* [syzbot] [ext4?] general protection fault in xa_destroy
@ 2025-08-24 23:26 syzbot
2025-08-25 1:28 ` Baokun Li
0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2025-08-24 23:26 UTC (permalink / raw)
To: adilger.kernel, linux-ext4, linux-kernel, syzkaller-bugs, tytso
Hello,
syzbot found the following issue on:
HEAD commit: c330cb607721 Merge tag 'i2c-for-6.17-rc3' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=115a7a34580000
kernel config: https://syzkaller.appspot.com/x/.config?x=292f3bc9f654adeb
dashboard link: https://syzkaller.appspot.com/bug?extid=1713b1aa266195b916c2
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bb57ae49985b/disk-c330cb60.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bac705cd2981/vmlinux-c330cb60.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9817d12458c5/bzImage-c330cb60.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1713b1aa266195b916c2@syzkaller.appspotmail.com
EXT4-fs: no memory for groupinfo slab cache
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 UID: 0 PID: 6121 Comm: syz.1.19 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:199
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 fb 3c ed fe cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000ad37700 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: ffffffff8b7c3b57 RCX: 29738ff3f3108600
RDX: 0000000000000000 RSI: ffffffff8b7c3b57 RDI: 0000000000000003
RBP: ffffffff8b786d59 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47127 R12: 0000000000000000
R13: 0000000000000018 R14: 0000000000000018 R15: 0000000000000001
FS: 00007f0bf6da46c0(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4414b3ff98 CR3: 0000000078296000 CR4: 0000000000350ef0
Call Trace:
<TASK>
__kasan_check_byte+0x12/0x40 mm/kasan/common.c:567
kasan_check_byte include/linux/kasan.h:399 [inline]
lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
xa_destroy+0x59/0x2e0 lib/xarray.c:2390
ext4_mb_avg_fragment_size_destroy fs/ext4/mballoc.c:3659 [inline]
ext4_mb_init+0x136a/0x2860 fs/ext4/mballoc.c:3817
__ext4_fill_super fs/ext4/super.c:5558 [inline]
ext4_fill_super+0x5253/0x6090 fs/ext4/super.c:5728
get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
vfs_get_tree+0x92/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0bf5f9038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f0bf6da3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f0bf6da3ef0 RCX: 00007f0bf5f9038a
RDX: 0000200000000240 RSI: 0000200000000280 RDI: 00007f0bf6da3eb0
RBP: 0000200000000240 R08: 00007f0bf6da3ef0 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000246 R12: 0000200000000280
R13: 00007f0bf6da3eb0 R14: 0000000000000236 R15: 0000200000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:199
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 fb 3c ed fe cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000ad37700 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: ffffffff8b7c3b57 RCX: 29738ff3f3108600
RDX: 0000000000000000 RSI: ffffffff8b7c3b57 RDI: 0000000000000003
RBP: ffffffff8b786d59 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47127 R12: 0000000000000000
R13: 0000000000000018 R14: 0000000000000018 R15: 0000000000000001
FS: 00007f0bf6da46c0(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4414b3ff98 CR3: 0000000078296000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
7: 00
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 66 0f 1f 00 nopw (%rax)
1c: 48 c1 ef 03 shr $0x3,%rdi
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 0f b6 04 07 movzbl (%rdi,%rax,1),%eax <-- trapping instruction
2e: 3c 08 cmp $0x8,%al
30: 0f 92 c0 setb %al
33: e9 fb 3c ed fe jmp 0xfeed3d33
38: cc int3
39: 66 data16
3a: 66 data16
3b: 66 data16
3c: 66 data16
3d: 66 data16
3e: 66 data16
3f: 2e cs
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] [ext4?] general protection fault in xa_destroy
2025-08-24 23:26 [syzbot] [ext4?] general protection fault in xa_destroy syzbot
@ 2025-08-25 1:28 ` Baokun Li
0 siblings, 0 replies; 2+ messages in thread
From: Baokun Li @ 2025-08-25 1:28 UTC (permalink / raw)
To: syzbot
Cc: adilger.kernel, linux-ext4, linux-kernel, syzkaller-bugs, tytso,
Baokun Li, Yang Erkun
On 2025-08-25 07:26, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: c330cb607721 Merge tag 'i2c-for-6.17-rc3' of git://git.ker..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=115a7a34580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=292f3bc9f654adeb
> dashboard link: https://syzkaller.appspot.com/bug?extid=1713b1aa266195b916c2
> compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/bb57ae49985b/disk-c330cb60.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/bac705cd2981/vmlinux-c330cb60.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/9817d12458c5/bzImage-c330cb60.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+1713b1aa266195b916c2@syzkaller.appspotmail.com
>
> EXT4-fs: no memory for groupinfo slab cache
> Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN NOPTI
> KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Thank you for reporting this issue!
