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

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Message-ID: <67f14ee9.050a0220.0a13.023e.GAE@google.com>
Date: Sat, 05 Apr 2025 08:40:25 -0700
From: syzbot <syzbot+7481815bb47ef3e702e2@...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 relocate_file_extent_cluster

Hello,

syzbot found the following issue on:

HEAD commit:    a8662bcd2ff1 Merge tag 'v6.15-p3' of git://git.kernel.org/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1358efb0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f2054704dd53fb80
dashboard link: https://syzkaller.appspot.com/bug?extid=7481815bb47ef3e702e2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=139e67cf980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10960d78580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-a8662bcd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bd06651979f7/vmlinux-a8662bcd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4ade9d94d78e/bzImage-a8662bcd.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/eb056de8bfc4/mount_0.gz
  fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=16d62b4c580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7481815bb47ef3e702e2@...kaller.appspotmail.com

R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffc55de5790
 </TASK>
BTRFS info (device loop0): relocating block group 6881280 flags data|metadata
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000045: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000228-0x000000000000022f]
CPU: 0 UID: 0 PID: 5332 Comm: syz-executor215 Not tainted 6.14.0-syzkaller-13423-ga8662bcd2ff1 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971
Code: 00 74 08 48 89 df e8 f8 36 24 fe 48 89 9c 24 30 01 00 00 4c 89 74 24 28 4d 8b 76 10 49 8d 9e 98 fe ff ff 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 ca 36 24 fe 4c 8b 3b 48 8b 44 24
RSP: 0018:ffffc9000d3375e0 EFLAGS: 00010203
RAX: 0000000000000045 RBX: 000000000000022c RCX: ffff888000562440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880452db000
RBP: ffffc9000d337870 R08: ffffffff84089251 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffffff9368a020 R14: 0000000000000394 R15: ffff8880452db000
FS:  000055558bc7b380(0000) GS:ffff88808c596000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a7a192e740 CR3: 0000000036e2e000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 relocate_block_group+0xa1e/0xd50 fs/btrfs/relocation.c:3657
 btrfs_relocate_block_group+0x777/0xd80 fs/btrfs/relocation.c:4011
 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3511
 __btrfs_balance+0x1a93/0x25e0 fs/btrfs/volumes.c:4292
 btrfs_balance+0xbde/0x10c0 fs/btrfs/volumes.c:4669
 btrfs_ioctl_balance+0x3f5/0x660 fs/btrfs/ioctl.c:3586
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb4ef537dd9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1b 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc55de5728 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffc55de5750 RCX: 00007fb4ef537dd9
RDX: 0000200000000440 RSI: 00000000c4009420 RDI: 0000000000000003
RBP: 0000000000000002 R08: 00007ffc55de54c6 R09: 00007ffc55de5770
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffc55de5790
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971
Code: 00 74 08 48 89 df e8 f8 36 24 fe 48 89 9c 24 30 01 00 00 4c 89 74 24 28 4d 8b 76 10 49 8d 9e 98 fe ff ff 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 ca 36 24 fe 4c 8b 3b 48 8b 44 24
RSP: 0018:ffffc9000d3375e0 EFLAGS: 00010203
RAX: 0000000000000045 RBX: 000000000000022c RCX: ffff888000562440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880452db000
RBP: ffffc9000d337870 R08: ffffffff84089251 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffffff9368a020 R14: 0000000000000394 R15: ffff8880452db000
FS:  000055558bc7b380(0000) GS:ffff88808c596000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a7a192e740 CR3: 0000000036e2e000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 74 08 48          	add    %dh,0x48(%rax,%rcx,1)
   4:	89 df                	mov    %ebx,%edi
   6:	e8 f8 36 24 fe       	call   0xfe243703
   b:	48 89 9c 24 30 01 00 	mov    %rbx,0x130(%rsp)
  12:	00
  13:	4c 89 74 24 28       	mov    %r14,0x28(%rsp)
  18:	4d 8b 76 10          	mov    0x10(%r14),%r14
  1c:	49 8d 9e 98 fe ff ff 	lea    -0x168(%r14),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 ca 36 24 fe       	call   0xfe243703
  39:	4c 8b 3b             	mov    (%rbx),%r15
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	44                   	rex.R
  3f:	24                   	.byte 0x24


---
This report is generated by a bot. It may contain errors.
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