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EXT4-fs (loop3): Remounting filesystem read-only
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kernel BUG at fs/ext4/mballoc.c:4877!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 403 Comm: syz.3.22 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_mb_release_inode_pa+0xa8e/0xa90 fs/ext4/mballoc.c:4877
Code: 80 c2 03 38 c2 0f 8c 2f fe ff ff 48 89 df 41 89 ce e8 c6 88 cb ff 44 89 f1 e9 1c fe ff ff e8 d9 0a 8c ff 0f 0b e8 d2 0a 8c ff <0f> 0b 55 48 89 e5 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc
RSP: 0018:ffffc90000be68e0 EFLAGS: 00010293
RAX: ffffffff81ddd68e RBX: 0000000000000503 RCX: ffff888113c82780
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90000be6a30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200017cd38 R12: 1ffff9200017cd34
R13: dffffc0000000000 R14: 0000000000000060 R15: ffff888120aafb28
FS:  00007f39cfcc76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555d01908 CR3: 00000001329d9000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_mb_discard_group_preallocations+0xbaa/0xdf0 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+0x30d7/0x4220 fs/ext4/mballoc.c:5816
 ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
 ext4_ind_map_blocks+0xda7/0x2010 fs/ext4/indirect.c:635
 ext4_map_blocks+0x926/0x1b30 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+0x563/0x1160 fs/ext4/inode.c:1104
 ext4_write_begin+0x65a/0x12e0 fs/ext4/ext4_jbd2.h:-1
 generic_perform_write+0x2b7/0x690 mm/filemap.c:3870
 ext4_buffered_write_iter+0x4ed/0x670 fs/ext4/file.c:270
 ext4_file_write_iter+0x440/0x1540 fs/ext4/file.c:-1
 do_iter_readv_writev+0x478/0x5f0 fs/read_write.c:-1
 do_iter_write+0x1fa/0x7b0 fs/read_write.c:855
 vfs_writev+0x2df/0x570 fs/read_write.c:928
 do_writev+0x14e/0x2c0 fs/read_write.c:971
 __do_sys_writev fs/read_write.c:1044 [inline]
 __se_sys_writev fs/read_write.c:1041 [inline]
 __x64_sys_writev+0x7d/0x90 fs/read_write.c:1041
 x64_sys_call+0x974/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:21
 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: 0033:0x7f39cfe64e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f39cfcc7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f39d00ddfa0 RCX: 00007f39cfe64e59
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f39cfefad6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f39d00de038 R14: 00007f39d00ddfa0 R15: 00007ffc6250f5d8
 </TASK>
Modules linked in:
---[ end trace 6b136c051d3acbf1 ]---
RIP: 0010:ext4_mb_release_inode_pa+0xa8e/0xa90 fs/ext4/mballoc.c:4877
Code: 80 c2 03 38 c2 0f 8c 2f fe ff ff 48 89 df 41 89 ce e8 c6 88 cb ff 44 89 f1 e9 1c fe ff ff e8 d9 0a 8c ff 0f 0b e8 d2 0a 8c ff <0f> 0b 55 48 89 e5 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc
RSP: 0018:ffffc90000be68e0 EFLAGS: 00010293
RAX: ffffffff81ddd68e RBX: 0000000000000503 RCX: ffff888113c82780
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90000be6a30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200017cd38 R12: 1ffff9200017cd34
R13: dffffc0000000000 R14: 0000000000000060 R15: ffff888120aafb28
FS:  00007f39cfcc76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555d01908 CR3: 00000001329d9000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400