6.1-stable review patch. If anyone has any objections, please let me know.
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From: Makar Semyonov m.semenov@tssltd.ru
commit 70bccd9855dae56942f2b18a08ba137bb54093a0 upstream.
There can be a NULL pointer dereference bug here. NULL is passed to __cifs_sfu_make_node without checks, which passes it unchecked to cifs_strndup_to_utf16, which in turn passes it to cifs_local_to_utf16_bytes where '*from' is dereferenced, causing a crash.
This patch adds a check for NULL 'src' in cifs_strndup_to_utf16 and returns NULL early to prevent dereferencing NULL pointer.
Found by Linux Verification Center (linuxtesting.org) with SVACE
Signed-off-by: Makar Semyonov m.semenov@tssltd.ru Cc: stable@vger.kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/cifs_unicode.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/smb/client/cifs_unicode.c +++ b/fs/smb/client/cifs_unicode.c @@ -619,6 +619,9 @@ cifs_strndup_to_utf16(const char *src, c int len; __le16 *dst;
+ if (!src) + return NULL; + len = cifs_local_to_utf16_bytes(src, maxlen, cp); len += 2; /* NULL */ dst = kmalloc(len, GFP_KERNEL);