From: Qianchang Zhao pioooooooooip@gmail.com
[ Upstream commit 6f40e50ceb99fc8ef37e5c56e2ec1d162733fef0 ]
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 Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com [ applied patch to fs/ksmbd/transport_ipc.c instead of fs/smb/server/transport_ipc.c ] Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ksmbd/transport_ipc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/ksmbd/transport_ipc.c b/fs/ksmbd/transport_ipc.c index 7e6003c6cd9bf..1d57426e9e022 100644 --- a/fs/ksmbd/transport_ipc.c +++ b/fs/ksmbd/transport_ipc.c @@ -248,10 +248,16 @@ static void ipc_msg_handle_free(int handle)
static int handle_response(int type, void *payload, size_t sz) { - unsigned int handle = *(unsigned int *)payload; + unsigned int handle; struct ipc_msg_table_entry *entry; int ret = 0;
+ /* Prevent 4-byte read beyond declared payload size */ + if (sz < sizeof(unsigned int)) + return -EINVAL; + + handle = *(unsigned int *)payload; + ipc_update_last_active(); down_read(&ipc_msg_table_lock); hash_for_each_possible(ipc_msg_table, entry, ipc_table_hlist, handle) {