EXT2-fs (loop0): nobh option not supported
EXT2-fs (loop0): warning: mounting ext3 filesystem as ext2
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BUG: KASAN: use-after-free in _find_next_zero_bit+0xac/0xe4 lib/find_bit.c:222
Read of size 8 at addr ffff0000e890a000 by task syz.0.17/6698

CPU: 1 UID: 0 PID: 6698 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0x8c/0x21c mm/kasan/report.c:378
 print_report+0x50/0x68 mm/kasan/report.c:482
 kasan_report+0xb0/0x110 mm/kasan/report.c:595
 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
 _find_next_zero_bit+0xac/0xe4 lib/find_bit.c:222
 find_next_zero_bit include/linux/find.h:192 [inline]
 find_next_zero_bit_le include/linux/find.h:512 [inline]
 bitmap_search_next_usable_block fs/ext2/balloc.c:588 [inline]
 alloc_new_reservation fs/ext2/balloc.c:961 [inline]
 ext2_try_to_allocate_with_rsv+0xb58/0x12a8 fs/ext2/balloc.c:1113
 ext2_new_blocks+0x630/0x1124 fs/ext2/balloc.c:1304
 ext2_alloc_blocks fs/ext2/inode.c:422 [inline]
 ext2_alloc_branch fs/ext2/inode.c:491 [inline]
 ext2_get_blocks+0xb04/0x1b68 fs/ext2/inode.c:734
 ext2_get_block+0xc8/0x3f4 fs/ext2/inode.c:791
 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145
 block_write_begin+0xa0/0x128 fs/buffer.c:2256
 ext2_write_begin+0x44/0x88 fs/ext2/inode.c:933
 generic_perform_write+0x244/0x7bc mm/filemap.c:4175
 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4292
 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4318
 ext2_file_write_iter+0xec/0x1194 fs/ext2/file.c:304
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x540/0xa3c fs/read_write.c:686
 ksys_write+0x120/0x210 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:746
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff9a7bb pfn:0x12890a
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc3b7ff48 fffffdffc3980ec8 0000000000000000
raw: 0000000ffff9a7bb 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e8909f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000e8909f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000e890a000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000e890a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e890a100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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