From 73f860489e3be2245598d1819226304fc5b87291 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Tue, 25 Aug 2026 09:31:35 +0900 Subject: [PATCH] ksmbd: zero pipe read compound padding Compound response handling extends the last response iov to an eight-byte boundary. smb2_read_pipe() allocates only the payload size, so the alignment padding can expose up to seven bytes of uninitialized kernel heap memory. Allocate the aligned size and clear the unused tail before pinning the response buffer. Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound") Reported-by: Cheryl Babcock Signed-off-by: Namjae Jeon --- fs/smb/server/smb2pdu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index ba0fe25bf366..8c589110460a 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -8657,13 +8657,18 @@ static noinline int smb2_read_pipe(struct ksmbd_work *work) } aux_payload_buf = - kvmalloc(rpc_resp->payload_sz, KSMBD_DEFAULT_GFP); + kvmalloc(ALIGN(rpc_resp->payload_sz, 8), + KSMBD_DEFAULT_GFP); if (!aux_payload_buf) { err = -ENOMEM; goto out; } memcpy(aux_payload_buf, rpc_resp->payload, rpc_resp->payload_sz); + if (rpc_resp->payload_sz & 7) + memset(aux_payload_buf + rpc_resp->payload_sz, 0, + ALIGN(rpc_resp->payload_sz, 8) - + rpc_resp->payload_sz); nbytes = rpc_resp->payload_sz; err = ksmbd_iov_pin_rsp_read(work, (void *)rsp,