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Date:   Sun, 21 May 2023 04:45:51 -0700
Message-ID: <0000000000002930a705fc32b231@google.com>
Subject: [syzbot] [nilfs?] general protection fault in folio_create_empty_buffers
From:   syzbot <syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com>
To:     konishi.ryusuke@gmail.com, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-nilfs@vger.kernel.org,
        syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    0dd2a6fb1e34 Merge tag 'tty-6.4-rc3' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14343765280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9afc9b1b9107cdcd
dashboard link: https://syzkaller.appspot.com/bug?extid=0ad741797f4565e7e2d2
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1746d572280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/df4d9c4d67a3/disk-0dd2a6fb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/76f164dda927/vmlinux-0dd2a6fb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3f4f63ee8d7e/bzImage-0dd2a6fb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/420107162e49/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com

NILFS (loop1): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
general protection fault, probably for non-canonical address 0xdffffc000000003d: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000001e8-0x00000000000001ef]
CPU: 0 PID: 5383 Comm: segctord Not tainted 6.4.0-rc2-syzkaller-00330-g0dd2a6fb1e34 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
RIP: 0010:__lock_acquire+0xdce/0x5df0 kernel/locking/lockdep.c:4942
Code: 00 00 3b 05 04 82 59 0f 0f 87 42 0a 00 00 41 be 01 00 00 00 e9 83 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 19 32 00 00 48 81 3b 20 08 16 90 0f 84 06 f3 ff
RSP: 0018:ffffc9000549f618 EFLAGS: 00010012
RAX: dffffc0000000000 RBX: 00000000000001e8 RCX: 0000000000000000
RDX: 000000000000003d RSI: 0000000000000000 RDI: 00000000000001e8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802009bb80 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000016b15000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5691 [inline]
 lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:350 [inline]
 folio_create_empty_buffers+0xb0/0x470 fs/buffer.c:1615
 nilfs_lookup_dirty_data_buffers+0x580/0x6f0 fs/nilfs2/segment.c:730
 nilfs_segctor_scan_file+0x1b1/0x6f0 fs/nilfs2/segment.c:1075
 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1197 [inline]
 nilfs_segctor_collect fs/nilfs2/segment.c:1524 [inline]
 nilfs_segctor_do_construct+0x267f/0x7200 fs/nilfs2/segment.c:2070
 nilfs_segctor_construct+0x8e3/0xb30 fs/nilfs2/segment.c:2404
 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2512 [inline]
 nilfs_segctor_thread+0x3c7/0xf30 fs/nilfs2/segment.c:2595
 kthread+0x344/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0xdce/0x5df0 kernel/locking/lockdep.c:4942
Code: 00 00 3b 05 04 82 59 0f 0f 87 42 0a 00 00 41 be 01 00 00 00 e9 83 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 19 32 00 00 48 81 3b 20 08 16 90 0f 84 06 f3 ff
RSP: 0018:ffffc9000549f618 EFLAGS: 00010012
RAX: dffffc0000000000 RBX: 00000000000001e8 RCX: 0000000000000000
RDX: 000000000000003d RSI: 0000000000000000 RDI: 00000000000001e8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802009bb80 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000016b15000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	3b 05 04 82 59 0f    	cmp    0xf598204(%rip),%eax        # 0xf59820c
   8:	0f 87 42 0a 00 00    	ja     0xa50
   e:	41 be 01 00 00 00    	mov    $0x1,%r14d
  14:	e9 83 00 00 00       	jmpq   0x9c
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 da             	mov    %rbx,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 19 32 00 00    	jne    0x324d
  34:	48 81 3b 20 08 16 90 	cmpq   $0xffffffff90160820,(%rbx)
  3b:	0f                   	.byte 0xf
  3c:	84 06                	test   %al,(%rsi)
  3e:	f3                   	repz
  3f:	ff                   	.byte 0xff


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