loop0: detected capacity change from 0 to 2048
EXT4-fs (loop0): bad block size 8192
==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c25ee8 of 1 bytes by task 3318 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 folio_add_lru+0xa5/0x1f0 mm/swap.c:511
 folio_add_lru_vma+0x49/0x70 mm/swap.c:530
 do_anonymous_page mm/memory.c:5101 [inline]
 do_pte_missing mm/memory.c:4232 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x281f/0x2c20 mm/memory.c:6364
 do_user_addr_fault+0x3fe/0x1090 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
 rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:68
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
 copy_to_user_iter lib/iov_iter.c:25 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 _copy_to_iter+0x141/0xe70 lib/iov_iter.c:185
 copy_page_to_iter+0x18f/0x2d0 lib/iov_iter.c:362
 copy_folio_to_iter include/linux/uio.h:204 [inline]
 filemap_read+0x407/0xa00 mm/filemap.c:2763
 blkdev_read_iter+0x22d/0x2e0 block/fops.c:852
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x64c/0x770 fs/read_write.c:572
 ksys_read+0xda/0x1a0 fs/read_write.c:715
 __do_sys_read fs/read_write.c:724 [inline]
 __se_sys_read fs/read_write.c:722 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:722
 x64_sys_call+0x27bc/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:1
 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

read to 0xffff888237c25ee8 of 1 bytes by task 6658 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:780 [inline]
 __lru_add_drain_all+0x12b/0x3f0 mm/swap.c:874
 lru_add_drain_all+0x10/0x20 mm/swap.c:890
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 __ext4_fill_super fs/ext4/super.c:5709 [inline]
 ext4_fill_super+0x2b5d/0x35d0 fs/ext4/super.c:5734
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1692
 get_tree_bdev+0x1f/0x30 fs/super.c:1715
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5766
 vfs_get_tree+0x57/0x1d0 fs/super.c:1752
 do_new_mount+0x207/0x600 fs/namespace.c:3750
 path_mount+0x4a4/0xb30 fs/namespace.c:4065
 do_mount fs/namespace.c:4078 [inline]
 __do_sys_mount fs/namespace.c:4278 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4255
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4255
 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166
 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: 0x07 -> 0x08

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6658 Comm: syz.0.1503 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================