================================================================== BUG: KCSAN: data-race in fasync_remove_entry / kill_fasync write to 0xffff888098db82f8 of 8 bytes by task 17039 on cpu 1: fasync_remove_entry+0xba/0x120 fs/fcntl.c:882 fasync_helper+0xcf/0xdc fs/fcntl.c:981 perf_fasync+0x6c/0xa0 kernel/events/core.c:5917 __fput+0x46a/0x520 fs/file_table.c:277 ____fput+0x1f/0x30 fs/file_table.c:313 task_work_run+0xf6/0x130 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x353/0x370 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888098db82f8 of 8 bytes by interrupt on cpu 0: kill_fasync+0x3f/0x180 fs/fcntl.c:1019 perf_event_wakeup+0x11f/0x160 kernel/events/core.c:5957 perf_pending_event+0x12d/0x170 kernel/events/core.c:6013 irq_work_run_list+0xea/0x140 kernel/irq_work.c:165 irq_work_run+0x48/0xa0 kernel/irq_work.c:180 smp_irq_work_interrupt+0x71/0x1c0 arch/x86/kernel/irq_work.c:21 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:861 arch_local_irq_enable arch/x86/include/asm/paravirt.h:766 [inline] preempt_schedule_irq+0x4d/0x90 kernel/sched/core.c:4318 restore_regs_and_return_to_kernel+0x0/0x25 __read_once_size include/linux/compiler.h:227 [inline] arch_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline] atomic64_read include/asm-generic/atomic-instrumented.h:850 [inline] atomic_long_read include/asm-generic/atomic-long.h:28 [inline] find_watchpoint kernel/kcsan/core.c:68 [inline] check_access kernel/kcsan/core.c:388 [inline] __tsan_read1+0x66/0x1e0 kernel/kcsan/core.c:527 vsnprintf+0x582/0xb40 lib/vsprintf.c:2464 seq_vprintf+0xaa/0xf0 fs/seq_file.c:403 seq_printf+0x6c/0x90 fs/seq_file.c:418 igmp_mc_seq_show+0x26b/0x3a0 net/ipv4/igmp.c:2853 seq_read+0x792/0x960 fs/seq_file.c:268 proc_reg_read+0xe9/0x140 fs/proc/inode.c:223 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x357/0x3d0 fs/read_write.c:935 vfs_readv+0x9c/0xf0 fs/read_write.c:997 do_preadv+0x131/0x1d0 fs/read_write.c:1089 __do_sys_preadv fs/read_write.c:1139 [inline] __se_sys_preadv fs/read_write.c:1134 [inline] __x64_sys_preadv+0x61/0x80 fs/read_write.c:1134 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: 0 PID: 17041 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 ==================================================================