Hi Namjae, Steve,
Thanks for updating the patch. I’ve reviewed the changes and they look good to me.
Minor impact note: this patch prevents a 4-byte out-of-bounds read in ksmbd's handle_response() when the declared Generic Netlink payload size is < 4. If a remote client can influence ksmbd.mountd to emit a truncated payload, this could be remotely triggerable (info-leak/DoS potential). If you consider this security-impacting, I’m happy to request a CVE via the kernel.org CNA.
Thanks!! Qianchang Zhao
On Wed, Oct 22, 2025 at 3:39 PM Namjae Jeon linkinjeon@kernel.org wrote:
On Tue, Oct 21, 2025 at 11:55 PM Qianchang Zhao pioooooooooip@gmail.com wrote:
handle_response() dereferences the payload as a 4-byte handle without verifying that the declared payload size is at least 4 bytes. A malformed or truncated message from ksmbd.mountd can lead to a 4-byte read past the declared payload size. Validate the size before dereferencing.
This is a minimal fix to guard the initial handle read.
Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Cc: stable@vger.kernel.org Reported-by: Qianchang Zhao pioooooooooip@gmail.com Signed-off-by: Qianchang Zhao pioooooooooip@gmail.com
I have directly updated your patch. Can you check the attached patch ? Thanks!