syzbot


general protection fault in cache_first_page

Status: upstream: reported on 2023/02/12 02:17
Subsystems: squashfs
[Documentation on labels]
Reported-by: syzbot+400ddff795d51da0f580@syzkaller.appspotmail.com
First crash: 472d, last: 462d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in cache_first_page squashfs C error 4 496d 508d 22/26 fixed on 2023/06/08 14:41

Sample crash report:
squashfs: SQUASHFS error: unable to read xattr id index table
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 17653 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
RIP: 0010:cache_first_page+0x5c/0x90 fs/squashfs/page_actor.c:27
Code: 00 00 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 30 48 b8 00 00 00 00 00 fc ff df 48 8b 1b 48 89 da 48 c1 ea 03 <80> 3c 02 00 75 0c 48 8b 03 5b c3 e8 84 7b a4 ff eb bc 48 89 df e8
RSP: 0018:ffff88804e587a88 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000010 RCX: ffffc90008886000
RDX: 0000000000000002 RSI: ffffffff81f3e8b9 RDI: ffff888092a7e2b0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000001
R13: 00000000000001f8 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f2986956700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1df616000 CR3: 0000000096db6000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 squashfs_first_page fs/squashfs/page_actor.h:70 [inline]
 squashfs_read_data+0xabb/0x13a0 fs/squashfs/block.c:181
 squashfs_read_table+0x184/0x1f0 fs/squashfs/cache.c:445
 squashfs_read_xattr_id_table+0x208/0x440 fs/squashfs/xattr_id.c:108
 squashfs_fill_super+0xcc0/0x1cf0 fs/squashfs/super.c:234
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x310 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2492 [inline]
 do_mount+0x115c/0x2f50 fs/namespace.c:2822
 ksys_mount+0xcf/0x130 fs/namespace.c:3038
 __do_sys_mount fs/namespace.c:3052 [inline]
 __se_sys_mount fs/namespace.c:3049 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3049
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f29883e562a
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 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:00007f2986955f88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000000001cb RCX: 00007f29883e562a
RDX: 0000000020000200 RSI: 0000000020000240 RDI: 00007f2986955fe0
RBP: 00007f2986956020 R08: 00007f2986956020 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000202 R12: 0000000020000200
R13: 0000000020000240 R14: 00007f2986955fe0 R15: 00000000200001c0
Modules linked in:
---[ end trace 7c7f5d91563adb82 ]---
RIP: 0010:cache_first_page+0x5c/0x90 fs/squashfs/page_actor.c:27
Code: 00 00 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 30 48 b8 00 00 00 00 00 fc ff df 48 8b 1b 48 89 da 48 c1 ea 03 <80> 3c 02 00 75 0c 48 8b 03 5b c3 e8 84 7b a4 ff eb bc 48 89 df e8
squashfs: SQUASHFS error: unable to read id index table
RSP: 0018:ffff88804e587a88 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000010 RCX: ffffc90008886000
RDX: 0000000000000002 RSI: ffffffff81f3e8b9 RDI: ffff888092a7e2b0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000001
squashfs: SQUASHFS error: unable to read xattr id index table
R13: 00000000000001f8 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f2986956700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
squashfs: SQUASHFS error: unable to read id index table
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd3c7178000 CR3: 0000000096db6000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   9:	fc ff df
   c:	48 c1 ea 03          	shr    $0x3,%rdx
  10:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  14:	75 30                	jne    0x46
  16:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1d:	fc ff df
  20:	48 8b 1b             	mov    (%rbx),%rbx
  23:	48 89 da             	mov    %rbx,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	75 0c                	jne    0x3c
  30:	48 8b 03             	mov    (%rbx),%rax
  33:	5b                   	pop    %rbx
  34:	c3                   	retq
  35:	e8 84 7b a4 ff       	callq  0xffa47bbe
  3a:	eb bc                	jmp    0xfffffff8
  3c:	48 89 df             	mov    %rbx,%rdi
  3f:	e8                   	.byte 0xe8

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/22 05:58 linux-4.19.y 3f8a27f9e27b 42a4d508 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 general protection fault in cache_first_page
2023/02/12 02:16 linux-4.19.y 3f8a27f9e27b 93e26d60 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 general protection fault in cache_first_page
* Struck through repros no longer work on HEAD.