==================================================================
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 ffff0000e2279c18 by task syz.2.168/7509

CPU: 0 UID: 0 PID: 7509 Comm: syz.2.168 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+0x9c8/0xfe4 fs/ext4/inode.c:4643
 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
 ext4_write_end+0x5e0/0x8e8 fs/ext4/inode.c:1486
 ext4_da_write_end+0x90/0xb24 fs/ext4/inode.c:3277
 generic_perform_write+0x518/0x7bc mm/filemap.c:4196
 ext4_buffered_write_iter+0x2b8/0x528 fs/ext4/file.c:299
 ext4_file_write_iter+0x1d8/0x1864 fs/ext4/file.c:-1
 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+0x98/0x254 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:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 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:0xb68 pfn:0x122279
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc3889e88 fffffdffc3889e08 0000000000000000
raw: 0000000000000b68 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e2279b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e2279b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000e2279c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff0000e2279c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e2279d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
mkiss: ax0: crc mode is auto.