kernel/linux.git/drivers/net/virtio_net.c, branch v5.10.264

virtio_net: disable cb when NAPI is busy-polled

2026-07-24T13:49:05+00:00

[ Upstream commit 1eb8fc67ca41db71c90866ff76c990d85247daef ] When busy-poll is active, napi_schedule_prep() returns false in virtqueue_napi_schedule(), so virtqueue_disable_cb() is skipped. The device may keep firing irqs until reaches virtqueue_napi_complete(). Under load (received == budget), it will lead to a large number of spurious interrupts. Fix it by disabling the callback at the virtnet_poll() entry. This keeps the callback off while we poll and it is re-enabled by virtqueue_napi_complete() when going idle. Fixes: ceef438d613f ("virtio_net: remove custom busy_poll") Acked-by: Michael S. Tsirkin Signed-off-by: Longjun Tang Link: https://patch.msgid.link/20260629024230.37325-1-lange_tang@163.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

virtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false

2026-04-18T08:31:07+00:00

commit ba8bda9a0896746053aa97ac6c3e08168729172c upstream. A UAF issue occurs when the virtio_net driver is configured with napi_tx=N and the device's IFF_XMIT_DST_RELEASE flag is cleared (e.g., during the configuration of tc route filter rules). When IFF_XMIT_DST_RELEASE is removed from the net_device, the network stack expects the driver to hold the reference to skb->dst until the packet is fully transmitted and freed. In virtio_net with napi_tx=N, skbs may remain in the virtio transmit ring for an extended period. If the network namespace is destroyed while these skbs are still pending, the corresponding dst_ops structure has freed. When a subsequent packet is transmitted, free_old_xmit() is triggered to clean up old skbs. It then calls dst_release() on the skb associated with the stale dst_entry. Since the dst_ops (referenced by the dst_entry) has already been freed, a UAF kernel paging request occurs. fix it by adds skb_dst_drop(skb) in start_xmit to explicitly release the dst reference before the skb is queued in virtio_net. Call Trace: Unable to handle kernel paging request at virtual address ffff80007e150000 CPU: 2 UID: 0 PID: 6236 Comm: ping Kdump: loaded Not tainted 7.0.0-rc1+ #6 PREEMPT ... percpu_counter_add_batch+0x3c/0x158 lib/percpu_counter.c:98 (P) dst_release+0xe0/0x110 net/core/dst.c:177 skb_release_head_state+0xe8/0x108 net/core/skbuff.c:1177 sk_skb_reason_drop+0x54/0x2d8 net/core/skbuff.c:1255 dev_kfree_skb_any_reason+0x64/0x78 net/core/dev.c:3469 napi_consume_skb+0x1c4/0x3a0 net/core/skbuff.c:1527 __free_old_xmit+0x164/0x230 drivers/net/virtio_net.c:611 [virtio_net] free_old_xmit drivers/net/virtio_net.c:1081 [virtio_net] start_xmit+0x7c/0x530 drivers/net/virtio_net.c:3329 [virtio_net] ... Reproduction Steps: NETDEV="enp3s0" config_qdisc_route_filter() { tc qdisc del dev $NETDEV root tc qdisc add dev $NETDEV root handle 1: prio tc filter add dev $NETDEV parent 1:0 \ protocol ip prio 100 route to 100 flowid 1:1 ip route add 192.168.1.100/32 dev $NETDEV realm 100 } test_ns() { ip netns add testns ip link set $NETDEV netns testns ip netns exec testns ifconfig $NETDEV 10.0.32.46/24 ip netns exec testns ping -c 1 10.0.32.1 ip netns del testns } config_qdisc_route_filter test_ns sleep 2 test_ns Fixes: f2fc6a54585a ("[NETNS][IPV6] route6 - move ip6_dst_ops inside the network namespace") Cc: stable@vger.kernel.org Signed-off-by: xietangxin Reviewed-by: Xuan Zhuo Fixes: 0287587884b1 ("net: better IFF_XMIT_DST_RELEASE support") Link: https://patch.msgid.link/20260312025406.15641-1-xietangxin@yeah.net Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

