syzbot
general protection fault in jbd2_journal_file_inode
Status:
upstream: reported C repro on 2026/11/13 09:28
Reported-by: syzbot+e4eab3cad4e76394daeb@syzkaller.appspotmail.com
First crash: 4h53m, last: 4h37m
Sample crash report:
EXT4-fs (loop0): Using encoding defined by superblock: utf8-12.1.0 with flags 0x0
EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: dioread_nolock,auto_da_alloc=0x00000000000000b7,nojournal_checksum,i_version,,errors=continue
general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 PID: 297 Comm: syz-executor400 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
RIP: 0010:jbd2_journal_file_inode+0x143/0x580 fs/jbd2/transaction.c:2697
Code: 03 48 89 45 c0 48 8d b8 08 04 00 00 48 89 7d b8 e8 02 17 a0 02 49 8d 7e 28 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 05 e8 32 4d bc ff 4d 09 66 28 4d 8d 66 38 4d 89 e7
RSP: 0018:ffffc90000af7778 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff88810936ac80 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000028
RBP: ffffc90000af77c0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200015eee0 R12: 0000000000000006
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff1102126d590
FS: 000055557a52c3c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5850a45000 CR3: 000000011f6de000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
jbd2_journal_inode_ranged_write+0x34/0x40 fs/jbd2/transaction.c:2741
ext4_jbd2_inode_add_write fs/ext4/ext4_jbd2.h:426 [inline]
ext4_map_blocks+0x11a6/0x1b10 fs/ext4/inode.c:764
ext4_convert_inline_data_nolock+0x435/0xcc0 fs/ext4/inline.c:1273
ext4_convert_inline_data+0x470/0x5b0 fs/ext4/inline.c:2083
ext4_setattr+0xdf4/0x1980 fs/ext4/inode.c:5624
notify_change+0xab5/0xe40 fs/attr.c:410
do_truncate+0x1a3/0x240 fs/open.c:65
vfs_truncate+0x235/0x2d0 fs/open.c:111
do_sys_truncate+0xf2/0x1c0 fs/open.c:134
__do_sys_truncate fs/open.c:146 [inline]
__se_sys_truncate fs/open.c:144 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:144
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fedeae975a9
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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe8d4db588 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007ffe8d4db6c8 RCX: 00007fedeae975a9
RDX: 00007ffe8d4db410 RSI: 0000000000003c4c RDI: 0000200000000800
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8d4db6b8
R13: 0000000000000002 R14: 00007fedeaf22c80 R15: 0000000000000002
Modules linked in:
---[ end trace aae39205f9529b2b ]---
RIP: 0010:jbd2_journal_file_inode+0x143/0x580 fs/jbd2/transaction.c:2697
Code: 03 48 89 45 c0 48 8d b8 08 04 00 00 48 89 7d b8 e8 02 17 a0 02 49 8d 7e 28 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 05 e8 32 4d bc ff 4d 09 66 28 4d 8d 66 38 4d 89 e7
RSP: 0018:ffffc90000af7778 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff88810936ac80 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000028
RBP: ffffc90000af77c0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200015eee0 R12: 0000000000000006
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff1102126d590
FS: 000055557a52c3c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5850a45000 CR3: 000000011f6de000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 03 48 89 add -0x77(%rax),%ecx
3: 45 c0 48 8d b8 rex.RB rorb $0xb8,-0x73(%r8)
8: 08 04 00 or %al,(%rax,%rax,1)
b: 00 48 89 add %cl,-0x77(%rax)
e: 7d b8 jge 0xffffffc8
10: e8 02 17 a0 02 call 0x2a01717
15: 49 8d 7e 28 lea 0x28(%r14),%rdi
19: 48 89 f8 mov %rdi,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 05 je 0x35
30: e8 32 4d bc ff call 0xffbc4d67
35: 4d 09 66 28 or %r12,0x28(%r14)
39: 4d 8d 66 38 lea 0x38(%r14),%r12
3d: 4d 89 e7 mov %r12,%r15
* Struck through repros no longer work on HEAD.