EXT4-fs error (device loop5): mb_free_blocks:2037: group 0, inode 15: block 305:freeing already freed block (bit 19); block bitmap corrupt.
------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:2153!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 7039 Comm: syz.5.50 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ext4_ext_insert_extent+0x4ab7/0x4af0 fs/ext4/extents.c:2153
Code: 89 d9 80 e1 07 fe c1 38 c1 0f 8c a6 e7 ff ff 48 89 df e8 2c b4 b3 ff e9 99 e7 ff ff e8 b2 5d 4d ff 90 0f 0b e8 aa 5d 4d ff 90 <0f> 0b e8 a2 5d 4d ff 90 0f 0b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c
RSP: 0018:ffffc90004c3ec20 EFLAGS: 00010293
RAX: ffffffff82745356 RBX: 0000000000000021 RCX: ffff88802b525b80
RDX: 0000000000000000 RSI: 0000000000000021 RDI: 0000000000000021
RBP: ffffc90004c3edd0 R08: ffff88805bcbe007 R09: 1ffff1100b797c00
R10: dffffc0000000000 R11: ffffed100b797c01 R12: 0000000000000021
R13: dffffc0000000000 R14: ffff88807107a454 R15: ffff88805cb14200
FS:  00007f2cfaf326c0(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003000 CR3: 00000000569bd000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ext4_ext_map_blocks+0x19ef/0x69c0 fs/ext4/extents.c:4404
 ext4_map_create_blocks fs/ext4/inode.c:613 [inline]
 ext4_map_blocks+0x82c/0x16f0 fs/ext4/inode.c:816
 _ext4_get_block+0x1fa/0x4c0 fs/ext4/inode.c:916
 ext4_get_block_unwritten+0x2e/0x100 fs/ext4/inode.c:949
 ext4_block_write_begin+0xb03/0x1940 fs/ext4/inode.c:1203
 ext4_write_begin+0xb3a/0x1860 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x352/0xd30 fs/ext4/inode.c:3130
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4314
 ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
 ext4_file_write_iter+0x292/0x1bc0 fs/ext4/file.c:-1
 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1
 vfs_writev+0x31a/0x960 fs/read_write.c:1057
 do_pwritev fs/read_write.c:1153 [inline]
 __do_sys_pwritev2 fs/read_write.c:1211 [inline]
 __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2cfa18e929
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:00007f2cfaf32038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f2cfa3b5fa0 RCX: 00007f2cfa18e929
RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007f2cfa210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000005412 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2cfa3b5fa0 R15: 00007fff3aa19198
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_ext_insert_extent+0x4ab7/0x4af0 fs/ext4/extents.c:2153
Code: 89 d9 80 e1 07 fe c1 38 c1 0f 8c a6 e7 ff ff 48 89 df e8 2c b4 b3 ff e9 99 e7 ff ff e8 b2 5d 4d ff 90 0f 0b e8 aa 5d 4d ff 90 <0f> 0b e8 a2 5d 4d ff 90 0f 0b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c
RSP: 0018:ffffc90004c3ec20 EFLAGS: 00010293
RAX: ffffffff82745356 RBX: 0000000000000021 RCX: ffff88802b525b80
RDX: 0000000000000000 RSI: 0000000000000021 RDI: 0000000000000021
RBP: ffffc90004c3edd0 R08: ffff88805bcbe007 R09: 1ffff1100b797c00
R10: dffffc0000000000 R11: ffffed100b797c01 R12: 0000000000000021
R13: dffffc0000000000 R14: ffff88807107a454 R15: ffff88805cb14200
FS:  00007f2cfaf326c0(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e4f388a10 CR3: 00000000569bd000 CR4: 0000000000350ef0