syzbot
kernel BUG in ext4_ext_insert_extent
Status:
auto-obsoleted due to no activity on 2026/10/18 22:51
Reported-by: syzbot+e67f274f1d95b6782e59@syzkaller.appspotmail.com
First crash: 390d, last: 165d
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Last patch testing requests (10)
Sample crash report:
EXT4-fs (loop2): pa ffff88813458a2a0: logic 16, phys. 177, len 21
EXT4-fs error (device loop2): ext4_mb_release_inode_pa:4367: group 0, free 19, pa_free 18
------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:2135!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1891 Comm: syz.2.412 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_ext_insert_extent+0x4592/0x45d0 fs/ext4/extents.c:2135
Code: ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c 08 e9 ff ff 48 89 df e8 ff 50 d4 ff e9 fb e8 ff ff e8 75 cf 99 ff 0f 0b e8 6e cf 99 ff <0f> 0b e8 67 cf 99 ff 0f 0b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 30
RSP: 0018:ffffc90000d560e0 EFLAGS: 00010293
RAX: ffffffff81cae782 RBX: ffff888140996400 RCX: ffff888112164f00
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000010
RBP: ffffc90000d56290 R08: ffff88811cbc8f1f R09: 1ffff110239791e3
R10: dffffc0000000000 R11: ffffed10239791e4 R12: 0000000000000010
R13: 1ffff110215d7f88 R14: ffff888140996424 R15: 0000000000000010
FS: 00007f69fd7596c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e2ae614c0 CR3: 000000010f335000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ext4_ext_map_blocks+0x1709/0x5e00 fs/ext4/extents.c:4372
ext4_map_blocks+0x985/0x1bd0 fs/ext4/inode.c:674
_ext4_get_block+0x1d1/0x4e0 fs/ext4/inode.c:817
ext4_get_block_unwritten+0x2a/0x40 fs/ext4/inode.c:848
ext4_block_write_begin+0x573/0x1340 fs/ext4/inode.c:1101
ext4_write_begin+0x67e/0x1690 fs/ext4/ext4_jbd2.h:-1
ext4_da_write_begin+0x478/0xf10 fs/ext4/inode.c:3033
generic_perform_write+0x2ce/0x540 mm/filemap.c:3509
ext4_buffered_write_iter+0x4b8/0x640 fs/ext4/file.c:271
ext4_file_write_iter+0x53f/0x1980 fs/ext4/file.c:-1
__kernel_write+0x535/0x910 fs/read_write.c:550
dump_emit+0x246/0x370 fs/coredump.c:855
dump_user_range+0x6a/0x1a0 fs/coredump.c:908
elf_core_dump+0x2866/0x2cc0 fs/binfmt_elf.c:2290
do_coredump+0x1ba3/0x28e0 fs/coredump.c:817
get_signal+0xf23/0x12e0 kernel/signal.c:2779
arch_do_signal_or_restart+0xe2/0x11d0 arch/x86/kernel/signal.c:805
handle_signal_work kernel/entry/common.c:145 [inline]
exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169
exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199
irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:287
irqentry_exit+0x12/0x60 kernel/entry/common.c:375
exc_general_protection+0x1ca/0x250 arch/x86/kernel/traps.c:557
asm_exc_general_protection+0x1e/0x30 arch/x86/include/asm/idtentry.h:565
RIP: 0033:0x7f69fecfede1
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:00002000000000b0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f69fef77fa0 RCX: 00007f69fecfedd9
RDX: 00002000000000c0 RSI: 00002000000000b0 RDI: 0000000000008400
RBP: 00007f69fed94d69 R08: 0000200000000180 R09: 0000200000000180
R10: 0000200000000100 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f69fef78038 R14: 00007f69fef77fa0 R15: 00007ffd69e7e288
Modules linked in:
---[ end trace 412407d5e7c16e24 ]---
RIP: 0010:ext4_ext_insert_extent+0x4592/0x45d0 fs/ext4/extents.c:2135
Code: ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c 08 e9 ff ff 48 89 df e8 ff 50 d4 ff e9 fb e8 ff ff e8 75 cf 99 ff 0f 0b e8 6e cf 99 ff <0f> 0b e8 67 cf 99 ff 0f 0b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 30
RSP: 0018:ffffc90000d560e0 EFLAGS: 00010293
RAX: ffffffff81cae782 RBX: ffff888140996400 RCX: ffff888112164f00
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000010
RBP: ffffc90000d56290 R08: ffff88811cbc8f1f R09: 1ffff110239791e3
R10: dffffc0000000000 R11: ffffed10239791e4 R12: 0000000000000010
R13: 1ffff110215d7f88 R14: ffff888140996424 R15: 0000000000000010
FS: 00007f69fd7596c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056426aa3daf8 CR3: 000000010f335000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
* Struck through repros no longer work on HEAD.