linux-kernel - [syzbot] [btrfs?] general protection fault in detach_extent_buffer

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Message-ID: <0000000000003e9581061a285b4c@google.com>
Date: Wed, 05 Jun 2024 11:01:32 -0700
From: syzbot <syzbot+f80b066392366b4af85e@...kaller.appspotmail.com>
To: clm@...com, dsterba@...e.com, josef@...icpanda.com, 
	linux-btrfs@...r.kernel.org, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [btrfs?] general protection fault in detach_extent_buffer_folio

Hello,

syzbot found the following issue on:

HEAD commit:    71d7b52cc33b Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10a94aba980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=96fd46a1ee1615e0
dashboard link: https://syzkaller.appspot.com/bug?extid=f80b066392366b4af85e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-71d7b52c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2083371f9b54/vmlinux-71d7b52c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9f8b0934f579/bzImage-71d7b52c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f80b066392366b4af85e@...kaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc000000002a: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000150-0x0000000000000157]
CPU: 0 PID: 111 Comm: kswapd0 Not tainted 6.10.0-rc2-syzkaller-00064-g71d7b52cc33b #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0xe3e/0x3b30 kernel/locking/lockdep.c:5005
Code: 11 00 00 39 05 93 86 1f 12 0f 82 be 05 00 00 ba 01 00 00 00 e9 e4 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 82 1f 00 00 49 81 3c 24 e0 fd e2 92 0f 84 98 f2
RSP: 0018:ffffc90001f96f10 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000002a RSI: ffff888019192440 RDI: 0000000000000150
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff8fe2c157 R11: 0000000000000002 R12: 0000000000000150
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88802c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020202018 CR3: 000000001d6ac000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
 __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:351 [inline]
 detach_extent_buffer_folio+0x33c/0x870 fs/btrfs/extent_io.c:3385
 btrfs_release_extent_buffer_pages+0xaa/0x1b0 fs/btrfs/extent_io.c:3446
 release_extent_buffer+0x240/0x2c0 fs/btrfs/extent_io.c:4074
 try_release_extent_buffer+0x78d/0x9e0 fs/btrfs/extent_io.c:5115
 btree_release_folio+0xbf/0x100 fs/btrfs/disk-io.c:524
 filemap_release_folio+0x1ed/0x280 mm/filemap.c:4173
 shrink_folio_list+0x254a/0x4150 mm/vmscan.c:1394
 evict_folios+0x6e6/0x1bf0 mm/vmscan.c:4553
 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4749
 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4788
 shrink_many mm/vmscan.c:4851 [inline]
 lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
 shrink_node mm/vmscan.c:5910 [inline]
 kswapd_shrink_node mm/vmscan.c:6720 [inline]
 balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0xe3e/0x3b30 kernel/locking/lockdep.c:5005
Code: 11 00 00 39 05 93 86 1f 12 0f 82 be 05 00 00 ba 01 00 00 00 e9 e4 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 82 1f 00 00 49 81 3c 24 e0 fd e2 92 0f 84 98 f2
RSP: 0018:ffffc90001f96f10 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000002a RSI: ffff888019192440 RDI: 0000000000000150
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff8fe2c157 R11: 0000000000000002 R12: 0000000000000150
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88802c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020202018 CR3: 000000001d6ac000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	11 00                	adc    %eax,(%rax)
   2:	00 39                	add    %bh,(%rcx)
   4:	05 93 86 1f 12       	add    $0x121f8693,%eax
   9:	0f 82 be 05 00 00    	jb     0x5cd
   f:	ba 01 00 00 00       	mov    $0x1,%edx
  14:	e9 e4 00 00 00       	jmp    0xfd
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	4c 89 e2             	mov    %r12,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 82 1f 00 00    	jne    0x1fb6
  34:	49 81 3c 24 e0 fd e2 	cmpq   $0xffffffff92e2fde0,(%r12)
  3b:	92
  3c:	0f                   	.byte 0xf
  3d:	84                   	.byte 0x84
  3e:	98                   	cwtl
  3f:	f2                   	repnz


---
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