syzbot

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BUG: KCSAN: data-race in mlock_folio / need_mlock_drain

read-write to 0xffff888237d29e68 of 1 bytes by task 774 on cpu 1:
 folio_batch_add include/linux/pagevec.h:74 [inline]
 mlock_folio+0x135/0x220 mm/mlock.c:258
 mlock_vma_folio mm/internal.h:598 [inline]
 page_add_file_rmap+0x193/0x240 mm/rmap.c:1359
 do_set_pte+0x23c/0x4f0 mm/memory.c:4342
 filemap_map_pages+0x460/0x890 mm/filemap.c:3550
 do_fault_around mm/memory.c:4510 [inline]
 do_read_fault mm/memory.c:4542 [inline]
 do_fault mm/memory.c:4670 [inline]
 do_pte_missing mm/memory.c:3664 [inline]
 handle_pte_fault mm/memory.c:4939 [inline]
 __handle_mm_fault mm/memory.c:5079 [inline]
 handle_mm_fault+0x104d/0x2c10 mm/memory.c:5233
 faultin_page mm/gup.c:959 [inline]
 __get_user_pages+0x42e/0xd20 mm/gup.c:1258
 populate_vma_page_range mm/gup.c:1649 [inline]
 __mm_populate+0x23b/0x360 mm/gup.c:1758
 mm_populate include/linux/mm.h:3196 [inline]
 vm_mmap_pgoff+0x1a3/0x240 mm/util.c:548
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1408
 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 0xffff888237d29e68 of 1 bytes by task 31986 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+0x5a/0x80 block/bdev.c:86
 ext4_put_super+0x502/0x7f0 fs/ext4/super.c:1340
 generic_shutdown_super+0xd9/0x260 fs/super.c:499
 kill_block_super+0x3b/0x60 fs/super.c:1417
 deactivate_locked_super+0x6b/0xd0 fs/super.c:330
 deactivate_super+0x9b/0xb0 fs/super.c:361
 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:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd1/0xe0 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:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x02 -> 0x0f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31986 Comm: syz-executor.5 Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
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EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.