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KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio (4)

Status: moderation: reported on 2025/10/07 19:12
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+6d0cfc7b41534e0498aa@syzkaller.appspotmail.com
First crash: 1d19h, last: 1d19h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio (3) mm 6 1 524d 524d 0/29 auto-obsoleted due to no activity on 2024/06/06 20:44
upstream KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio mm 6 1 1186d 1186d 0/29 auto-closed as invalid on 2022/08/15 13:18
upstream KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio (2) mm 6 1 934d 934d 0/29 auto-obsoleted due to no activity on 2023/05/01 12:19

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio

read-write to 0xffff888237d25fe8 of 1 bytes by task 13053 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 deactivate_file_folio+0xb6/0x1b0 mm/swap.c:695
 mapping_try_invalidate+0x2a6/0x3f0 mm/truncate.c:542
 invalidate_mapping_pages+0x27/0x40 mm/truncate.c:577
 invalidate_bdev+0x58/0x70 block/bdev.c:102
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1348
 generic_shutdown_super+0xe6/0x210 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1722
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7403
 deactivate_locked_super+0x75/0x1c0 fs/super.c:473
 deactivate_super+0x97/0xa0 fs/super.c:506
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1327
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1334
 task_work_run+0x131/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xed/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d25fe8 of 1 bytes by task 3002 on cpu 0:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:782 [inline]
 __lru_add_drain_all+0x1d5/0x450 mm/swap.c:877
 lru_add_drain_all+0x10/0x20 mm/swap.c:893
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 bdev_disk_changed+0xeb/0xcb0 block/partitions/core.c:657
 blkdev_get_whole+0x1f5/0x2d0 block/bdev.c:748
 bdev_open+0x280/0x7e0 block/bdev.c:957
 bdev_file_open_by_dev+0x1e6/0x250 block/bdev.c:1059
 disk_scan_partitions+0x148/0x1b0 block/genhd.c:387
 blkdev_common_ioctl+0x10bf/0x1ad0 block/ioctl.c:625
 blkdev_ioctl+0x2ee/0x440 block/ioctl.c:699
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1816/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x01 -> 0x02

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3002 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================
 loop4: p1 p3 < >
 loop4: p1 p3 < >

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/07 19:12 upstream 971199ad2a0f 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio
* Struck through repros no longer work on HEAD.