loop2: detected capacity change from 0 to 512
EXT4-fs error (device loop2): ext4_ext_check_inode:520: inode #2: comm syz.2.178: pblk 0 bad header/extent: invalid magic - magic 5, entries 0, max 4(0), depth 0(0)
EXT4-fs (loop2): get root inode failed
EXT4-fs (loop2): mount failed
==================================================================
BUG: KCSAN: data-race in mlock_folio / need_mlock_drain

read-write to 0xffff888237c2b370 of 1 bytes by task 4000 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_folio+0x136/0x210 mm/mlock.c:257
 mlock_vma_folio mm/internal.h:895 [inline]
 __folio_add_file_rmap mm/rmap.c:1470 [inline]
 folio_add_file_rmap_ptes+0x1c2/0x1d0 mm/rmap.c:1487
 set_pte_range+0x206/0x430 mm/memory.c:4804
 filemap_map_order0_folio mm/filemap.c:3594 [inline]
 filemap_map_pages+0x643/0x9f0 mm/filemap.c:3644
 do_fault_around mm/memory.c:5019 [inline]
 do_read_fault mm/memory.c:5052 [inline]
 do_fault mm/memory.c:5191 [inline]
 do_pte_missing mm/memory.c:3947 [inline]
 handle_pte_fault mm/memory.c:5522 [inline]
 __handle_mm_fault mm/memory.c:5665 [inline]
 handle_mm_fault+0x10d4/0x2940 mm/memory.c:5833
 faultin_page mm/gup.c:1194 [inline]
 __get_user_pages+0x499/0x10d0 mm/gup.c:1493
 populate_vma_page_range mm/gup.c:1932 [inline]
 __mm_populate+0x25b/0x3b0 mm/gup.c:2035
 mm_populate include/linux/mm.h:3415 [inline]
 __do_sys_mlockall mm/mlock.c:766 [inline]
 __se_sys_mlockall+0x2c5/0x370 mm/mlock.c:742
 __x64_sys_mlockall+0x1f/0x30 mm/mlock.c:742
 x64_sys_call+0x2806/0x2e00 arch/x86/include/generated/asm/syscalls_64.h:152
 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 0xffff888237c2b370 of 1 bytes by task 4022 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:824 [inline]
 __lru_add_drain_all+0x235/0x410 mm/swap.c:912
 lru_add_drain_all+0x10/0x20 mm/swap.c:928
 invalidate_bdev+0x47/0x70 block/bdev.c:100
 __ext4_fill_super fs/ext4/super.c:5639 [inline]
 ext4_fill_super+0x6f3/0x39e0 fs/ext4/super.c:5664
 get_tree_bdev+0x256/0x2e0 fs/super.c:1635
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5696
 vfs_get_tree+0x56/0x1d0 fs/super.c:1800
 do_new_mount+0x227/0x690 fs/namespace.c:3472
 path_mount+0x49b/0xb30 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount+0x27c/0x2d0 fs/namespace.c:3997
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3997
 x64_sys_call+0xd11/0x2e00 arch/x86/include/generated/asm/syscalls_64.h:166
 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

value changed: 0x01 -> 0x0c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4022 Comm: syz.2.178 Not tainted 6.11.0-rc1-syzkaller-00063-g21b136cc63d2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================
loop2: detected capacity change from 0 to 1024
EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.