FAILED: patch "[PATCH] ksmbd: smbdirect: validate data_offset and data_length field" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 5282491fc49d5614ac6ddcd012e5743eecb6a67c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025092118-portside-cheesy-44d2@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5282491fc49d5614ac6ddcd012e5743eecb6a67c Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@kernel.org>
Date: Wed, 10 Sep 2025 11:22:52 +0900
Subject: [PATCH] ksmbd: smbdirect: validate data_offset and data_length field
 of smb_direct_data_transfer

If data_offset and data_length of smb_direct_data_transfer struct are
invalid, out of bounds issue could happen.
This patch validate data_offset and data_length field in recv_done.

Cc: stable@vger.kernel.org
Fixes: 2ea086e35c3d ("ksmbd: add buffer validation for smb direct")
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reported-by: Luigino Camastra, Aisle Research <luigino.camastra@aisle.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c
index cc4322bfa1d6..d52f37578276 100644
--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -554,7 +554,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 	case SMB_DIRECT_MSG_DATA_TRANSFER: {
 		struct smb_direct_data_transfer *data_transfer =
 			(struct smb_direct_data_transfer *)recvmsg->packet;
-		unsigned int data_length;
+		unsigned int data_offset, data_length;
 		int avail_recvmsg_count, receive_credits;
 
 		if (wc->byte_len <
@@ -565,14 +565,15 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 		}
 
 		data_length = le32_to_cpu(data_transfer->data_length);
-		if (data_length) {
-			if (wc->byte_len < sizeof(struct smb_direct_data_transfer) +
-			    (u64)data_length) {
-				put_recvmsg(t, recvmsg);
-				smb_direct_disconnect_rdma_connection(t);
-				return;
-			}
+		data_offset = le32_to_cpu(data_transfer->data_offset);
+		if (wc->byte_len < data_offset ||
+		    wc->byte_len < (u64)data_offset + data_length) {
+			put_recvmsg(t, recvmsg);
+			smb_direct_disconnect_rdma_connection(t);
+			return;
+		}
 
+		if (data_length) {
 			if (t->full_packet_received)
 				recvmsg->first_segment = true;