syzbot

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BUG: KCSAN: data-race in virtqueue_get_buf_ctx / vring_interrupt

read-write to 0xffff888103674948 of 2 bytes by task 1807 on cpu 1:
 virtqueue_get_buf_ctx_split drivers/virtio/virtio_ring.c:783 [inline]
 virtqueue_get_buf_ctx+0x3a2/0x570 drivers/virtio/virtio_ring.c:2004
 virtqueue_get_buf+0x1b/0x20 drivers/virtio/virtio_ring.c:2010
 free_old_xmit_skbs+0x50/0x180 drivers/net/virtio_net.c:1554
 start_xmit+0xdb/0xaf0 drivers/net/virtio_net.c:1786
 __netdev_start_xmit include/linux/netdevice.h:4805 [inline]
 netdev_start_xmit include/linux/netdevice.h:4819 [inline]
 xmit_one+0xc0/0x2a0 net/core/dev.c:3590
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606
 sch_direct_xmit+0x1ac/0x580 net/sched/sch_generic.c:342
 __dev_xmit_skb+0x800/0xdb0 net/core/dev.c:3817
 __dev_queue_xmit+0x59f/0xfe0 net/core/dev.c:4221
 dev_queue_xmit include/linux/netdevice.h:2994 [inline]
 neigh_hh_output include/net/neighbour.h:533 [inline]
 neigh_output include/net/neighbour.h:547 [inline]
 ip_finish_output2+0x70b/0x850 net/ipv4/ip_output.c:228
 ip_finish_output+0xf3/0x250 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:451 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 __ip_queue_xmit+0xa2e/0xa50 net/ipv4/ip_output.c:532
 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:546
 __tcp_transmit_skb+0x12a4/0x1790 net/ipv4/tcp_output.c:1405
 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline]
 tcp_write_xmit+0x13c8/0x30d0 net/ipv4/tcp_output.c:2693
 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2877
 tcp_push+0x300/0x310 net/ipv4/tcp.c:726
 tcp_sendmsg_locked+0x1bbb/0x1fd0 net/ipv4/tcp.c:1420
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1448
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 sock_write_iter+0x1a3/0x200 net/socket.c:1108
 call_write_iter include/linux/fs.h:2058 [inline]
 new_sync_write fs/read_write.c:504 [inline]
 vfs_write+0x71c/0x890 fs/read_write.c:591
 ksys_write+0xe8/0x1a0 fs/read_write.c:644
 __do_sys_write fs/read_write.c:656 [inline]
 __se_sys_write fs/read_write.c:653 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:653
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff888103674948 of 2 bytes by interrupt on cpu 0:
 more_used_split drivers/virtio/virtio_ring.c:736 [inline]
 more_used drivers/virtio/virtio_ring.c:2148 [inline]
 vring_interrupt+0x99/0x170 drivers/virtio/virtio_ring.c:2155
 __handle_irq_event_percpu+0x92/0x400 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0x60/0xf0 kernel/irq/handle.c:210
 handle_edge_irq+0x17e/0x5a0 kernel/irq/chip.c:817
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq arch/x86/kernel/irq.c:231 [inline]
 __common_interrupt+0x60/0x100 arch/x86/kernel/irq.c:250
 common_interrupt+0x45/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x27/0x40

value changed: 0x5a25 -> 0x5a26

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10444 Comm: syz-executor.5 Not tainted 5.19.0-rc5-syzkaller-00228-ge5524c2a1fc4-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
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