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KCSAN: data-race in munlock_folio / need_mlock_drain (4)

Status: auto-obsoleted due to no activity on 2024/05/31 11:19
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+8b556a2f194286719db7@syzkaller.appspotmail.com
First crash: 56d, last: 56d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in munlock_folio / need_mlock_drain mm 1 417d 417d 0/27 auto-obsoleted due to no activity on 2023/06/05 22:24
upstream KCSAN: data-race in munlock_folio / need_mlock_drain (2) mm 1 262d 262d 0/27 auto-obsoleted due to no activity on 2023/11/07 10:03
upstream KCSAN: data-race in munlock_folio / need_mlock_drain (5) mm 4 7d20h 19d 0/27 moderation: reported on 2024/06/02 17:40
upstream KCSAN: data-race in munlock_folio / need_mlock_drain (3) mm 2 159d 188d 0/27 auto-obsoleted due to no activity on 2024/02/18 23:01

Sample crash report:
EXT4-fs (loop4): unmounting filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09.
==================================================================
BUG: KCSAN: data-race in munlock_folio / need_mlock_drain

read-write to 0xffff888237d2b410 of 1 bytes by task 22368 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 munlock_folio+0x42/0x130 mm/mlock.c:301
 munlock_vma_folio mm/internal.h:782 [inline]
 __folio_remove_rmap mm/rmap.c:1573 [inline]
 folio_remove_rmap_ptes+0x179/0x180 mm/rmap.c:1590
 zap_present_folio_ptes mm/memory.c:1503 [inline]
 zap_present_ptes mm/memory.c:1563 [inline]
 zap_pte_range mm/memory.c:1605 [inline]
 zap_pmd_range mm/memory.c:1722 [inline]
 zap_pud_range mm/memory.c:1751 [inline]
 zap_p4d_range mm/memory.c:1772 [inline]
 unmap_page_range+0xe36/0x22d0 mm/memory.c:1793
 unmap_single_vma+0x142/0x1d0 mm/memory.c:1839
 unmap_vmas+0x18d/0x2b0 mm/memory.c:1883
 exit_mmap+0x1a2/0x6f0 mm/mmap.c:3267
 __mmput+0x28/0x1c0 kernel/fork.c:1346
 mmput+0x4c/0x60 kernel/fork.c:1368
 exit_mm+0xe4/0x190 kernel/exit.c:569
 do_exit+0x57e/0x1740 kernel/exit.c:865
 do_group_exit+0x102/0x150 kernel/exit.c:1027
 get_signal+0xf2f/0x1080 kernel/signal.c:2911
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d2b410 of 1 bytes by task 21506 on cpu 0:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 need_mlock_drain+0x30/0x50 mm/mlock.c:235
 cpu_needs_drain mm/swap.c:816 [inline]
 __lru_add_drain_all+0x240/0x420 mm/swap.c:904
 lru_add_drain_all+0x10/0x20 mm/swap.c:920
 invalidate_bdev+0x54/0x80 block/bdev.c:95
 ext4_put_super+0x51b/0x7e0 fs/ext4/super.c:1361
 generic_shutdown_super+0xde/0x210 fs/super.c:641
 kill_block_super+0x2a/0x70 fs/super.c:1675
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7327
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:472
 deactivate_super+0x9f/0xb0 fs/super.c:505
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1267
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1274
 task_work_run+0x13a/0x1a0 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x14 -> 0x1f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21506 Comm: syz-executor.4 Tainted: G        W          6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop4): unmounting filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000d40000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000d40000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/26 11:19 upstream c942a0cd3603 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in munlock_folio / need_mlock_drain
* Struck through repros no longer work on HEAD.