================================================================== BUG: KCSAN: data-race in __perf_event_overflow / fasync_remove_entry read to 0xffff8880a7a32b00 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 arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x51/0x80 kernel/locking/spinlock.c:191 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] test_clear_page_writeback+0x1f3/0x790 mm/page-writeback.c:2745 end_page_writeback+0x9e/0x190 mm/filemap.c:1339 ext4_finish_bio+0x40d/0x520 fs/ext4/page-io.c:148 ext4_end_bio+0xd2/0x2f0 fs/ext4/page-io.c:370 bio_endio+0x2fa/0x400 block/bio.c:1821 req_bio_endio block/blk-core.c:245 [inline] blk_update_request+0x427/0x7b0 block/blk-core.c:1464 scsi_end_request+0x6b/0x360 drivers/scsi/scsi_lib.c:576 scsi_io_completion+0x11d/0xc80 drivers/scsi/scsi_lib.c:960 scsi_finish_command+0x283/0x380 drivers/scsi/scsi.c:228 scsi_softirq_done+0x259/0x280 drivers/scsi/scsi_lib.c:1476 blk_done_softirq+0x1eb/0x250 block/blk-softirq.c:37 __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] do_IRQ+0x81/0x130 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x21 arch_local_irq_enable arch/x86/include/asm/paravirt.h:762 [inline] preempt_schedule_irq+0x4d/0x90 kernel/sched/core.c:4337 restore_regs_and_return_to_kernel+0x0/0x25 should_watch kernel/kcsan/core.c:206 [inline] check_access kernel/kcsan/core.c:458 [inline] __tsan_read4+0xb4/0x100 kernel/kcsan/core.c:588 bio_has_data include/linux/bio.h:64 [inline] submit_bio+0x77/0x3c0 block/blk-core.c:1156 submit_bh_wbc+0x40f/0x460 fs/buffer.c:3135 submit_bh fs/buffer.c:3141 [inline] __sync_dirty_buffer+0xd3/0x210 fs/buffer.c:3227 sync_dirty_buffer+0x24/0x40 fs/buffer.c:3240 ext4_write_inode+0x312/0x330 fs/ext4/inode.c:5091 write_inode fs/fs-writeback.c:1312 [inline] __writeback_single_inode+0x6f7/0x8e0 fs/fs-writeback.c:1511 writeback_single_inode+0x232/0x310 fs/fs-writeback.c:1565 sync_inode fs/fs-writeback.c:2602 [inline] sync_inode_metadata+0x74/0xa0 fs/fs-writeback.c:2622 ext4_fsync_nojournal fs/ext4/fsync.c:94 [inline] ext4_sync_file+0x4b5/0xaf0 fs/ext4/fsync.c:172 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:1519 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0xbe/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 0xffff8880a7a32b00 of 8 bytes by task 20090 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: 20090 Comm: syz-executor.2 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================