syzbot

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BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

write to 0xffff8881023fa888 of 2 bytes by interrupt on cpu 1:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:1047 [inline]
 virtqueue_disable_cb+0x75/0x2c0 drivers/virtio/virtio_ring.c:3108
 skb_xmit_done+0x67/0x1a0 drivers/net/virtio_net.c:774
 vring_interrupt+0x2d7/0x310 drivers/virtio/virtio_ring.c:3254
 __handle_irq_event_percpu+0x8b/0x480 kernel/irq/handle.c:209
 handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
 handle_irq_event+0x64/0xf0 kernel/irq/handle.c:263
 handle_edge_irq+0x154/0x450 kernel/irq/chip.c:857
 generic_handle_irq_desc include/linux/irqdesc.h:186 [inline]
 handle_irq arch/x86/kernel/irq.c:262 [inline]
 call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
 __common_interrupt+0x60/0xb0 arch/x86/kernel/irq.c:333
 common_interrupt+0x7e/0x90 arch/x86/kernel/irq.c:326
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
 __sanitizer_cov_trace_const_cmp4+0x0/0x90 kernel/kcov.c:309
 fast_dput+0x40/0x2e0 fs/dcache.c:960
 dput+0x1f/0x50 fs/dcache.c:1040
 step_into_slowpath+0x196/0x4c0 fs/namei.c:2118
 step_into fs/namei.c:2152 [inline]
 walk_component fs/namei.c:2288 [inline]
 link_path_walk+0x947/0xdd0 fs/namei.c:-1
 path_lookupat+0x53/0x4c0 fs/namei.c:2812
 filename_lookup+0x18f/0x390 fs/namei.c:2842
 do_readlinkat+0x74/0x2f0 fs/stat.c:571
 __do_sys_readlink fs/stat.c:605 [inline]
 __se_sys_readlink fs/stat.c:602 [inline]
 __x64_sys_readlink+0x47/0x60 fs/stat.c:602
 x64_sys_call+0x2b51/0x3020 arch/x86/include/generated/asm/syscalls_64.h:90
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881023fa888 of 2 bytes by task 3287 on cpu 0:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:1046 [inline]
 virtqueue_disable_cb+0x4c/0x2c0 drivers/virtio/virtio_ring.c:3108
 start_xmit+0x107/0x1a80 drivers/net/virtio_net.c:3344
 __netdev_start_xmit include/linux/netdevice.h:5368 [inline]
 netdev_start_xmit include/linux/netdevice.h:5377 [inline]
 xmit_one net/core/dev.c:3888 [inline]
 dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3904
 sch_direct_xmit+0x199/0x580 net/sched/sch_generic.c:372
 __dev_xmit_skb net/core/dev.c:4209 [inline]
 __dev_queue_xmit+0xd81/0x1e60 net/core/dev.c:4831
 dev_queue_xmit include/linux/netdevice.h:3418 [inline]
 neigh_hh_output include/net/neighbour.h:544 [inline]
 neigh_output include/net/neighbour.h:558 [inline]
 ip_finish_output2+0x752/0x8a0 net/ipv4/ip_output.c:237
 __ip_finish_output net/ipv4/ip_output.c:-1 [inline]
 ip_finish_output+0x112/0x290 net/ipv4/ip_output.c:325
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0xbd/0x1c0 net/ipv4/ip_output.c:438
 dst_output include/net/dst.h:471 [inline]
 ip_local_out net/ipv4/ip_output.c:131 [inline]
 __ip_queue_xmit+0xb4c/0xb80 net/ipv4/ip_output.c:534
 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548
 __tcp_transmit_skb+0x1c4f/0x20f0 net/ipv4/tcp_output.c:1716
 tcp_transmit_skb net/ipv4/tcp_output.c:1733 [inline]
 tcp_write_xmit+0x17c0/0x3560 net/ipv4/tcp_output.c:3061
 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3244
 tcp_push_pending_frames include/net/tcp.h:2360 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:6075 [inline]
 tcp_rcv_established+0xd9e/0x1320 net/ipv4/tcp_input.c:6558
 tcp_v4_do_rcv+0x3b1/0xa20 net/ipv4/tcp_ipv4.c:1851
 sk_backlog_rcv include/net/sock.h:1192 [inline]
 __release_sock+0x146/0x2d0 net/core/sock.c:3225
 release_sock+0x125/0x180 net/core/sock.c:3824
 tcp_sendmsg+0x39/0x50 net/ipv4/tcp.c:1453
 inet_sendmsg+0x76/0xd0 net/ipv4/af_inet.c:866
 sock_sendmsg_nosec net/socket.c:776 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 sock_write_iter+0x2c7/0x320 net/socket.c:1243
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x57d/0x9b0 fs/read_write.c:687
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x27e1/0x3020 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000 -> 0x0001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3287 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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