syzbot

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BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_disable_cb

write to 0xffff888102d86e78 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:2566
 skb_xmit_done+0x65/0x140 drivers/net/virtio_net.c:755
 vring_interrupt+0x152/0x180 drivers/virtio/virtio_ring.c:2715
 __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+0x1d0/0x5d0 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+0x60/0x100 arch/x86/kernel/irq.c:292
 common_interrupt+0x7e/0x90 arch/x86/kernel/irq.c:285
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
 kcsan_setup_watchpoint+0x415/0x430 kernel/kcsan/core.c:705
 check_access kernel/kcsan/core.c:753 [inline]
 __tsan_memcpy+0x3b4/0x3c0 kernel/kcsan/core.c:1365
 bpf_bprintf_prepare+0xae/0xd50 kernel/bpf/helpers.c:828
 ____bpf_trace_printk kernel/trace/bpf_trace.c:373 [inline]
 bpf_trace_printk+0x84/0x1c0 kernel/trace/bpf_trace.c:363
 bpf_prog_b3b54572e23ff2cd+0x39/0x3b
 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline]
 bpf_trace_run2+0x104/0x1c0 kernel/trace/bpf_trace.c:2404
 __traceiter_kfree+0x2b/0x50 include/trace/events/kmem.h:94
 __do_trace_kfree include/trace/events/kmem.h:94 [inline]
 trace_kfree include/trace/events/kmem.h:94 [inline]
 kfree+0x26f/0x310 mm/slub.c:4828
 simple_xattr_free fs/xattr.c:1213 [inline]
 simple_xattrs_free+0xbd/0x100 fs/xattr.c:1550
 shmem_evict_inode+0x42e/0x520 mm/shmem.c:1386
 evict+0x2e0/0x550 fs/inode.c:810
 iput_final fs/inode.c:1898 [inline]
 iput+0x447/0x5b0 fs/inode.c:1924
 do_unlinkat+0x2c4/0x4c0 fs/namei.c:4650
 __do_sys_unlink fs/namei.c:4689 [inline]
 __se_sys_unlink fs/namei.c:4687 [inline]
 __x64_sys_unlink+0x2e/0x40 fs/namei.c:4687
 x64_sys_call+0x22a6/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888102d86e78 of 2 bytes by task 3305 on cpu 1:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:873 [inline]
 virtqueue_disable_cb+0x58/0x150 drivers/virtio/virtio_ring.c:2566
 start_xmit+0x102/0x12a0 drivers/net/virtio_net.c:3298
 __netdev_start_xmit include/linux/netdevice.h:5204 [inline]
 netdev_start_xmit include/linux/netdevice.h:5213 [inline]
 xmit_one net/core/dev.c:3776 [inline]
 dev_hard_start_xmit+0x12c/0x3d0 net/core/dev.c:3792
 sch_direct_xmit+0x192/0x550 net/sched/sch_generic.c:343
 __dev_xmit_skb net/core/dev.c:4018 [inline]
 __dev_queue_xmit+0xe4f/0x1fb0 net/core/dev.c:4595
 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+0x77f/0x8b0 net/ipv4/ip_output.c:235
 __ip_finish_output net/ipv4/ip_output.c:-1 [inline]
 ip_finish_output+0x112/0x290 net/ipv4/ip_output.c:323
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip_output+0xad/0x170 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+0xb25/0xb40 net/ipv4/ip_output.c:527
 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:541
 __tcp_transmit_skb+0x1641/0x1a60 net/ipv4/tcp_output.c:1479
 __tcp_send_ack+0x227/0x350 net/ipv4/tcp_output.c:4280
 tcp_send_ack+0x29/0x30 net/ipv4/tcp_output.c:4286
 __tcp_cleanup_rbuf+0xd3/0x2c0 net/ipv4/tcp.c:1514
 tcp_cleanup_rbuf net/ipv4/tcp.c:1525 [inline]
 tcp_recvmsg_locked+0x1aec/0x1fd0 net/ipv4/tcp.c:2848
 tcp_recvmsg+0x12e/0x490 net/ipv4/tcp.c:2878
 inet_recvmsg+0xb7/0x290 net/ipv4/af_inet.c:883
 sock_recvmsg_nosec net/socket.c:1017 [inline]
 sock_recvmsg+0xf6/0x170 net/socket.c:1039
 sock_read_iter+0x152/0x1a0 net/socket.c:1109
 new_sync_read fs/read_write.c:489 [inline]
 vfs_read+0x5ca/0x6f0 fs/read_write.c:570
 ksys_read+0xda/0x1a0 fs/read_write.c:713
 __do_sys_read fs/read_write.c:722 [inline]
 __se_sys_read fs/read_write.c:720 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:720
 x64_sys_call+0x2d77/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 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: 3305 Comm: syz-executor Not tainted 6.15.0-rc5-syzkaller-00204-g0e1329d4045c #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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