syzbot

==================================================================
BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

read to 0xffff888101697f78 of 2 bytes by interrupt on cpu 1:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:877 [inline]
 virtqueue_disable_cb+0x58/0x150 drivers/virtio/virtio_ring.c:2569
 skb_xmit_done+0x65/0x140 drivers/net/virtio_net.c:784
 vring_interrupt+0x155/0x180 drivers/virtio/virtio_ring.c:2718
 __handle_irq_event_percpu+0x9d/0x540 kernel/irq/handle.c:203
 handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
 handle_irq_event+0x64/0xf0 kernel/irq/handle.c:257
 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:688
 kcsan_setup_watchpoint+0x415/0x430 kernel/kcsan/core.c:705
 folios_put_refs+0x1ee/0x2d0 mm/swap.c:957
 free_pages_and_swap_cache+0x278/0x400 mm/swap_state.c:355
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
 tlb_flush_mmu+0x2dc/0x450 mm/mmu_gather.c:404
 zap_pte_range mm/memory.c:1894 [inline]
 zap_pmd_range mm/memory.c:1947 [inline]
 zap_pud_range mm/memory.c:1976 [inline]
 zap_p4d_range mm/memory.c:1997 [inline]
 unmap_page_range+0x22c8/0x25c0 mm/memory.c:2018
 unmap_single_vma mm/memory.c:2061 [inline]
 unmap_vmas+0x23d/0x3a0 mm/memory.c:2105
 exit_mmap+0x1b0/0x6c0 mm/mmap.c:1280
 __mmput+0x28/0x1c0 kernel/fork.c:1133
 mmput+0x40/0x50 kernel/fork.c:1156
 exit_mm+0xe4/0x180 kernel/exit.c:582
 do_exit+0x417/0x15c0 kernel/exit.c:954
 do_group_exit+0xff/0x140 kernel/exit.c:1107
 get_signal+0xe58/0xf70 kernel/signal.c:3034
 arch_do_signal_or_restart+0x96/0x440 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x77/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff888101697f78 of 2 bytes by task 3304 on cpu 0:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:878 [inline]
 virtqueue_disable_cb+0x7a/0x150 drivers/virtio/virtio_ring.c:2569
 start_xmit+0x10e/0x17a0 drivers/net/virtio_net.c:3382
 __netdev_start_xmit include/linux/netdevice.h:5248 [inline]
 netdev_start_xmit include/linux/netdevice.h:5257 [inline]
 xmit_one net/core/dev.c:3845 [inline]
 dev_hard_start_xmit+0x125/0x3e0 net/core/dev.c:3861
 sch_direct_xmit+0x192/0x550 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4152 [inline]
 __dev_queue_xmit+0xe9a/0x2000 net/core/dev.c:4729
 dev_queue_xmit include/linux/netdevice.h:3365 [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:237
 __ip_finish_output net/ipv4/ip_output.c:-1 [inline]
 ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:325
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0xbd/0x190 net/ipv4/ip_output.c:438
 dst_output include/net/dst.h:464 [inline]
 ip_local_out net/ipv4/ip_output.c:131 [inline]
 __ip_queue_xmit+0xbbf/0xc00 net/ipv4/ip_output.c:534
 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548
 __tcp_transmit_skb+0x17fd/0x1c10 net/ipv4/tcp_output.c:1628
 tcp_transmit_skb net/ipv4/tcp_output.c:1646 [inline]
 tcp_write_xmit+0x129c/0x30f0 net/ipv4/tcp_output.c:2999
 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3182
 tcp_push+0x311/0x330 net/ipv4/tcp.c:777
 tcp_sendmsg_locked+0x2458/0x2c00 net/ipv4/tcp.c:1376
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1413
 inet_sendmsg+0x76/0xd0 net/ipv4/af_inet.c:853
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x102/0x180 net/socket.c:742
 sock_write_iter+0x1a7/0x1f0 net/socket.c:1195
 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+0x2802/0x3000 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

value changed: 0x0000 -> 0x0001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3304 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================