================================================================== BUG: KCSAN: data-race in queue_access_lock / snd_seq_check_queue read to 0xffff888100e77ea4 of 1 bytes by interrupt on cpu 0: snd_seq_check_queue+0x59/0x200 sound/core/seq/seq_queue.c:247 snd_seq_timer_interrupt+0x243/0x280 sound/core/seq/seq_timer.c:158 snd_timer_process_callbacks+0x1e4/0x220 sound/core/timer.c:757 snd_timer_interrupt sound/core/timer.c:880 [inline] snd_timer_interrupt+0x483/0x930 sound/core/timer.c:801 snd_hrtimer_callback+0x18f/0x260 sound/core/hrtimer.c:50 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 is_atomic kernel/kcsan/core.c:143 [inline] should_watch kernel/kcsan/core.c:162 [inline] check_access kernel/kcsan/core.c:408 [inline] __tsan_read4+0xc7/0x1f0 kernel/kcsan/core.c:529 skb_zcopy include/linux/skbuff.h:1412 [inline] skb_orphan_frags_rx include/linux/skbuff.h:2735 [inline] deliver_skb net/core/dev.c:1885 [inline] __netif_receive_skb_core+0x11bd/0x1a90 net/core/dev.c:4787 __netif_receive_skb_one_core+0x67/0xe0 net/core/dev.c:4927 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5043 process_backlog+0x207/0x4b0 net/core/dev.c:5874 napi_poll net/core/dev.c:6311 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6379 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] enqueue_to_backlog+0x354/0x740 net/core/dev.c:4195 netif_rx_internal+0x7e/0x2b0 net/core/dev.c:4444 netif_rx_ni+0x4e/0x290 net/core/dev.c:4485 dev_loopback_xmit+0x192/0x250 net/core/dev.c:3507 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_finish_output2+0xbc7/0xec0 net/ipv6/ip6_output.c:80 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795 ip6_push_pending_frames+0x9d/0xc0 net/ipv6/ip6_output.c:1815 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline] rawv6_sendmsg+0x1d22/0x21e0 net/ipv6/raw.c:956 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311 __sys_sendmmsg+0x123/0x350 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff888100e77ea4 of 1 bytes by task 28700 on cpu 1: queue_access_lock+0x89/0xc0 sound/core/seq/seq_queue.c:356 snd_seq_control_queue+0x77/0x350 sound/core/seq/seq_queue.c:719 event_input_timer+0x2f/0x50 sound/core/seq/seq_system.c:103 snd_seq_deliver_single_event.constprop.0+0x3e8/0x4d0 sound/core/seq/seq_clientmgr.c:638 snd_seq_deliver_event+0x2e9/0x4c0 sound/core/seq/seq_clientmgr.c:839 snd_seq_dispatch_event+0xa1/0x340 sound/core/seq/seq_clientmgr.c:913 snd_seq_check_queue+0xeb/0x200 sound/core/seq/seq_queue.c:262 snd_seq_enqueue_event+0x163/0x2b0 sound/core/seq/seq_queue.c:330 snd_seq_client_enqueue_event.constprop.0+0x187/0x2a0 sound/core/seq/seq_clientmgr.c:974 snd_seq_write+0x23f/0x4d0 sound/core/seq/seq_clientmgr.c:1093 __vfs_write+0x67/0xc0 fs/read_write.c:494 vfs_write fs/read_write.c:558 [inline] vfs_write+0x18a/0x390 fs/read_write.c:542 ksys_write+0x17b/0x1b0 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x4c/0x60 fs/read_write.c:620 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 28700 Comm: syz-executor.0 Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================