qemu/virtio-net-drop-too-short-packets-early.patch
Jiabo Feng 841956ecbc QEMU update to version 8.2.0-21:
- tests: bump QOS_PATH_MAX_ELEMENT_SIZE again
- softmmu/physmem: fix memory leak in dirty_memory_extend()
- crypto: run qcrypto_pbkdf2_count_iters in a new thread
- hw/audio/virtio-sound: fix heap buffer overflow
- hw/intc/arm_gic: fix spurious level triggered interrupts
- ui/sdl2: set swap interval explicitly when OpenGL is enabled
- target/riscv/kvm: tolerate KVM disable ext errors
- virtio: remove virtio_tswap16s() call in vring_packed_event_read()
- block: fix -Werror=maybe-uninitialized false-positive
- hw/remote/vfio-user: Fix config space access byte order
- hw/loongarch/virt: Fix memory leak
- hw/intc/riscv_aplic: APLICs should add child earlier than realize
- stdvga: fix screen blanking
- ui/gtk: Draw guest frame at refresh cycle
- target/i386: fix size of EBP writeback in gen_enter()
- virtio-net: drop too short packets early
- target/ppc: Fix lxv/stxv MSR facility check
- target/ppc: Fix lxvx/stxvx facility check
- virtio-snd: add max size bounds check in input cb(CVE-2024-7730)

Signed-off-by: Jiabo Feng <fengjiabo1@huawei.com>
(cherry picked from commit e2eb79f1867bb8d8d870e758f06d2a32b3a4fc8a)
2024-11-07 09:49:22 +08:00

92 lines
3.0 KiB
Diff

From 5651eb5cfd3a49506be4be97f8def3fed713c641 Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@yandex-team.ru>
Date: Tue, 30 Apr 2024 13:53:33 +0300
Subject: [PATCH] virtio-net: drop too short packets early
Reproducer from https://gitlab.com/qemu-project/qemu/-/issues/1451
creates small packet (1 segment, len = 10 == n->guest_hdr_len),
then destroys queue.
"if (n->host_hdr_len != n->guest_hdr_len)" is triggered, if body creates
zero length/zero segment packet as there is nothing after guest header.
qemu_sendv_packet_async() tries to send it.
slirp discards it because it is smaller than Ethernet header,
but returns 0 because tx hooks are supposed to return total length of data.
0 is propagated upwards and is interpreted as "packet has been sent"
which is terrible because queue is being destroyed, nobody is waiting for TX
to complete and assert it triggered.
Fix is discard such empty packets instead of sending them.
Length 1 packets will go via different codepath:
virtqueue_push(q->tx_vq, elem, 0);
virtio_notify(vdev, q->tx_vq);
g_free(elem);
and aren't problematic.
Signed-off-by: Alexey Dobriyan <adobriyan@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit 2c3e4e2de699cd4d9f6c71f30a22d8f125cd6164)
Signed-off-by: zhujun2 <zhujun2_yewu@cmss.chinamobile.com>
---
hw/net/virtio-net.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 432c433540..b17137a686 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -2732,18 +2732,14 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
out_sg = elem->out_sg;
if (out_num < 1) {
virtio_error(vdev, "virtio-net header not in first element");
- virtqueue_detach_element(q->tx_vq, elem, 0);
- g_free(elem);
- return -EINVAL;
+ goto detach;
}
if (n->has_vnet_hdr) {
if (iov_to_buf(out_sg, out_num, 0, &vhdr, n->guest_hdr_len) <
n->guest_hdr_len) {
virtio_error(vdev, "virtio-net header incorrect");
- virtqueue_detach_element(q->tx_vq, elem, 0);
- g_free(elem);
- return -EINVAL;
+ goto detach;
}
if (n->needs_vnet_hdr_swap) {
virtio_net_hdr_swap(vdev, (void *) &vhdr);
@@ -2774,6 +2770,11 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
n->guest_hdr_len, -1);
out_num = sg_num;
out_sg = sg;
+
+ if (out_num < 1) {
+ virtio_error(vdev, "virtio-net nothing to send");
+ goto detach;
+ }
}
ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
@@ -2794,6 +2795,11 @@ drop:
}
}
return num_packets;
+
+detach:
+ virtqueue_detach_element(q->tx_vq, elem, 0);
+ g_free(elem);
+ return -EINVAL;
}
static void virtio_net_tx_timer(void *opaque);
--
2.41.0.windows.1