================================================================== BUG: KCSAN: data-race in __perf_event_overflow / fasync_remove_entry read to 0xffff8880acc7df00 of 8 bytes by interrupt on cpu 1: __perf_event_overflow+0x11d/0x200 kernel/events/core.c:8429 perf_swevent_hrtimer+0x261/0x280 kernel/events/core.c:9813 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1641 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:829 compound_head include/linux/page-flags.h:174 [inline] TestClearPageDirty include/linux/page-flags.h:318 [inline] clear_page_dirty_for_io+0x26b/0x580 mm/page-writeback.c:2701 mpage_submit_page+0x6d/0x1a0 fs/ext4/inode.c:2055 mpage_process_page_bufs+0x3e5/0x400 fs/ext4/inode.c:2189 mpage_prepare_extent_to_map+0x48b/0x760 fs/ext4/inode.c:2596 ext4_writepages+0x974/0x2500 fs/ext4/inode.c:2724 do_writepages+0x6b/0x170 mm/page-writeback.c:2344 __filemap_fdatawrite_range+0x1c5/0x230 mm/filemap.c:421 file_write_and_wait_range+0xfd/0x160 mm/filemap.c:782 ext4_sync_file+0x266/0xaf0 fs/ext4/fsync.c:153 vfs_fsync_range+0x82/0x150 fs/sync.c:197 generic_write_sync include/linux/fs.h:2856 [inline] ext4_buffered_write_iter+0x222/0x290 fs/ext4/file.c:259 ext4_file_write_iter+0xf4/0xd40 fs/ext4/file.c:547 call_write_iter include/linux/fs.h:1902 [inline] do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x13b/0x3c0 fs/read_write.c:951 vfs_iter_write+0x5c/0x80 fs/read_write.c:983 iter_file_splice_write+0x530/0x840 fs/splice.c:760 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0xa0/0xc0 fs/splice.c:1037 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992 do_splice_direct+0x161/0x1e0 fs/splice.c:1080 do_sendfile+0x384/0x7f0 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1525 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1511 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff8880acc7df00 of 8 bytes by task 3922 on cpu 0: 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:6002 __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:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 3922 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================