EXT4-fs (loop2): 1 orphan inode deleted
EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: writeback.
ext4 filesystem being mounted at /0/file0 supports timestamps until 2038-01-19 (0x7fffffff)
EXT4-fs error (device loop2): ext4_xattr_block_get:546: inode #15: comm syz.2.16: corrupted xattr block 19
==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:827 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946
Read of size 4 at addr ffff88812ec2c84c by task syz.2.16/368

CPU: 1 PID: 368 Comm: syz.2.16 Not tainted 5.15.185-syzkaller-00207-g32c443bd6d40 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0xf1/0x140 mm/kasan/report.c:444
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_ext_binsearch fs/ext4/extents.c:827 [inline]
 ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946
 ext4_ext_remove_space+0x2bc/0x4180 fs/ext4/extents.c:2831
 ext4_punch_hole+0x77c/0xbd0 fs/ext4/inode.c:4131
 ext4_fallocate+0x2b6/0x1de0 fs/ext4/extents.c:4763
 vfs_fallocate+0x4b4/0x590 fs/open.c:309
 ksys_fallocate fs/open.c:332 [inline]
 __do_sys_fallocate fs/open.c:340 [inline]
 __se_sys_fallocate fs/open.c:338 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:338
 x64_sys_call+0x7ec/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:286
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7efcfd37c929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffc57fd8c28 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007efcfd5a3fa0 RCX: 00007efcfd37c929
RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007efcfd3feb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efcfd5a3fa0 R14: 00007efcfd5a3fa0 R15: 0000000000000004
 </TASK>

The buggy address belongs to the page:
page:ffffea0004bb0b00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12ec2c
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004bb0b08 ffffea0004bb0b08 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:
 ffff88812ec2c700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812ec2c780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812ec2c800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88812ec2c880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812ec2c900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:3185!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 368 Comm: syz.2.16 Tainted: G    B             5.15.185-syzkaller-00207-g32c443bd6d40 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:ext4_split_extent_at+0xe77/0xe90 fs/ext4/extents.c:3185
Code: 6f fb ff ff 48 89 df 49 89 d7 e8 34 84 d3 ff 4c 89 fa e9 5c fb ff ff e8 d7 0d 95 ff 0f 0b e8 d0 0d 95 ff 0f 0b e8 c9 0d 95 ff <0f> 0b e8 c2 0d 95 ff 0f 0b e8 bb 0d 95 ff 0f 0b e8 b4 0d 95 ff 0f
RSP: 0018:ffffc90000b97940 EFLAGS: 00010293
RAX: ffffffff81d39a67 RBX: 1ffff11025d8a212 RCX: ffff88810f908000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000010
RBP: ffffc90000b97ab0 R08: 0000000000000000 R09: 0000000050000028
R10: fffffbfff0e17a4c R11: 1ffffffff0e17a4c R12: dffffc0000000000
R13: 0000000000000010 R14: 0000000000000000 R15: 0000000000000000
FS:  0000555591998500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000020000 CR3: 000000012d2b1000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_force_split_extent_at fs/ext4/extents.c:319 [inline]
 ext4_ext_remove_space+0x64b/0x4180 fs/ext4/extents.c:2878
 ext4_punch_hole+0x77c/0xbd0 fs/ext4/inode.c:4131
 ext4_fallocate+0x2b6/0x1de0 fs/ext4/extents.c:4763
 vfs_fallocate+0x4b4/0x590 fs/open.c:309
 ksys_fallocate fs/open.c:332 [inline]
 __do_sys_fallocate fs/open.c:340 [inline]
 __se_sys_fallocate fs/open.c:338 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:338
 x64_sys_call+0x7ec/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:286
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7efcfd37c929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffc57fd8c28 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007efcfd5a3fa0 RCX: 00007efcfd37c929
RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007efcfd3feb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efcfd5a3fa0 R14: 00007efcfd5a3fa0 R15: 0000000000000004
 </TASK>
Modules linked in:
---[ end trace cdac5d806dbdf8e3 ]---
RIP: 0010:ext4_split_extent_at+0xe77/0xe90 fs/ext4/extents.c:3185
Code: 6f fb ff ff 48 89 df 49 89 d7 e8 34 84 d3 ff 4c 89 fa e9 5c fb ff ff e8 d7 0d 95 ff 0f 0b e8 d0 0d 95 ff 0f 0b e8 c9 0d 95 ff <0f> 0b e8 c2 0d 95 ff 0f 0b e8 bb 0d 95 ff 0f 0b e8 b4 0d 95 ff 0f
RSP: 0018:ffffc90000b97940 EFLAGS: 00010293
RAX: ffffffff81d39a67 RBX: 1ffff11025d8a212 RCX: ffff88810f908000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000010
RBP: ffffc90000b97ab0 R08: 0000000000000000 R09: 0000000050000028
R10: fffffbfff0e17a4c R11: 1ffffffff0e17a4c R12: dffffc0000000000
R13: 0000000000000010 R14: 0000000000000000 R15: 0000000000000000
FS:  0000555591998500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000020000 CR3: 000000012d2b1000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400