syzbot

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BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

read to 0xffff8881026c9288 of 2 bytes by interrupt 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
 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
 check_access kernel/kcsan/core.c:787 [inline]
 __kcsan_check_access+0x1a7/0x1d0 kernel/kcsan/core.c:958
 instrument_read_write include/linux/instrumented.h:56 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:159 [inline]
 _raw_spin_lock+0x4a/0xa0 kernel/locking/spinlock.c:158
 spin_lock include/linux/spinlock.h:342 [inline]
 filemap_remove_folio+0x57/0x1d0 mm/filemap.c:255
 truncate_inode_folio+0x42/0x50 mm/truncate.c:176
 shmem_undo_range+0x26d/0xb10 mm/shmem.c:1145
 shmem_truncate_range mm/shmem.c:1277 [inline]
 shmem_evict_inode+0x12e/0x540 mm/shmem.c:1407
 evict+0x2af/0x510 fs/inode.c:841
 iput_final fs/inode.c:1960 [inline]
 iput+0x41a/0x580 fs/inode.c:2009
 filename_unlinkat+0x21f/0x410 fs/namei.c:5572
 __do_sys_unlink fs/namei.c:5603 [inline]
 __se_sys_unlink+0x2b/0xe0 fs/namei.c:5600
 __x64_sys_unlink+0x1f/0x30 fs/namei.c:5600
 x64_sys_call+0x2eb6/0x3020 arch/x86/include/generated/asm/syscalls_64.h:88
 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

write to 0xffff8881026c9288 of 2 bytes by task 3300 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
 start_xmit+0x107/0x1a60 drivers/net/virtio_net.c:3344
 __netdev_start_xmit include/linux/netdevice.h:5343 [inline]
 netdev_start_xmit include/linux/netdevice.h:5352 [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:3401 [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+0x1c1c/0x20a0 net/ipv4/tcp_output.c:1713
 __tcp_send_ack+0x288/0x3b0 net/ipv4/tcp_output.c:4497
 tcp_send_ack+0x29/0x30 net/ipv4/tcp_output.c:4503
 __tcp_cleanup_rbuf+0x15a/0x290 net/ipv4/tcp.c:1603
 tcp_cleanup_rbuf net/ipv4/tcp.c:1615 [inline]
 tcp_recvmsg_locked+0x1c41/0x2160 net/ipv4/tcp.c:2919
 tcp_recvmsg+0x12a/0x460 net/ipv4/tcp.c:2948
 inet_recvmsg+0x8d/0x210 net/ipv4/af_inet.c:896
 sock_recvmsg_nosec net/socket.c:1137 [inline]
 sock_recvmsg+0xda/0x120 net/socket.c:1159
 sock_read_iter+0x169/0x1b0 net/socket.c:1229
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x6c0/0x7f0 fs/read_write.c:574
 ksys_read+0xdc/0x1a0 fs/read_write.c:717
 __do_sys_read fs/read_write.c:726 [inline]
 __se_sys_read fs/read_write.c:724 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:724
 x64_sys_call+0x2886/0x3020 arch/x86/include/generated/asm/syscalls_64.h:1
 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: 1 UID: 0 PID: 3300 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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