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BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

write to 0xffff88810371ae88 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:856
 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
 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705
 memcmp+0x23/0x90 lib/string.c:683
 memcmp include/linux/fortify-string.h:725 [inline]
 namecmp fs/proc/proc_sysctl.c:107 [inline]
 insert_entry fs/proc/proc_sysctl.c:167 [inline]
 insert_header+0x6ac/0x970 fs/proc/proc_sysctl.c:252
 __register_sysctl_table+0xb69/0xc00 fs/proc/proc_sysctl.c:1399
 register_net_sysctl_sz+0x19f/0x1c0 net/sysctl_net.c:171
 __devinet_sysctl_register+0x1cd/0x260 net/ipv4/devinet.c:2712
 devinet_init_net+0x278/0x550 net/ipv4/devinet.c:2840
 ops_init+0x22a/0x2e0 net/core/net_namespace.c:137
 setup_net+0x9f/0x230 net/core/net_namespace.c:446
 copy_net_ns+0x310/0x450 net/core/net_namespace.c:579
 create_new_namespaces+0x20e/0x440 kernel/nsproxy.c:132
 copy_namespaces+0x1ad/0x210 kernel/nsproxy.c:195
 copy_process+0x10ae/0x23a0 kernel/fork.c:2265
 kernel_clone+0x1a5/0x5e0 kernel/fork.c:2723
 __do_sys_clone kernel/fork.c:2864 [inline]
 __se_sys_clone kernel/fork.c:2848 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2848
 x64_sys_call+0x1222/0x3020 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810371ae88 of 2 bytes by task 3280 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+0x107/0x1a60 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+0x12a/0x3a0 net/core/dev.c:3904
 sch_direct_xmit+0x192/0x550 net/sched/sch_generic.c:372
 __dev_xmit_skb net/core/dev.c:4209 [inline]
 __dev_queue_xmit+0xdb9/0x1ec0 net/core/dev.c:4831
 dev_queue_xmit include/linux/netdevice.h:3418 [inline]
 neigh_hh_output include/net/neighbour.h:540 [inline]
 neigh_output include/net/neighbour.h:554 [inline]
 ip_finish_output2+0x705/0x8c0 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:470 [inline]
 ip_local_out net/ipv4/ip_output.c:131 [inline]
 __ip_queue_xmit+0xb68/0xba0 net/ipv4/ip_output.c:534
 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548
 __tcp_transmit_skb+0x1c2a/0x20b0 net/ipv4/tcp_output.c:1715
 tcp_transmit_skb net/ipv4/tcp_output.c:1733 [inline]
 tcp_write_xmit+0x129e/0x36a0 net/ipv4/tcp_output.c:3060
 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3243
 tcp_push+0x311/0x330 net/ipv4/tcp.c:776
 tcp_sendmsg_locked+0x24bf/0x2cc0 net/ipv4/tcp.c:1418
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1455
 inet_sendmsg+0x76/0xd0 net/ipv4/af_inet.c:866
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 sock_write_iter+0x2c7/0x320 net/socket.c:1254
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x5a6/0x9f0 fs/read_write.c:688
 ksys_write+0xdc/0x1a0 fs/read_write.c:740
 __do_sys_write fs/read_write.c:751 [inline]
 __se_sys_write fs/read_write.c:748 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:748
 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+0x12c/0x3b0 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: 3280 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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