================================================================== BUG: KCSAN: data-race in hrtimer_interrupt / print_cpu write to 0xffff888237c397e0 of 8 bytes by interrupt on cpu 0: hrtimer_interrupt+0x1fb/0xaf0 kernel/time/hrtimer.c:1655 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x6f/0x1c0 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x64/0x80 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 arch_atomic_add_negative arch/x86/include/asm/atomic.h:152 [inline] atomic_add_negative include/asm-generic/atomic-instrumented.h:557 [inline] page_remove_file_rmap mm/rmap.c:1277 [inline] page_remove_rmap+0x8e/0x230 mm/rmap.c:1348 zap_pte_range+0x6ad/0xe00 mm/memory.c:1362 zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0x2dc/0x3d0 mm/memory.c:1552 unmap_single_vma+0x157/0x210 mm/memory.c:1597 unmap_vmas+0xc0/0x170 mm/memory.c:1629 exit_mmap+0x22d/0x460 mm/mmap.c:3201 __mmput+0x27/0x1c0 kernel/fork.c:1101 mmput+0x3d/0x50 kernel/fork.c:1122 exit_mm+0x2f7/0x3f0 kernel/exit.c:501 do_exit+0x402/0x1530 kernel/exit.c:812 do_group_exit+0xce/0x1a0 kernel/exit.c:922 get_signal+0xfa3/0x15e0 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302 do_syscall_64+0x49/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888237c397e0 of 8 bytes by task 29340 on cpu 1: print_cpu+0x32e/0x690 kernel/time/timer_list.c:133 timer_list_show+0x114/0x180 kernel/time/timer_list.c:291 seq_read_iter+0x60b/0x930 fs/seq_file.c:272 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:300 call_read_iter include/linux/fs.h:2108 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:311 do_splice_to fs/splice.c:796 [inline] splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x000000eaff5cda22 -> 0x000000eaff66b67b Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 29340 Comm: syz-executor.2 Not tainted 5.14.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 29340 Comm: syz-executor.2 Not tainted 5.14.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xb7/0x103 lib/dump_stack.c:105 dump_stack+0x11/0x1a lib/dump_stack.c:112 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x23c/0x250 lib/fault-inject.c:146 __should_failslab+0x81/0x90 mm/failslab.c:33 should_failslab+0x5/0x20 mm/slab_common.c:1326 slab_pre_alloc_hook mm/slab.h:494 [inline] slab_alloc mm/slab.c:3306 [inline] kmem_cache_alloc+0x46/0x2e0 mm/slab.c:3507 kmem_cache_zalloc include/linux/slab.h:711 [inline] ext4_init_io_end+0x2d/0xa0 fs/ext4/page-io.c:276 ext4_writepages+0x76d/0x1d10 fs/ext4/inode.c:2766 do_writepages+0x7b/0x150 mm/page-writeback.c:2355 __filemap_fdatawrite_range mm/filemap.c:413 [inline] file_write_and_wait_range+0x180/0x210 mm/filemap.c:792 ext4_sync_file+0x105/0x670 fs/ext4/fsync.c:151 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2987 [inline] ext4_buffered_write_iter+0x39c/0x3f0 fs/ext4/file.c:277 ext4_file_write_iter+0x2e7/0x11d0 fs/ext4/file.c:519 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe61b367188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 00007fe61b3671d0 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000010046 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffeff33dcff R14: 00007fe61b367300 R15: 0000000000022000