==================================================================
BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2602 [inline]
BUG: KASAN: use-after-free in ext4_ext_remove_space+0x2f43/0x3fb0 fs/ext4/extents.c:2940
Read of size 4 at addr ffff88812ddf5db8 by task syz-executor/462

CPU: 0 PID: 462 Comm: syz-executor Not tainted 6.1.145-syzkaller-1169984-g3b4ff5af8d36 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x71/0x210 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:427
 kasan_report+0x122/0x150 mm/kasan/report.c:531
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350
 ext4_ext_rm_leaf fs/ext4/extents.c:2602 [inline]
 ext4_ext_remove_space+0x2f43/0x3fb0 fs/ext4/extents.c:2940
 ext4_ext_truncate+0x200/0x320 fs/ext4/extents.c:4470
 ext4_truncate+0x9a6/0xf90 fs/ext4/inode.c:4291
 ext4_evict_inode+0xcc3/0x1460 fs/ext4/inode.c:286
 evict+0x493/0x890 fs/inode.c:705
 iput_final fs/inode.c:1834 [inline]
 iput+0x620/0x670 fs/inode.c:1860
 do_unlinkat+0x375/0x6b0 fs/namei.c:4396
 __do_sys_unlink fs/namei.c:4437 [inline]
 __se_sys_unlink fs/namei.c:4435 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4435
 x64_sys_call+0x958/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa423b8df57
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd767b7f38 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa423b8df57
RDX: 00007ffd767b7f60 RSI: 00007ffd767b7ff0 RDI: 00007ffd767b7ff0
RBP: 00007ffd767b7ff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffd767b90e0
R13: 00007fa423c10b55 R14: 000000000000cc19 R15: 00007ffd767ba1b0
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0004b77d40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12ddf5
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004b77d48 ffffea0004b77d48 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffff88812ddf5c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812ddf5d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812ddf5d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                        ^
 ffff88812ddf5e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812ddf5e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs (loop2): unmounting filesystem.
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 130220965612224, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 130220965586783, count = 25454
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 130220965586768, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 56311859664480, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 56311859650608, count = 13878
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 56311859650608, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 112589990710368, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 112589990684262, count = 26122
EXT4-fs error: 34866 callbacks suppressed
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 104927652638560, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 104592895498096, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 104592895472479, count = 25632
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 104592895472464, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 112589198695824, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 112589198669624, count = 26214
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 112589198669616, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 126877799852432, count = 16
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 126877799822382, count = 30060
EXT4-fs error (device loop2): ext4_free_blocks:6210: comm syz-executor: Freeing blocks not in datazone - block = 126877799822368, count = 16