syzbot


KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event

Status: moderation: reported on 2025/07/05 04:29
Subsystems: pm
[Documentation on labels]
Reported-by: syzbot+f1c34e6db0a3f2b2b1d9@syzkaller.appspotmail.com
First crash: 10d, last: 3d21h

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event

write to 0xffff888131d9b238 of 1 bytes by interrupt on cpu 0:
 wakeup_source_activate drivers/base/power/wakeup.c:565 [inline]
 wakeup_source_report_event+0xd6/0x280 drivers/base/power/wakeup.c:590
 __pm_stay_awake+0x34/0x70 drivers/base/power/wakeup.c:611
 ep_pm_stay_awake_rcu fs/eventpoll.c:727 [inline]
 ep_poll_callback+0x1f6/0x550 fs/eventpoll.c:1241
 __wake_up_common kernel/sched/wait.c:89 [inline]
 __wake_up_common_lock kernel/sched/wait.c:106 [inline]
 __wake_up+0x66/0xb0 kernel/sched/wait.c:127
 ep_poll_safewake fs/eventpoll.c:661 [inline]
 ep_poll_callback+0x3d6/0x550 fs/eventpoll.c:1271
 __wake_up_common kernel/sched/wait.c:89 [inline]
 __wake_up_common_lock kernel/sched/wait.c:106 [inline]
 __wake_up+0x66/0xb0 kernel/sched/wait.c:127
 bpf_ringbuf_notify+0x22/0x30 kernel/bpf/ringbuf.c:155
 irq_work_single kernel/irq_work.c:221 [inline]
 irq_work_run_list kernel/irq_work.c:252 [inline]
 irq_work_run+0xe2/0x2d0 kernel/irq_work.c:261
 __sysvec_irq_work+0x22/0x170 arch/x86/kernel/irq_work.c:22
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x66/0x80 arch/x86/kernel/irq_work.c:17
 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738
 __wrmsrq arch/x86/include/asm/msr.h:80 [inline]
 native_write_msr arch/x86/include/asm/msr.h:137 [inline]
 wrmsrq arch/x86/include/asm/msr.h:199 [inline]
 native_apic_msr_write+0x3d/0x60 arch/x86/include/asm/apic.h:212
 apic_write arch/x86/include/asm/apic.h:405 [inline]
 x2apic_send_IPI_self+0x10/0x20 arch/x86/kernel/apic/x2apic_phys.c:107
 __apic_send_IPI_self arch/x86/include/asm/apic.h:455 [inline]
 arch_irq_work_raise+0x46/0x50 arch/x86/kernel/irq_work.c:31
 irq_work_raise kernel/irq_work.c:84 [inline]
 __irq_work_queue_local+0x10f/0x2c0 kernel/irq_work.c:112
 irq_work_queue+0x70/0x100 kernel/irq_work.c:124
 bpf_ringbuf_commit kernel/bpf/ringbuf.c:-1 [inline]
 ____bpf_ringbuf_discard kernel/bpf/ringbuf.c:525 [inline]
 bpf_ringbuf_discard+0xd3/0xf0 kernel/bpf/ringbuf.c:523
 bpf_prog_fe0ed97373b08409+0x4b/0x4f
 bpf_dispatcher_nop_func include/linux/bpf.h:1322 [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:2258 [inline]
 bpf_trace_run3+0x10f/0x1d0 kernel/trace/bpf_trace.c:2300
 __do_trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x257/0x300 mm/slub.c:4744
 mt_free_rcu+0x2c/0x40 lib/maple_tree.c:198
 rcu_do_batch kernel/rcu/tree.c:2576 [inline]
 rcu_core+0x5a5/0xc00 kernel/rcu/tree.c:2832
 rcu_core_si+0xd/0x20 kernel/rcu/tree.c:2849
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:164
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888131d9b238 of 1 bytes by task 23817 on cpu 1:
 __ep_eventpoll_poll+0x1de/0x4e0 fs/eventpoll.c:956
 ep_eventpoll_poll+0x1f/0x30 fs/eventpoll.c:1030
 vfs_poll include/linux/poll.h:82 [inline]
 select_poll_one fs/select.c:480 [inline]
 do_select+0x8ee/0xf50 fs/select.c:536
 core_sys_select+0x3d7/0x6e0 fs/select.c:677
 do_pselect fs/select.c:759 [inline]
 __do_sys_pselect6 fs/select.c:802 [inline]
 __se_sys_pselect6+0x216/0x280 fs/select.c:793
 __x64_sys_pselect6+0x78/0x90 fs/select.c:793
 x64_sys_call+0x1caa/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:271
 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: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23817 Comm: syz.3.7029 Tainted: G        W           6.16.0-rc5-syzkaller-00193-g40f92e79b0aa #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/11 19:34 upstream 40f92e79b0aa 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/10 19:40 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/10 17:42 upstream 8c2e52ebbe88 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/10 03:39 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/10 03:38 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/09 23:41 upstream 8c2e52ebbe88 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/09 09:01 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/09 07:05 upstream 733923397fd9 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/08 19:02 upstream d006330be3f7 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/08 19:01 upstream d006330be3f7 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/08 19:00 upstream d006330be3f7 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/08 15:37 upstream d7b8f8e20813 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/07 00:35 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/07 00:35 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/07 00:35 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/06 11:20 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/06 11:20 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/05 21:45 upstream 05df91921da6 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/05 07:17 upstream a79a588fc176 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/05 07:16 upstream a79a588fc176 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
2025/07/05 04:29 upstream a79a588fc176 d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __ep_eventpoll_poll / wakeup_source_report_event
* Struck through repros no longer work on HEAD.