syzbot

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BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

write to 0xffff8881012e0c78 of 2 bytes by interrupt on cpu 1:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:874 [inline]
 virtqueue_disable_cb+0x85/0x180 drivers/virtio/virtio_ring.c:2566
 skb_xmit_done+0x5f/0x140 drivers/net/virtio_net.c:755
 vring_interrupt+0x164/0x190 drivers/virtio/virtio_ring.c:2715
 __handle_irq_event_percpu+0x97/0x490 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+0x16d/0x5b0 kernel/irq/chip.c:831
 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:266 [inline]
 __common_interrupt+0x58/0xe0 arch/x86/kernel/irq.c:292
 common_interrupt+0x3e/0x90 arch/x86/kernel/irq.c:285
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
 native_irq_enable arch/x86/include/asm/irqflags.h:-1 [inline]
 arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline]
 handle_softirqs+0x6f/0x280 kernel/softirq.c:563
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x3a/0xc0 kernel/softirq.c:680
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x73/0x80 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705
 should_fail_ex+0x31/0x270 lib/fault-inject.c:146
 should_fail+0xb/0x10 lib/fault-inject.c:184
 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:37
 _inline_copy_to_user include/linux/uaccess.h:193 [inline]
 _copy_to_user+0x20/0xa0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 xt_obj_to_user+0xa3/0x120 net/netfilter/x_tables.c:299
 xt_target_to_user+0x72/0x100 net/netfilter/x_tables.c:343
 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:859 [inline]
 get_entries net/ipv4/netfilter/ip_tables.c:1022 [inline]
 do_ipt_get_ctl+0xb69/0xc90 net/ipv4/netfilter/ip_tables.c:1668
 nf_getsockopt+0x18c/0x1b0 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x12e/0x170 net/ipv4/ip_sockglue.c:1777
 tcp_getsockopt+0xb4/0xe0 net/ipv4/tcp.c:4727
 sock_common_getsockopt+0x5b/0x70 net/core/sock.c:3867
 do_sock_getsockopt+0x1fc/0x290 net/socket.c:2357
 __sys_getsockopt net/socket.c:2386 [inline]
 __do_sys_getsockopt net/socket.c:2393 [inline]
 __se_sys_getsockopt net/socket.c:2390 [inline]
 __x64_sys_getsockopt+0x191/0x210 net/socket.c:2390
 x64_sys_call+0x128f/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:56
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881012e0c78 of 2 bytes by task 3291 on cpu 0:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:873 [inline]
 virtqueue_disable_cb+0x63/0x180 drivers/virtio/virtio_ring.c:2566
 start_xmit+0x12c/0x1480 drivers/net/virtio_net.c:3298
 __netdev_start_xmit include/linux/netdevice.h:5203 [inline]
 netdev_start_xmit include/linux/netdevice.h:5212 [inline]
 xmit_one net/core/dev.c:3774 [inline]
 dev_hard_start_xmit+0x12e/0x400 net/core/dev.c:3790
 sch_direct_xmit+0x1ab/0x590 net/sched/sch_generic.c:343
 __dev_xmit_skb net/core/dev.c:4016 [inline]
 __dev_queue_xmit+0xf7a/0x20b0 net/core/dev.c:4593
 dev_queue_xmit include/linux/netdevice.h:3350 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip_finish_output2+0x740/0x8b0 net/ipv4/ip_output.c:235
 __ip_finish_output net/ipv4/ip_output.c:-1 [inline]
 ip_finish_output+0x11d/0x2a0 net/ipv4/ip_output.c:323
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip_output+0xb7/0x190 net/ipv4/ip_output.c:433
 dst_output include/net/dst.h:459 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0xb32/0xb50 net/ipv4/ip_output.c:527
 ip_queue_xmit+0x38/0x50 net/ipv4/ip_output.c:541
 __tcp_transmit_skb+0x160a/0x1a20 net/ipv4/tcp_output.c:1479
 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline]
 tcp_write_xmit+0x121e/0x3030 net/ipv4/tcp_output.c:2839
 __tcp_push_pending_frames+0x6c/0x1a0 net/ipv4/tcp_output.c:3022
 tcp_push+0x2f6/0x310 net/ipv4/tcp.c:759
 tcp_sendmsg_locked+0x224c/0x2760 net/ipv4/tcp.c:1334
 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1366
 inet_sendmsg+0x77/0xd0 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x102/0x180 net/socket.c:727
 sock_write_iter+0x186/0x1c0 net/socket.c:1131
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x79b/0x950 fs/read_write.c:684
 ksys_write+0xeb/0x1b0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:747 [inline]
 __se_sys_write fs/read_write.c:744 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:744
 x64_sys_call+0x2a45/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 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: 3291 Comm: syz-executor Not tainted 6.15.0-rc2-syzkaller-00042-g1a1d569a75f3 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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