This issue was caused by the lack of null-checking logic in
ext4_mb_avg_fragment_size_destroy(), which led to problems in
error path handling. My apologies for this oversight - I will
immediately send out the fix patch.
Thanks,
Baokun
> CPU: 0 UID: 0 PID: 6121 Comm: syz.1.19 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
> RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:199
> Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 fb 3c ed fe cc 66 66 66 66 66 66 2e
> RSP: 0018:ffffc9000ad37700 EFLAGS: 00010016
> RAX: dffffc0000000000 RBX: ffffffff8b7c3b57 RCX: 29738ff3f3108600
> RDX: 0000000000000000 RSI: ffffffff8b7c3b57 RDI: 0000000000000003
> RBP: ffffffff8b786d59 R08: 0000000000000001 R09: 0000000000000000
> R10: dffffc0000000000 R11: fffffbfff1f47127 R12: 0000000000000000
> R13: 0000000000000018 R14: 0000000000000018 R15: 0000000000000001
> FS: 00007f0bf6da46c0(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f4414b3ff98 CR3: 0000000078296000 CR4: 0000000000350ef0
> Call Trace:
> <TASK>
> __kasan_check_byte+0x12/0x40 mm/kasan/common.c:567
> kasan_check_byte include/linux/kasan.h:399 [inline]
> lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
> xa_destroy+0x59/0x2e0 lib/xarray.c:2390
> ext4_mb_avg_fragment_size_destroy fs/ext4/mballoc.c:3659 [inline]
> ext4_mb_init+0x136a/0x2860 fs/ext4/mballoc.c:3817
> __ext4_fill_super fs/ext4/super.c:5558 [inline]
> ext4_fill_super+0x5253/0x6090 fs/ext4/super.c:5728
> get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
> vfs_get_tree+0x92/0x2b0 fs/super.c:1815
> do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
> do_mount fs/namespace.c:4136 [inline]
> __do_sys_mount fs/namespace.c:4347 [inline]
> __se_sys_mount+0x317/0x410 fs/namespace.c:4324
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f0bf5f9038a
> Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f0bf6da3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
> RAX: ffffffffffffffda RBX: 00007f0bf6da3ef0 RCX: 00007f0bf5f9038a
> RDX: 0000200000000240 RSI: 0000200000000280 RDI: 00007f0bf6da3eb0
> RBP: 0000200000000240 R08: 00007f0bf6da3ef0 R09: 0000000000000004
> R10: 0000000000000004 R11: 0000000000000246 R12: 0000200000000280
> R13: 00007f0bf6da3eb0 R14: 0000000000000236 R15: 0000200000000000
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:199
> Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 fb 3c ed fe cc 66 66 66 66 66 66 2e
> RSP: 0018:ffffc9000ad37700 EFLAGS: 00010016
> RAX: dffffc0000000000 RBX: ffffffff8b7c3b57 RCX: 29738ff3f3108600
> RDX: 0000000000000000 RSI: ffffffff8b7c3b57 RDI: 0000000000000003
> RBP: ffffffff8b786d59 R08: 0000000000000001 R09: 0000000000000000
> R10: dffffc0000000000 R11: fffffbfff1f47127 R12: 0000000000000000
> R13: 0000000000000018 R14: 0000000000000018 R15: 0000000000000001
> FS: 00007f0bf6da46c0(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f4414b3ff98 CR3: 0000000078296000 CR4: 0000000000350ef0
> ----------------
> Code disassembly (best guess):
> 0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
> 7: 00
> 8: 90 nop
> 9: 90 nop
> a: 90 nop
> b: 90 nop
> c: 90 nop
> d: 90 nop
> e: 90 nop
> f: 90 nop
> 10: 90 nop
> 11: 90 nop
> 12: 90 nop
> 13: 90 nop
> 14: 90 nop
> 15: 90 nop
> 16: 90 nop
> 17: 90 nop
> 18: 66 0f 1f 00 nopw (%rax)
> 1c: 48 c1 ef 03 shr $0x3,%rdi
> 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
> 27: fc ff df
> * 2a: 0f b6 04 07 movzbl (%rdi,%rax,1),%eax <-- trapping instruction
> 2e: 3c 08 cmp $0x8,%al
> 30: 0f 92 c0 setb %al
> 33: e9 fb 3c ed fe jmp 0xfeed3d33
> 38: cc int3
> 39: 66 data16
> 3a: 66 data16
> 3b: 66 data16
> 3c: 66 data16
> 3d: 66 data16
> 3e: 66 data16
> 3f: 2e cs
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2025-08-25 1:28 UTC | newest]
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2025-08-24 23:26 [syzbot] [ext4?] general protection fault in xa_destroy syzbot
2025-08-25 1:28 ` Baokun Li
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