syzbot

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BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

read to 0xffff8881020b3078 of 2 bytes by task 3293 on cpu 1:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:873 [inline]
 virtqueue_disable_cb+0x58/0x150 drivers/virtio/virtio_ring.c:2570
 start_xmit+0x103/0x17a0 drivers/net/virtio_net.c:3362
 __netdev_start_xmit include/linux/netdevice.h:5222 [inline]
 netdev_start_xmit include/linux/netdevice.h:5231 [inline]
 xmit_one net/core/dev.c:3839 [inline]
 dev_hard_start_xmit+0x125/0x3e0 net/core/dev.c:3855
 sch_direct_xmit+0x192/0x550 net/sched/sch_generic.c:344
 __dev_xmit_skb net/core/dev.c:4114 [inline]
 __dev_queue_xmit+0xe9a/0x2000 net/core/dev.c:4691
 dev_queue_xmit include/linux/netdevice.h:3361 [inline]
 neigh_hh_output include/net/neighbour.h:531 [inline]
 neigh_output include/net/neighbour.h:545 [inline]
 ip_finish_output2+0x77f/0x8b0 net/ipv4/ip_output.c:235
 __ip_finish_output net/ipv4/ip_output.c:-1 [inline]
 ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:323
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0xbd/0x190 net/ipv4/ip_output.c:436
 dst_output include/net/dst.h:461 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0xb4b/0xb80 net/ipv4/ip_output.c:532
 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:546
 __tcp_transmit_skb+0x1641/0x1a60 net/ipv4/tcp_output.c:1479
 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline]
 tcp_write_xmit+0x1210/0x2fd0 net/ipv4/tcp_output.c:2833
 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3016
 tcp_push+0x311/0x330 net/ipv4/tcp.c:757
 tcp_sendmsg_locked+0x2458/0x2c00 net/ipv4/tcp.c:1356
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1393
 inet_sendmsg+0x76/0xd0 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x102/0x180 net/socket.c:729
 sock_write_iter+0x165/0x1b0 net/socket.c:1179
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x52a/0x960 fs/read_write.c:686
 ksys_write+0xda/0x1a0 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:746
 x64_sys_call+0x27fe/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff8881020b3078 of 2 bytes by interrupt on cpu 0:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:874 [inline]
 virtqueue_disable_cb+0x7a/0x150 drivers/virtio/virtio_ring.c:2570
 skb_xmit_done+0x65/0x140 drivers/net/virtio_net.c:784
 vring_interrupt+0x155/0x180 drivers/virtio/virtio_ring.c:2719
 __handle_irq_event_percpu+0x90/0x440 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0x64/0xf0 kernel/irq/handle.c:210
 handle_edge_irq+0x154/0x470 kernel/irq/chip.c:855
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:254 [inline]
 call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
 __common_interrupt+0x60/0xb0 arch/x86/kernel/irq.c:325
 common_interrupt+0x7e/0x90 arch/x86/kernel/irq.c:318
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
 memcpy_orig+0xc0/0x130 arch/x86/lib/memcpy_64.S:128
 __d_alloc+0x12c/0x340 fs/dcache.c:1722
 d_alloc+0x2e/0x100 fs/dcache.c:1769
 lookup_one_qstr_excl+0x99/0x250 fs/namei.c:1693
 filename_create+0x149/0x230 fs/namei.c:4140
 do_mkdirat+0x52/0x3f0 fs/namei.c:4391
 __do_sys_mkdirat fs/namei.c:4416 [inline]
 __se_sys_mkdirat fs/namei.c:4414 [inline]
 __x64_sys_mkdirat+0x4c/0x60 fs/namei.c:4414
 x64_sys_call+0x2b7/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:259
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 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: 3315 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
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