From: Stefan Metzmacher Date: Thu, 11 Sep 2025 01:05:23 +0000 (+0900) Subject: ksmbd: smbdirect: verify remaining_data_length respects max_fragmented_recv_size X-Git-Tag: v6.12.49~71 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9644798294c7287e65a7b26e35aa6d2ce3345bcc;p=thirdparty%2Fkernel%2Fstable.git ksmbd: smbdirect: verify remaining_data_length respects max_fragmented_recv_size commit e1868ba37fd27c6a68e31565402b154beaa65df0 upstream. This is inspired by the check for data_offset + data_length. Cc: Steve French Cc: Tom Talpey Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Cc: stable@vger.kernel.org Fixes: 2ea086e35c3d ("ksmbd: add buffer validation for smb direct") Acked-by: Namjae Jeon Signed-off-by: Stefan Metzmacher Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c index 60714f9fb1b40..2fc689f99997e 100644 --- a/fs/smb/server/transport_rdma.c +++ b/fs/smb/server/transport_rdma.c @@ -553,7 +553,7 @@ 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_offset, data_length; + u32 remaining_data_length, data_offset, data_length; int avail_recvmsg_count, receive_credits; if (wc->byte_len < @@ -563,6 +563,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) return; } + remaining_data_length = le32_to_cpu(data_transfer->remaining_data_length); data_length = le32_to_cpu(data_transfer->data_length); data_offset = le32_to_cpu(data_transfer->data_offset); if (wc->byte_len < data_offset || @@ -571,6 +572,14 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) smb_direct_disconnect_rdma_connection(t); return; } + if (remaining_data_length > t->max_fragmented_recv_size || + data_length > t->max_fragmented_recv_size || + (u64)remaining_data_length + (u64)data_length > + (u64)t->max_fragmented_recv_size) { + put_recvmsg(t, recvmsg); + smb_direct_disconnect_rdma_connection(t); + return; + } if (data_length) { if (t->full_packet_received)