on VPU 37XX. */ } -static u32 ivpu_hw_37xx_pll_to_freq(u32 ratio, u32 config) +static u32 ivpu_hw_37xx_ratio_to_freq(struct ivpu_device *vdev, u32 ratio) { u32 pll_clock = PLL_REF_CLK_FREQ * ratio; u32 cpu_clock; - if ((config & 0xff) == PLL_RATIO_4_3) + if ((vdev->hw->config & 0xff) == PLL_RATIO_4_3) cpu_clock = pll_clock * 2 / 4; else cpu_clock = pll_clock * 2 / 5; @@ -827,7 +827,7 @@ static u32 ivpu_hw_37xx_reg_pll_freq_get(struct ivpu_device *vdev) if (!ivpu_is_silicon(vdev)) return PLL_SIMULATION_FREQ; - return ivpu_hw_37xx_pll_to_freq(pll_curr_ratio, vdev->hw->config); + return ivpu_hw_37xx_ratio_to_freq(vdev, pll_curr_ratio); } static u32 ivpu_hw_37xx_reg_telemetry_offset_get(struct ivpu_device *vdev) @@ -1050,6 +1050,7 @@ const struct ivpu_hw_ops ivpu_hw_37xx_ops = { .profiling_freq_get = ivpu_hw_37xx_profiling_freq_get, .profiling_freq_drive = ivpu_hw_37xx_profiling_freq_drive, .reg_pll_freq_get = ivpu_hw_37xx_reg_pll_freq_get, + .ratio_to_freq = ivpu_hw_37xx_ratio_to_freq, .reg_telemetry_offset_get = ivpu_hw_37xx_reg_telemetry_offset_get, .reg_telemetry_size_get = ivpu_hw_37xx_reg_telemetry_size_get, .reg_telemetry_enable_get = ivpu_hw_37xx_reg_telemetry_enable_get, diff --git a/drivers/accel/ivpu/ivpu_hw_40xx.c b/drivers/accel/ivpu/ivpu_hw_40xx.c index e4eddbf5d11c..b0b88d4c8926 100644 --- a/drivers/accel/ivpu/ivpu_hw_40xx.c +++ b/drivers/accel/ivpu/ivpu_hw_40xx.c @@ -980,6 +980,11 @@ static u32 ivpu_hw_40xx_reg_pll_freq_get(struct ivpu_device *vdev) return PLL_RATIO_TO_FREQ(pll_curr_ratio); } +static u32 ivpu_hw_40xx_ratio_to_freq(struct ivpu_device *vdev, u32 ratio) +{ + return PLL_RATIO_TO_FREQ(ratio); +} + static u32 ivpu_hw_40xx_reg_telemetry_offset_get(struct ivpu_device *vdev) { return REGB_RD32(VPU_40XX_BUTTRESS_VPU_TELEMETRY_OFFSET); @@ -1230,6 +1235,7 @@ const struct ivpu_hw_ops ivpu_hw_40xx_ops = { .profiling_freq_get = ivpu_hw_40xx_profiling_freq_get, .profiling_freq_drive = ivpu_hw_40xx_profiling_freq_drive, .reg_pll_freq_get = ivpu_hw_40xx_reg_pll_freq_get, + .ratio_to_freq = ivpu_hw_40xx_ratio_to_freq, .reg_telemetry_offset_get = ivpu_hw_40xx_reg_telemetry_offset_get, .reg_telemetry_size_get = ivpu_hw_40xx_reg_telemetry_size_get, .reg_telemetry_enable_get = ivpu_hw_40xx_reg_telemetry_enable_get, -- 2.43.2

