This is a note to let you know that I've just added the patch titled
cifs: fix out-of-bound memory access when calling smb3_notify() at mount point
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cifs-fix-out-of-bound-memory-access-when-calling-smb3_notify-at-mount-point.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a637f4ae037e1e0604ac008564934d63261a8fd1 Mon Sep 17 00:00:00 2001
From: Eugene Korenevsky <ekorenevsky@xxxxxxxxxxxxx>
Date: Fri, 16 Apr 2021 10:35:30 +0300
Subject: cifs: fix out-of-bound memory access when calling smb3_notify() at mount point
From: Eugene Korenevsky <ekorenevsky@xxxxxxxxxxxxx>
commit a637f4ae037e1e0604ac008564934d63261a8fd1 upstream.
If smb3_notify() is called at mount point of CIFS, build_path_from_dentry()
returns the pointer to kmalloc-ed memory with terminating zero (this is
empty FileName to be passed to SMB2 CREATE request). This pointer is assigned
to the `path` variable.
Then `path + 1` (to skip first backslash symbol) is passed to
cifs_convert_path_to_utf16(). This is incorrect for empty path and causes
out-of-bound memory access.
Get rid of this "increase by one". cifs_convert_path_to_utf16() already
contains the check for leading backslash in the path.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=212693
CC: <stable@xxxxxxxxxxxxxxx> # v5.6+
Signed-off-by: Eugene Korenevsky <ekorenevsky@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/smb2ops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2174,7 +2174,7 @@ smb3_notify(const unsigned int xid, stru
cifs_sb = CIFS_SB(inode->i_sb);
- utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb);
+ utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
if (utf16_path == NULL) {
rc = -ENOMEM;
goto notify_exit;
Patches currently in stable-queue which might be from ekorenevsky@xxxxxxxxxxxxx are
queue-5.10/cifs-fix-out-of-bound-memory-access-when-calling-smb3_notify-at-mount-point.patch
