syzbot


general protection fault in btrfs_lookup_csums_bitmap

Status: upstream: reported C repro on 2024/10/23 09:08
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+5d2b33d7835870519b5f@syzkaller.appspotmail.com
First crash: 250d, last: 54d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] btrfs: add a sanity check for csum root before fill the data csum 5 (5) 2024/10/29 20:55
[syzbot] [btrfs?] general protection fault in btrfs_lookup_csums_bitmap 1 (3) 2024/10/23 10:38
Last patch testing requests (7)
Created Duration User Patch Repo Result
2025/06/01 19:26 20m retest repro upstream OK log
2025/05/17 05:20 20m retest repro upstream OK log
2025/03/23 18:52 15m retest repro upstream report log
2025/02/27 05:40 19m retest repro upstream report log
2025/01/11 10:50 13m retest repro upstream report log
2024/11/02 10:28 13m retest repro upstream report log
2024/10/23 10:18 19m eadavis@qq.com patch upstream OK log

Sample crash report:
loop0: detected capacity change from 0 to 32768
BTRFS: device fsid a6a605fc-d5f1-4e66-8595-3726e2b761d6 devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5315)
BTRFS info (device loop0 state S): first mount of filesystem a6a605fc-d5f1-4e66-8595-3726e2b761d6
BTRFS info (device loop0 state S): using blake2b (blake2b-256-generic) checksum algorithm
BTRFS info (device loop0 state S): using free-space-tree
BTRFS warning (device loop0 state CS): mismatching generation and generation_v2 found in root item. This root was probably mounted with an older kernel. Resetting all new fields.
BTRFS error (device loop0 state CS): block group 6881280 len 1638400 type flags 0x2 mismatch with chunk type flags 0x5
BTRFS info (device loop0 state CS): scrub: started on devid 1
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000041: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000208-0x000000000000020f]
CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted 6.15.0-rc4-syzkaller-00208-g00b827f0cffa #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:btrfs_lookup_csums_bitmap+0xc3/0x11b0 fs/btrfs/file-item.c:610
Code: 8c 24 90 00 00 00 42 c7 44 21 08 f3 f3 f3 f3 e8 13 a4 02 fe 48 89 9c 24 80 00 00 00 48 81 c3 08 02 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 be 98 64 fe 48 8b 03 48 89 44 24
RSP: 0018:ffffc9000d397220 EFLAGS: 00010206
RAX: 0000000000000041 RBX: 0000000000000208 RCX: 0000000000100000
RDX: ffffc9000e1c2000 RSI: 0000000000015d61 RDI: 0000000000015d62
RBP: ffffc9000d397390 R08: ffff888011aa2c00 R09: ffffc9000d3974a0
R10: dffffc0000000000 R11: ffffed100a4f402e R12: dffffc0000000000
R13: 1ffff1100a4f4016 R14: 0000000000500000 R15: 0000000000500000
FS:  00007fc2b3d916c0(0000) GS:ffff88808d6cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b90397c028 CR3: 0000000040694000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 scrub_find_fill_first_stripe+0xca1/0xff0 fs/btrfs/scrub.c:1622
 queue_scrub_stripe fs/btrfs/scrub.c:1925 [inline]
 scrub_simple_mirror+0x648/0xa20 fs/btrfs/scrub.c:2156
 scrub_stripe+0xa11/0x2790 fs/btrfs/scrub.c:2321
 scrub_chunk+0x2a3/0x430 fs/btrfs/scrub.c:2447
 scrub_enumerate_chunks+0xa35/0x11b0 fs/btrfs/scrub.c:2711
 btrfs_scrub_dev+0x732/0xd50 fs/btrfs/scrub.c:3033
 btrfs_ioctl_scrub+0x228/0x360 fs/btrfs/ioctl.c:3164
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc2b2f8e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc2b3d91038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc2b31b5fa0 RCX: 00007fc2b2f8e969
RDX: 0000200000000000 RSI: 00000000c400941b RDI: 0000000000000004
RBP: 00007fc2b3010ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc2b31b5fa0 R15: 00007fff2a628ed8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:btrfs_lookup_csums_bitmap+0xc3/0x11b0 fs/btrfs/file-item.c:610
Code: 8c 24 90 00 00 00 42 c7 44 21 08 f3 f3 f3 f3 e8 13 a4 02 fe 48 89 9c 24 80 00 00 00 48 81 c3 08 02 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 be 98 64 fe 48 8b 03 48 89 44 24
RSP: 0018:ffffc9000d397220 EFLAGS: 00010206
RAX: 0000000000000041 RBX: 0000000000000208 RCX: 0000000000100000
RDX: ffffc9000e1c2000 RSI: 0000000000015d61 RDI: 0000000000015d62
RBP: ffffc9000d397390 R08: ffff888011aa2c00 R09: ffffc9000d3974a0
R10: dffffc0000000000 R11: ffffed100a4f402e R12: dffffc0000000000
R13: 1ffff1100a4f4016 R14: 0000000000500000 R15: 0000000000500000
FS:  00007fc2b3d916c0(0000) GS:ffff88808d6cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b90397c028 CR3: 0000000040694000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	8c 24 90             	mov    %fs,(%rax,%rdx,4)
   3:	00 00                	add    %al,(%rax)
   5:	00 42 c7             	add    %al,-0x39(%rdx)
   8:	44 21 08             	and    %r9d,(%rax)
   b:	f3 f3 f3 f3 e8 13 a4 	repz repz repz repz call 0xfe02a427
  12:	02 fe
  14:	48 89 9c 24 80 00 00 	mov    %rbx,0x80(%rsp)
  1b:	00
  1c:	48 81 c3 08 02 00 00 	add    $0x208,%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 be 98 64 fe       	call   0xfe6498f7
  39:	48 8b 03             	mov    (%rbx),%rax
  3c:	48                   	rex.W
  3d:	89                   	.byte 0x89
  3e:	44                   	rex.R
  3f:	24                   	.byte 0x24

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/03 04:51 upstream 00b827f0cffa b0714e37 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2025/03/09 17:05 upstream 1110ce6a1e34 163f510d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2025/02/13 05:23 upstream 4dc1d1bec898 2afad16e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2025/02/09 09:18 upstream 9946eaf552b1 ef44b750 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2025/02/09 07:31 upstream 9946eaf552b1 ef44b750 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2024/11/12 04:04 upstream 2d5404caa8c7 75bb1b32 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2024/10/19 10:25 upstream b04ae0f45168 cd6fc0a3 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2024/10/19 08:58 upstream b04ae0f45168 cd6fc0a3 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in btrfs_lookup_csums_bitmap
2025/03/23 22:33 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a2392f333575 4e8d3850 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in btrfs_lookup_csums_bitmap
2024/12/02 04:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 7b1d1d4cfac0 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in btrfs_lookup_csums_bitmap
* Struck through repros no longer work on HEAD.