syzbot

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BUG: KCSAN: data-race in mlock_new_folio / need_mlock_drain

read-write to 0xffff888237c2b4a0 of 1 bytes by task 17754 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_new_folio+0x114/0x200 mm/mlock.c:280
 folio_add_lru_vma+0x5d/0x60 mm/swap.c:499
 do_anonymous_page mm/memory.c:4856 [inline]
 do_pte_missing mm/memory.c:3977 [inline]
 handle_pte_fault mm/memory.c:5801 [inline]
 __handle_mm_fault mm/memory.c:5944 [inline]
 handle_mm_fault+0x24d8/0x2ac0 mm/memory.c:6112
 faultin_page mm/gup.c:1187 [inline]
 __get_user_pages+0xf2c/0x2670 mm/gup.c:1485
 populate_vma_page_range mm/gup.c:1923 [inline]
 __mm_populate+0x25b/0x3b0 mm/gup.c:2026
 mm_populate include/linux/mm.h:3385 [inline]
 __do_sys_mremap mm/mremap.c:1213 [inline]
 __se_sys_mremap+0xbf6/0xf10 mm/mremap.c:1015
 __x64_sys_mremap+0x67/0x80 mm/mremap.c:1015
 x64_sys_call+0x27e8/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:26
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c2b4a0 of 1 bytes by task 15743 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 need_mlock_drain+0x30/0x50 mm/mlock.c:235
 cpu_needs_drain mm/swap.c:747 [inline]
 __lru_add_drain_all+0x22a/0x3f0 mm/swap.c:835
 lru_add_drain_all+0x10/0x20 mm/swap.c:851
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x571/0x840 fs/ext4/super.c:1356
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7379
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x268/0x2e0 fs/namespace.c:1373
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1380
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 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:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x1c -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 15743 Comm: syz-executor Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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