cifs: fix out-of-bound memory access when calling smb3_notify() at mount point

Browse source

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>

...

This commit is contained in:

Eugene Korenevsky 2021-04-16 10:35:30 +03:00 • committed by Steve French

parent ccd48ec3d4

commit a637f4ae03

1 changed files with 1 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

2

fs/cifs/smb2ops.c

View file