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@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 92414333eb375ed64f4ae92d34d579e826936480 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023121141-decoy-kennel-84d0@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
92414333eb37 ("smb: client: fix potential NULL deref in parse_dfs_referrals()") 38c8a9a52082 ("smb: move client and server files to common directory fs/smb") abdb1742a312 ("cifs: get rid of mount options string parsing") 9fd29a5bae6e ("cifs: use fs_context for automounts") 5dd8ce24667a ("cifs: missing directory in MAINTAINERS file") 332019e23a51 ("Merge tag '5.20-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 92414333eb375ed64f4ae92d34d579e826936480 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara pc@manguebit.com Date: Tue, 5 Dec 2023 21:49:29 -0300 Subject: [PATCH] smb: client: fix potential NULL deref in parse_dfs_referrals()
If server returned no data for FSCTL_DFS_GET_REFERRALS, @dfs_rsp will remain NULL and then parse_dfs_referrals() will dereference it.
Fix this by returning -EIO when no output data is returned.
Besides, we can't fix it in SMB2_ioctl() as some FSCTLs are allowed to return no data as per MS-SMB2 2.2.32.
Fixes: 9d49640a21bf ("CIFS: implement get_dfs_refer for SMB2+") Cc: stable@vger.kernel.org Reported-by: Robert Morris rtm@csail.mit.edu Signed-off-by: Paulo Alcantara (SUSE) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 45931115f475..fcfb6566b899 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -2836,6 +2836,8 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, usleep_range(512, 2048); } while (++retry_count < 5);
+ if (!rc && !dfs_rsp) + rc = -EIO; if (rc) { if (!is_retryable_error(rc) && rc != -ENOENT && rc != -EOPNOTSUPP) cifs_tcon_dbg(VFS, "%s: ioctl error: rc=%d\n", __func__, rc);