On Tue, Nov 4, 2025 at 7:03 PM Qianchang Zhao pioooooooooip@gmail.com wrote:

When encrypt_resp() fails at the send path, we only set STATUS_DATA_ERROR but leave the transform buffer allocated (work->tr_buf in this tree). Repeating this path leaks kernel memory and can lead to OOM (DoS) when encryption is required.

Reproduced on: Linux v6.18-rc2 (self-built test kernel)

Fix by freeing the transform buffer and forcing plaintext error reply.

Reported-by: Qianchang Zhao pioooooooooip@gmail.com Reported-by: Zhitong Liu liuzhitong1993@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Qianchang Zhao pioooooooooip@gmail.com

---

fs/smb/server/server.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c index 7b01c7589..15dd13e76 100644 --- a/fs/smb/server/server.c +++ b/fs/smb/server/server.c @@ -246,11 +246,11 @@ static void __handle_ksmbd_work(struct ksmbd_work *work, rc = conn->ops->encrypt_resp(work); if (rc < 0) { conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);

•                    work->encrypted = false;
  

•                           if (work->tr_buf) {
  

•                                   kvfree(work->tr_buf);
  

•                                   work->tr_buf = NULL;
  

•                                   }
  

•                   work->encrypted = false;
  

•                   if (work->tr_buf) {
  

•                           kvfree(work->tr_buf);
  

•                           work->tr_buf = NULL;
  

•                   }
  

This patch seems to be broken or wrong. Please check the patch again. Thanks!

            }
    }
    if (work->sess)

-- 2.34.1