linux-kernel - [syzbot] [bcachefs?] general protection fault in btree_node_iter_and_journal

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Message-ID: <66fa3eb3.050a0220.6bad9.0030.GAE@google.com>
Date: Sun, 29 Sep 2024 23:01:23 -0700
From: syzbot <syzbot+005ef9aa519f30d97657@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bcachefs?] general protection fault in btree_node_iter_and_journal_peek

Hello,

syzbot found the following issue on:

HEAD commit:    abf2050f51fd Merge tag 'media/v6.12-1' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112f0a80580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bc30a30374b0753
dashboard link: https://syzkaller.appspot.com/bug?extid=005ef9aa519f30d97657
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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-abf2050f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2179ebeade58/vmlinux-abf2050f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f05289b5cf7c/bzImage-abf2050f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+005ef9aa519f30d97657@...kaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.11.0-syzkaller-09959-gabf2050f51fd #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: bcachefs_write_ref bch2_do_invalidates_work
RIP: 0010:bch2_bkey_buf_reassemble fs/bcachefs/bkey_buf.h:27 [inline]
RIP: 0010:btree_node_iter_and_journal_peek+0x260/0x1010 fs/bcachefs/btree_iter.c:886
Code: 4c 24 18 45 89 f0 50 53 41 51 e8 2b b3 00 00 48 83 c4 18 4c 89 ff e8 8f 87 00 00 48 89 c3 49 89 d7 48 c1 e8 03 48 89 44 24 18 <42> 0f b6 04 28 84 c0 4c 89 ea 0f 85 d1 0c 00 00 48 89 5c 24 38 44
RSP: 0018:ffffc900003a6ce0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000ff RDI: ffffc900003a6e94
RBP: ffffc900003a6f70 R08: ffffc900003a6e93 R09: 0000000000000000
R10: ffffc900003a6e80 R11: fffff52000074dd3 R12: ffffc900003a6ee0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b220af5258 CR3: 00000000408ba000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btree_path_down fs/bcachefs/btree_iter.c:914 [inline]
 bch2_btree_path_traverse_one+0x1981/0x2940 fs/bcachefs/btree_iter.c:1169
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 __bch2_btree_iter_peek fs/bcachefs/btree_iter.c:2197 [inline]
 bch2_btree_iter_peek_upto+0xb58/0x6f00 fs/bcachefs/btree_iter.c:2297
 next_lru_key fs/bcachefs/alloc_background.c:2084 [inline]
 bch2_do_invalidates_work+0x8d5/0x2710 fs/bcachefs/alloc_background.c:2118
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/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:bch2_bkey_buf_reassemble fs/bcachefs/bkey_buf.h:27 [inline]
RIP: 0010:btree_node_iter_and_journal_peek+0x260/0x1010 fs/bcachefs/btree_iter.c:886
Code: 4c 24 18 45 89 f0 50 53 41 51 e8 2b b3 00 00 48 83 c4 18 4c 89 ff e8 8f 87 00 00 48 89 c3 49 89 d7 48 c1 e8 03 48 89 44 24 18 <42> 0f b6 04 28 84 c0 4c 89 ea 0f 85 d1 0c 00 00 48 89 5c 24 38 44
RSP: 0018:ffffc900003a6ce0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000ff RDI: ffffc900003a6e94
RBP: ffffc900003a6f70 R08: ffffc900003a6e93 R09: 0000000000000000
R10: ffffc900003a6e80 R11: fffff52000074dd3 R12: ffffc900003a6ee0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2e13f7f96e CR3: 00000000408ba000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	4c 24 18             	rex.WR and $0x18,%al
   3:	45 89 f0             	mov    %r14d,%r8d
   6:	50                   	push   %rax
   7:	53                   	push   %rbx
   8:	41 51                	push   %r9
   a:	e8 2b b3 00 00       	call   0xb33a
   f:	48 83 c4 18          	add    $0x18,%rsp
  13:	4c 89 ff             	mov    %r15,%rdi
  16:	e8 8f 87 00 00       	call   0x87aa
  1b:	48 89 c3             	mov    %rax,%rbx
  1e:	49 89 d7             	mov    %rdx,%r15
  21:	48 c1 e8 03          	shr    $0x3,%rax
  25:	48 89 44 24 18       	mov    %rax,0x18(%rsp)
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	4c 89 ea             	mov    %r13,%rdx
  34:	0f 85 d1 0c 00 00    	jne    0xd0b
  3a:	48 89 5c 24 38       	mov    %rbx,0x38(%rsp)
  3f:	44                   	rex.R


---
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