1 year, 2 months

2
2
0 0

[PATCH v5 00/10] x86/sev: KEXEC/KDUMP support for SEV-ES guests

by vsntk18＠gmail.com

From: Vasant Karasulli <vkarasulli(a)suse.de> Hi, here are changes to enable kexec/kdump in SEV-ES guests. The biggest problem for supporting kexec/kdump under SEV-ES is to find a way to hand the non-boot CPUs (APs) from one kernel to another. Without SEV-ES the first kernel parks the CPUs in a HLT loop until they get reset by the kexec'ed kernel via an INIT-SIPI-SIPI sequence. For virtual machines the CPU reset is emulated by the hypervisor, which sets the vCPU registers back to reset state. This does not work under SEV-ES, because the hypervisor has no access to the vCPU registers and can't make modifications to them. So an SEV-ES guest needs to reset the vCPU itself and park it using the AP-reset-hold protocol. Upon wakeup the guest needs to jump to real-mode and to the reset-vector configured in the AP-Jump-Table. The code to do this is the main part of this patch-set. It works by placing code on the AP Jump-Table page itself to park the vCPU and for jumping to the reset vector upon wakeup. The code on the AP Jump Table runs in 16-bit protected mode with segment base set to the beginning of the page. The AP Jump-Table is usually not within the first 1MB of memory, so the code can't run in real-mode. The AP Jump-Table is the best place to put the parking code, because the memory is owned, but read-only by the firmware and writeable by the OS. Only the first 4 bytes are used for the reset-vector, leaving the rest of the page for code/data/stack to park a vCPU. The code can't be in kernel memory because by the time the vCPU wakes up the memory will be owned by the new kernel, which might have overwritten it already. The other patches add initial GHCB Version 2 protocol support, because kexec/kdump need the MSR-based (without a GHCB) AP-reset-hold VMGEXIT, which is a GHCB protocol version 2 feature. The kexec'ed kernel is also entered via the decompressor and needs MMIO support there, so this patch-set also adds MMIO #VC support to the decompressor and support for handling CLFLUSH instructions. Finally there is also code to disable kexec/kdump support at runtime when the environment does not support it (e.g. no GHCB protocol version 2 support or AP Jump Table over 4GB). The diffstat looks big, but most of it is moving code for MMIO #VC support around to make it available to the decompressor. The previous version of this patch-set can be found here: https://lore.kernel.org/kvm/20240311161727.14916-1-vsntk18@gmail.com/ Please review. Thanks, Vasant Changes v4->v5: - Rebased to v6.9-rc2 kernel - Applied review comments by Tom Lendacky - Exclude the AP jump table related code for SEV-SNP guests Changes v3->v4: - Rebased to v6.8 kernel - Applied review comments by Sean Christopherson - Combined sev_es_setup_ap_jump_table() and sev_setup_ap_jump_table() into a single function which makes caching jump table address unnecessary - annotated struct sev_ap_jump_table_header with __packed attribute - added code to set up real mode data segment at boot time instead of hardcoding the value. Changes v2->v3: - Rebased to v5.17-rc1 - Applied most review comments by Boris - Use the name 'AP jump table' consistently - Make kexec-disabling for unsupported guests x86-specific - Cleanup and consolidate patches to detect GHCB v2 protocol support Joerg Roedel (9): x86/kexec/64: Disable kexec when SEV-ES is active x86/sev: Save and print negotiated GHCB protocol version x86/sev: Set GHCB data structure version x86/sev: Setup code to park APs in the AP Jump Table x86/sev: Park APs on AP Jump Table with GHCB protocol version 2 x86/sev: Use AP Jump Table blob to stop CPU x86/sev: Add MMIO handling support to boot/compressed/ code x86/sev: Handle CLFLUSH MMIO events x86/kexec/64: Support kexec under SEV-ES with AP Jump Table Blob Vasant Karasulli (1): x86/sev: Exclude AP jump table related code for SEV-SNP guests arch/x86/boot/compressed/sev.c | 45 +- arch/x86/include/asm/insn-eval.h | 1 + arch/x86/include/asm/realmode.h | 5 + arch/x86/include/asm/sev-ap-jumptable.h | 30 + arch/x86/include/asm/sev.h | 7 + arch/x86/kernel/machine_kexec_64.c | 12 + arch/x86/kernel/process.c | 8 + arch/x86/kernel/sev-shared.c | 234 +++++- arch/x86/kernel/sev.c | 376 +++++----- arch/x86/lib/insn-eval-shared.c | 921 ++++++++++++++++++++++++ arch/x86/lib/insn-eval.c | 911 +---------------------- arch/x86/realmode/Makefile | 9 +- arch/x86/realmode/init.c | 5 +- arch/x86/realmode/rm/Makefile | 11 +- arch/x86/realmode/rm/header.S | 3 + arch/x86/realmode/rm/sev.S | 85 +++ arch/x86/realmode/rmpiggy.S | 6 + arch/x86/realmode/sev/Makefile | 33 + arch/x86/realmode/sev/ap_jump_table.S | 131 ++++ arch/x86/realmode/sev/ap_jump_table.lds | 24 + 20 files changed, 1711 insertions(+), 1146 deletions(-) create mode 100644 arch/x86/include/asm/sev-ap-jumptable.h create mode 100644 arch/x86/lib/insn-eval-shared.c create mode 100644 arch/x86/realmode/rm/sev.S create mode 100644 arch/x86/realmode/sev/Makefile create mode 100644 arch/x86/realmode/sev/ap_jump_table.S create mode 100644 arch/x86/realmode/sev/ap_jump_table.lds base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f -- 2.34.1

1 year, 2 months

2
10
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror April 2024