virtio-net: ensure the received length does not exceed allocated size

2025-08-28T14:22:29+00:00

commit 315dbdd7cdf6aa533829774caaf4d25f1fd20e73 upstream. In xdp_linearize_page, when reading the following buffers from the ring, we forget to check the received length with the true allocate size. This can lead to an out-of-bound read. This commit adds that missing check. Cc: Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set") Signed-off-by: Bui Quang Minh Acked-by: Jason Wang Link: https://patch.msgid.link/20250630144212.48471-2-minhquangbui99@gmail.com Signed-off-by: Paolo Abeni [ adapted virtqueue_get_buf() to virtqueue_get_buf_ctx() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

virtio_net: Fix napi_skb_cache_put warning

2024-09-12T09:06:42+00:00

commit f8321fa75102246d7415a6af441872f6637c93ab upstream. After the commit bdacf3e34945 ("net: Use nested-BH locking for napi_alloc_cache.") was merged, the following warning began to appear: WARNING: CPU: 5 PID: 1 at net/core/skbuff.c:1451 napi_skb_cache_put+0x82/0x4b0 __warn+0x12f/0x340 napi_skb_cache_put+0x82/0x4b0 napi_skb_cache_put+0x82/0x4b0 report_bug+0x165/0x370 handle_bug+0x3d/0x80 exc_invalid_op+0x1a/0x50 asm_exc_invalid_op+0x1a/0x20 __free_old_xmit+0x1c8/0x510 napi_skb_cache_put+0x82/0x4b0 __free_old_xmit+0x1c8/0x510 __free_old_xmit+0x1c8/0x510 __pfx___free_old_xmit+0x10/0x10 The issue arises because virtio is assuming it's running in NAPI context even when it's not, such as in the netpoll case. To resolve this, modify virtnet_poll_tx() to only set NAPI when budget is available. Same for virtnet_poll_cleantx(), which always assumed that it was in a NAPI context. Fixes: df133f3f9625 ("virtio_net: bulk free tx skbs") Suggested-by: Jakub Kicinski Signed-off-by: Breno Leitao Reviewed-by: Jakub Kicinski Acked-by: Michael S. Tsirkin Acked-by: Jason Wang Reviewed-by: Heng Qi Link: https://patch.msgid.link/20240712115325.54175-1-leitao@debian.org Signed-off-by: Jakub Kicinski [Shivani: Modified to apply on v4.19.y-v5.10.y] Signed-off-by: Shivani Agarwal Signed-off-by: Greg Kroah-Hartman

virtio_net: checksum offloading handling fix

2024-07-05T07:12:39+00:00

[ Upstream commit 604141c036e1b636e2a71cf6e1aa09d1e45f40c2 ] In virtio spec 0.95, VIRTIO_NET_F_GUEST_CSUM was designed to handle partially checksummed packets, and the validation of fully checksummed packets by the device is independent of VIRTIO_NET_F_GUEST_CSUM negotiation. However, the specification erroneously stated: "If VIRTIO_NET_F_GUEST_CSUM is not negotiated, the device MUST set flags to zero and SHOULD supply a fully checksummed packet to the driver." This statement is inaccurate because even without VIRTIO_NET_F_GUEST_CSUM negotiation, the device can still set the VIRTIO_NET_HDR_F_DATA_VALID flag. Essentially, the device can facilitate the validation of these packets' checksums - a process known as RX checksum offloading - removing the need for the driver to do so. This scenario is currently not implemented in the driver and requires correction. The necessary specification correction[1] has been made and approved in the virtio TC vote. [1] https://lists.oasis-open.org/archives/virtio-comment/202401/msg00011.html Fixes: 4f49129be6fa ("virtio-net: Set RXCSUM feature if GUEST_CSUM is available") Signed-off-by: Heng Qi Reviewed-by: Jiri Pirko Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

virtio_net: Fix "‘%d’ directive writing between 1 and 11 bytes into a region of size 10" warnings

