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;