syzbot


BUG: unable to handle kernel paging request in z_erofs_decompress_queue

Status: upstream: reported C repro on 2025/01/16 10:37
Reported-by: syzbot+de2a2a9790d5fde70488@syzkaller.appspotmail.com
First crash: 6d00h, last: 6d00h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: unable to handle kernel paging request in z_erofs_decompress_queue C error error 1 640d 812d 0/2 auto-obsoleted due to no activity on 2023/08/20 19:05
upstream KASAN: slab-use-after-free Read in z_erofs_decompress_queue erofs 6 30d 52d 24/28 upstream: reported on 2024/12/01 07:37

Sample crash report:
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
---[ end trace cf2105fa19a4556e ]---
BUG: unable to handle page fault for address: ffffed112437ffff
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23fff2067 P4D 23fff2067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 42 Comm: erofs_worker/1 Tainted: G        W         5.10.233-syzkaller-00881-gfbe98d68b6b3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:z_erofs_decompress_pcluster fs/erofs/zdata.c:1043 [inline]
RIP: 0010:z_erofs_decompress_queue+0x863/0x1d20 fs/erofs/zdata.c:1188
Code: c0 0f 85 db 01 00 00 41 8b 04 24 c1 f8 02 89 c0 48 8b 4c 24 70 4c 8d 3c c1 4d 89 fc 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 04 00 74 08 4c 89 ff e8 4e f4 7e ff 4d 8b 37 4d 85 f6 0f
RSP: 0018:ffffc900006bf7c0 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffea0004843b40 RCX: ffff888121c00000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea0004843b68
RBP: ffffc900006bfd30 R08: dffffc0000000000 R09: fffff9400090876e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1112437ffff
R13: 0000000000000000 R14: ffffea0004843b40 R15: ffff888921bffff8
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed112437ffff CR3: 000000011a965000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 z_erofs_decompressqueue_work fs/erofs/zdata.c:1199 [inline]
 z_erofs_decompressqueue_kthread_work+0x95/0xe0 fs/erofs/zdata.c:896
 kthread_worker_fn+0x48b/0x920 kernel/kthread.c:759
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Modules linked in:
CR2: ffffed112437ffff
---[ end trace cf2105fa19a4556f ]---
RIP: 0010:z_erofs_decompress_pcluster fs/erofs/zdata.c:1043 [inline]
RIP: 0010:z_erofs_decompress_queue+0x863/0x1d20 fs/erofs/zdata.c:1188
Code: c0 0f 85 db 01 00 00 41 8b 04 24 c1 f8 02 89 c0 48 8b 4c 24 70 4c 8d 3c c1 4d 89 fc 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 04 00 74 08 4c 89 ff e8 4e f4 7e ff 4d 8b 37 4d 85 f6 0f
RSP: 0018:ffffc900006bf7c0 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffea0004843b40 RCX: ffff888121c00000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea0004843b68
RBP: ffffc900006bfd30 R08: dffffc0000000000 R09: fffff9400090876e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1112437ffff
R13: 0000000000000000 R14: ffffea0004843b40 R15: ffff888921bffff8
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed112437ffff CR3: 000000011a965000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	c0 0f 85             	rorb   $0x85,(%rdi)
   3:	db 01                	fildl  (%rcx)
   5:	00 00                	add    %al,(%rax)
   7:	41 8b 04 24          	mov    (%r12),%eax
   b:	c1 f8 02             	sar    $0x2,%eax
   e:	89 c0                	mov    %eax,%eax
  10:	48 8b 4c 24 70       	mov    0x70(%rsp),%rcx
  15:	4c 8d 3c c1          	lea    (%rcx,%rax,8),%r15
  19:	4d 89 fc             	mov    %r15,%r12
  1c:	49 c1 ec 03          	shr    $0x3,%r12
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	41 80 3c 04 00       	cmpb   $0x0,(%r12,%rax,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 ff             	mov    %r15,%rdi
  34:	e8 4e f4 7e ff       	call   0xff7ef487
  39:	4d 8b 37             	mov    (%r15),%r14
  3c:	4d 85 f6             	test   %r14,%r14
  3f:	0f                   	.byte 0xf

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/16 10:28 android13-5.10-lts fbe98d68b6b3 968edaf4 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 BUG: unable to handle kernel paging request in z_erofs_decompress_queue
2025/01/16 10:00 android13-5.10-lts fbe98d68b6b3 968edaf4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 BUG: unable to handle kernel paging request in z_erofs_decompress_queue
* Struck through repros no longer work on HEAD.