]> git.ipfire.org Git - thirdparty/linux.git/commit
cifs: fix out-of-bound memory access when calling smb3_notify() at mount point
authorEugene Korenevsky <ekorenevsky@astralinux.ru>
Fri, 16 Apr 2021 07:35:30 +0000 (10:35 +0300)
committerSteve French <stfrench@microsoft.com>
Sun, 25 Apr 2021 21:28:24 +0000 (16:28 -0500)
commita637f4ae037e1e0604ac008564934d63261a8fd1
tree6a493b841d7fc45d87431b30a7dd3e21ccac6c44
parentccd48ec3d4a6cc595b2d9c5146e63b6c23546701
cifs: fix out-of-bound memory access when calling smb3_notify() at mount point

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@vger.kernel.org> # v5.6+
Signed-off-by: Eugene Korenevsky <ekorenevsky@astralinux.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
fs/cifs/smb2ops.c