==================================================================
BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2627 [inline]
BUG: KASAN: use-after-free in ext4_ext_remove_space+0x276c/0x37c8 fs/ext4/extents.c:2965
Read of size 4 at addr ffff0000fded5c18 by task syz-executor/6564

CPU: 1 UID: 0 PID: 6564 Comm: syz-executor 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+0xa8/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0xb0/0x110 mm/kasan/report.c:595
 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
 ext4_ext_rm_leaf fs/ext4/extents.c:2627 [inline]
 ext4_ext_remove_space+0x276c/0x37c8 fs/ext4/extents.c:2965
 ext4_ext_truncate+0x134/0x1d0 fs/ext4/extents.c:4484
 ext4_truncate+0xa7c/0x109c fs/ext4/inode.c:4614
 ext4_evict_inode+0x9d8/0x1084 fs/ext4/inode.c:261
 evict+0x414/0x928 fs/inode.c:810
 iput_final fs/inode.c:1914 [inline]
 iput+0x95c/0xad4 fs/inode.c:1966
 do_unlinkat+0x300/0x488 fs/namei.c:4744
 __do_sys_unlinkat fs/namei.c:4778 [inline]
 __se_sys_unlinkat fs/namei.c:4771 [inline]
 __arm64_sys_unlinkat+0xdc/0xf8 fs/namei.c:4771
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 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+0x5c/0x254 arch/arm64/kernel/entry-common.c:746
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
 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:0x20f4b pfn:0x13ded5
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc3f7b588 fffffdffc3f7b508 0000000000000000
raw: 0000000000020f4b 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000fded5b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000fded5b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000fded5c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff0000fded5c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000fded5d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop4): mb_free_blocks:2017: group 0, inode 20: block 273:freeing already freed block (bit 17); block bitmap corrupt.
EXT4-fs (loop4): Remounting filesystem read-only
EXT4-fs warning (device loop4): ext4_evict_inode:274: xattr delete (err -30)
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.