EXT4-fs (loop2): Remounting filesystem read-only
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:4877!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 319 Comm: syz-executor279 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:ext4_mb_release_inode_pa+0xa78/0xa80 fs/ext4/mballoc.c:4877
Code: e2 07 80 c2 03 38 c2 0f 8c 2c fe ff ff 4c 89 f7 89 cb e8 3b 7e cb ff 89 d9 e9 1b fe ff ff e8 df 0e 8c ff 0f 0b e8 d8 0e 8c ff <0f> 0b 66 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 89 fb 49 bf
RSP: 0018:ffffc90000b06b20 EFLAGS: 00010293
RAX: ffffffff81dda8d8 RBX: 00000000000013ee RCX: ffff888123c12780
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90000b06c70 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000160d80 R12: 1ffff92000160d7c
R13: dffffc0000000000 R14: 0000000000000060 R15: 0000000000000000
FS:  00007fbc91ba56c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000180 CR3: 0000000122f08000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_mb_discard_group_preallocations+0xbdb/0xe20 fs/ext4/mballoc.c:5023
 ext4_mb_discard_preallocations fs/ext4/mballoc.c:5592 [inline]
 ext4_mb_discard_preallocations_should_retry+0x156/0x600 fs/ext4/mballoc.c:5613
 ext4_mb_new_blocks+0x3019/0x4140 fs/ext4/mballoc.c:5816
 ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
 ext4_ind_map_blocks+0xdd4/0x2050 fs/ext4/indirect.c:635
 ext4_map_blocks+0x923/0x1a50 fs/ext4/inode.c:678
 _ext4_get_block+0x1ea/0x540 fs/ext4/inode.c:819
 ext4_get_block+0x39/0x50 fs/ext4/inode.c:836
 ext4_block_write_begin+0x525/0x10a0 fs/ext4/inode.c:1104
 ext4_write_begin+0x683/0x1360 fs/ext4/ext4_jbd2.h:-1
 generic_perform_write+0x2b7/0x690 mm/filemap.c:3887
 ext4_buffered_write_iter+0x4ab/0x630 fs/ext4/file.c:270
 ext4_file_write_iter+0x427/0x1530 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2212 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x831/0xfd0 fs/read_write.c:594
 ksys_write+0x14a/0x260 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:656
 x64_sys_call+0x8ef/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 0033:0x7fbc91bd2239
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 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 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbc91ba5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbc91c78e28 RCX: 00007fbc91bd2239
RDX: 000000000208e24b RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007fbc91c78e20 R08: 00007fbc91ba5cdc R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbc91c78e2c
R13: 0000000000000006 R14: 00007ffe5a6aa400 R15: 00007ffe5a6aa4e8
 </TASK>
Modules linked in:
---[ end trace 412b8768bfd49f1a ]---
RIP: 0010:ext4_mb_release_inode_pa+0xa78/0xa80 fs/ext4/mballoc.c:4877
Code: e2 07 80 c2 03 38 c2 0f 8c 2c fe ff ff 4c 89 f7 89 cb e8 3b 7e cb ff 89 d9 e9 1b fe ff ff e8 df 0e 8c ff 0f 0b e8 d8 0e 8c ff <0f> 0b 66 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 89 fb 49 bf
RSP: 0018:ffffc90000b06b20 EFLAGS: 00010293
RAX: ffffffff81dda8d8 RBX: 00000000000013ee RCX: ffff888123c12780
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90000b06c70 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000160d80 R12: 1ffff92000160d7c
R13: dffffc0000000000 R14: 0000000000000060 R15: 0000000000000000
FS:  00007fbc91ba56c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000180 CR3: 0000000122f08000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400