From: Dexuan Cui Date: Thu, 23 Apr 2026 06:48:11 +0000 (-0700) Subject: hv_sock: Return -EIO for malformed/short packets X-Git-Tag: v7.1-rc1~36^2~14 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d1f20727a635811f6b77801a7b57b8995268abd;p=thirdparty%2Fkernel%2Flinux.git hv_sock: Return -EIO for malformed/short packets Commit f63152958994 fixes a regression, however it fails to report an error for malformed/short packets -- normally we should never see such packets, but let's report an error for them just in case. Fixes: f63152958994 ("hv_sock: Report EOF instead of -EIO for FIN") Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui Acked-by: Stefano Garzarella Link: https://patch.msgid.link/20260423064811.1371749-1-decui@microsoft.com Signed-off-by: Jakub Kicinski --- diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c index 76e78c83fdbc..f862988c1e86 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -704,17 +704,26 @@ static s64 hvs_stream_has_data(struct vsock_sock *vsk) if (hvs->recv_desc) { /* Here hvs->recv_data_len is 0, so hvs->recv_desc must * be NULL unless it points to the 0-byte-payload FIN - * packet: see hvs_update_recv_data(). + * packet or a malformed/short packet: see + * hvs_update_recv_data(). * - * Here all the payload has been dequeued, but - * hvs_channel_readable_payload() still returns 1, - * because the VMBus ringbuffer's read_index is not - * updated for the FIN packet: hvs_stream_dequeue() -> - * hv_pkt_iter_next() updates the cached priv_read_index - * but has no opportunity to update the read_index in - * hv_pkt_iter_close() as hvs_stream_has_data() returns - * 0 for the FIN packet, so it won't get dequeued. + * If hvs->recv_desc points to the FIN packet, here all + * the payload has been dequeued and the peer_shutdown + * flag is set, but hvs_channel_readable_payload() still + * returns 1, because the VMBus ringbuffer's read_index + * is not updated for the FIN packet: + * hvs_stream_dequeue() -> hv_pkt_iter_next() updates + * the cached priv_read_index but has no opportunity to + * update the read_index in hv_pkt_iter_close() as + * hvs_stream_has_data() returns 0 for the FIN packet, + * so it won't get dequeued. + * + * In case hvs->recv_desc points to a malformed/short + * packet, return -EIO. */ + if (!(vsk->peer_shutdown & SEND_SHUTDOWN)) + return -EIO; + return 0; }