2024-02-23T07:42:14+00:00

[ Upstream commit e3fe8d28c67bf6c291e920c6d04fa22afa14e6e4 ] Fix the warnings when building virtio_net driver. " drivers/net/virtio_net.c: In function ‘init_vqs’: drivers/net/virtio_net.c:4551:48: warning: ‘%d’ directive writing between 1 and 11 bytes into a region of size 10 [-Wformat-overflow=] 4551 | sprintf(vi->rq[i].name, "input.%d", i); | ^~ In function ‘virtnet_find_vqs’, inlined from ‘init_vqs’ at drivers/net/virtio_net.c:4645:8: drivers/net/virtio_net.c:4551:41: note: directive argument in the range [-2147483643, 65534] 4551 | sprintf(vi->rq[i].name, "input.%d", i); | ^~~~~~~~~~ drivers/net/virtio_net.c:4551:17: note: ‘sprintf’ output between 8 and 18 bytes into a destination of size 16 4551 | sprintf(vi->rq[i].name, "input.%d", i); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/virtio_net.c: In function ‘init_vqs’: drivers/net/virtio_net.c:4552:49: warning: ‘%d’ directive writing between 1 and 11 bytes into a region of size 9 [-Wformat-overflow=] 4552 | sprintf(vi->sq[i].name, "output.%d", i); | ^~ In function ‘virtnet_find_vqs’, inlined from ‘init_vqs’ at drivers/net/virtio_net.c:4645:8: drivers/net/virtio_net.c:4552:41: note: directive argument in the range [-2147483643, 65534] 4552 | sprintf(vi->sq[i].name, "output.%d", i); | ^~~~~~~~~~~ drivers/net/virtio_net.c:4552:17: note: ‘sprintf’ output between 9 and 19 bytes into a destination of size 16 4552 | sprintf(vi->sq[i].name, "output.%d", i); " Reviewed-by: Xuan Zhuo Signed-off-by: Zhu Yanjun Link: https://lore.kernel.org/r/20240104020902.2753599-1-yanjun.zhu@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

virtio-net: set queues after driver_ok

2023-08-26T13:26:56+00:00

commit 51b813176f098ff61bd2833f627f5319ead098a5 upstream. Commit 25266128fe16 ("virtio-net: fix race between set queues and probe") tries to fix the race between set queues and probe by calling _virtnet_set_queues() before DRIVER_OK is set. This violates virtio spec. Fixing this by setting queues after virtio_device_ready(). Note that rtnl needs to be held for userspace requests to change the number of queues. So we are serialized in this way. Fixes: 25266128fe16 ("virtio-net: fix race between set queues and probe") Reported-by: Dragos Tatulea Acked-by: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

virtio-net: fix race between set queues and probe

2023-08-11T09:57:43+00:00

commit 25266128fe16d5632d43ada34c847d7b8daba539 upstream. A race were found where set_channels could be called after registering but before virtnet_set_queues() in virtnet_probe(). Fixing this by moving the virtnet_set_queues() before netdevice registering. While at it, use _virtnet_set_queues() to avoid holding rtnl as the device is not even registered at that time. Cc: stable@vger.kernel.org Fixes: a220871be66f ("virtio-net: correctly enable multiqueue") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Reviewed-by: Xuan Zhuo Link: https://lore.kernel.org/r/20230725072049.617289-1-jasowang@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

virtio_net: suppress cpu stall when free_unused_bufs

2023-05-17T09:48:12+00:00

[ Upstream commit f8bb5104394560e29017c25bcade4c6b7aabd108 ] For multi-queue and large ring-size use case, the following error occurred when free_unused_bufs: rcu: INFO: rcu_sched self-detected stall on CPU. Fixes: 986a4f4d452d ("virtio_net: multiqueue support") Signed-off-by: Wenliang Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

virtio_net: split free_unused_bufs()

2023-05-17T09:48:12+00:00

[ Upstream commit 6e345f8c7cd029ad3aaece15ad4425ac26e4eb63 ] This patch separates two functions for freeing sq buf and rq buf from free_unused_bufs(). When supporting the enable/disable tx/rq queue in the future, it is necessary to support separate recovery of a sq buf or a rq buf. Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Message-Id: <20220801063902.129329-40-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin Stable-dep-of: f8bb51043945 ("virtio_net: suppress cpu stall when free_unused_bufs") Signed-off-by: Sasha Levin