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KCSAN: data-race in mlock_new_folio / need_mlock_drain

Status: auto-obsoleted due to no activity on 2023/11/08 14:06
Subsystems: mm
[Documentation on labels]
First crash: 278d, last: 254d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in mlock_new_folio / need_mlock_drain (3) mm 9 2d18h 65d 0/27 moderation: reported on 2024/04/11 03:51
upstream KCSAN: data-race in mlock_new_folio / need_mlock_drain (2) mm 8 104d 188d 0/27 auto-obsoleted due to no activity on 2024/04/07 03:38

Sample crash report:
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in mlock_new_folio / need_mlock_drain

read-write to 0xffff888237d29f28 of 1 bytes by task 2425 on cpu 1:
 folio_batch_add include/linux/pagevec.h:74 [inline]
 mlock_new_folio+0x109/0x1f0 mm/mlock.c:281
 folio_add_lru_vma+0x14d/0x160 mm/swap.c:535
 do_anonymous_page mm/memory.c:4152 [inline]
 do_pte_missing mm/memory.c:3667 [inline]
 handle_pte_fault mm/memory.c:4978 [inline]
 __handle_mm_fault mm/memory.c:5119 [inline]
 handle_mm_fault+0x1cb7/0x2cc0 mm/memory.c:5284
 faultin_page mm/gup.c:956 [inline]
 __get_user_pages+0x402/0xe40 mm/gup.c:1239
 populate_vma_page_range mm/gup.c:1666 [inline]
 __mm_populate+0x216/0x330 mm/gup.c:1775
 mm_populate include/linux/mm.h:3305 [inline]
 __do_sys_mlockall mm/mlock.c:729 [inline]
 __se_sys_mlockall+0x28d/0x320 mm/mlock.c:705
 __x64_sys_mlockall+0x1f/0x30 mm/mlock.c:705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888237d29f28 of 1 bytes by task 3087 on cpu 0:
 folio_batch_count include/linux/pagevec.h:53 [inline]
 need_mlock_drain+0x30/0x50 mm/mlock.c:236
 cpu_needs_drain mm/swap.c:801 [inline]
 __lru_add_drain_all+0x240/0x420 mm/swap.c:889
 lru_add_drain_all+0x10/0x20 mm/swap.c:905
 invalidate_bdev+0x54/0x70 block/bdev.c:86
 ext4_put_super+0x51b/0x7d0 fs/ext4/super.c:1353
 generic_shutdown_super+0xdb/0x210 fs/super.c:693
 kill_block_super+0x2a/0x60 fs/super.c:1646
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7305
 deactivate_locked_super+0x73/0x1c0 fs/super.c:481
 deactivate_super+0x9b/0xb0 fs/super.c:514
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1254
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1261
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd6/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00 -> 0x06

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3087 Comm: syz-executor.3 Not tainted 6.6.0-rc4-syzkaller-00029-gcbf3a2cb156a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
==================================================================
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/04 14:03 upstream cbf3a2cb156a b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mlock_new_folio / need_mlock_drain
2023/09/10 12:14 upstream 535a265d7f0d 6654cf89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mlock_new_folio / need_mlock_drain
* Struck through repros no longer work on HEAD.