syzbot


general protection fault in pick_link

Status: upstream: reported C repro on 2024/11/14 18:08
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+73d8fc29ec7cba8286fa@syzkaller.appspotmail.com
First crash: 7d07h, last: 7d04h
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] fs: add check for symlink corrupted 8 (8) 2024/11/16 02:32
[syzbot] [ntfs3?] general protection fault in pick_link 0 (2) 2024/11/15 08:26
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in pick_link squashfs C 9 105d 109d 28/28 fixed on 2024/10/03 15:25
upstream KMSAN: kernel-infoleak in _copy_to_iter (8) mm C 21180 528d 622d 22/28 fixed on 2023/06/08 14:41
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/11/15 08:26 20m lizhi.xu@windriver.com patch upstream OK log

Sample crash report:
loop0: detected capacity change from 0 to 4096
ntfs3(loop0): Different NTFS sector size (4096) and media sector size (512).
ntfs3(loop0): ino=1b, "file0" attr_set_size
ntfs3(loop0): Mark volume as dirty due to NTFS errors
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: 5310 Comm: syz-executor255 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:pick_link+0x51c/0xd50 fs/namei.c:1864
Code: c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 fc 00 e9 ff 48 8b 2b 48 85 ed 0f 84 92 00 00 00 e8 7b 36 7f ff 48 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 a2 05 00 00 0f b6 5d 00 bf 2f 00 00 00
RSP: 0018:ffffc9000d147998 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88804558dec8 RCX: ffff88801ec7a440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff8215a35f R09: 1ffffffff203a13d
R10: dffffc0000000000 R11: fffffbfff203a13e R12: 1ffff92001a28f93
R13: ffffc9000d147af8 R14: 1ffff92001a28f5f R15: dffffc0000000000
FS:  0000555577611380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcc0a595ed8 CR3: 0000000035760000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 step_into+0xca9/0x1080 fs/namei.c:1923
 lookup_last fs/namei.c:2556 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2580
 filename_lookup+0x256/0x610 fs/namei.c:2609
 user_path_at+0x3a/0x60 fs/namei.c:3016
 do_mount fs/namespace.c:3844 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x297/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b18ad5b19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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:00007ffc2e486c48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f4b18ad5b19
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000000
RBP: 00007f4b18b685f0 R08: 0000000000000000 R09: 00005555776124c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc2e486c70
R13: 00007ffc2e486e98 R14: 431bde82d7b634db R15: 00007f4b18b1e03b
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pick_link+0x51c/0xd50 fs/namei.c:1864
Code: c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 fc 00 e9 ff 48 8b 2b 48 85 ed 0f 84 92 00 00 00 e8 7b 36 7f ff 48 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 a2 05 00 00 0f b6 5d 00 bf 2f 00 00 00
RSP: 0018:ffffc9000d147998 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88804558dec8 RCX: ffff88801ec7a440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff8215a35f R09: 1ffffffff203a13d
R10: dffffc0000000000 R11: fffffbfff203a13e R12: 1ffff92001a28f93
R13: ffffc9000d147af8 R14: 1ffff92001a28f5f R15: dffffc0000000000
FS:  0000555577611380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcc0a595ed8 CR3: 0000000035760000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	c1 e8 03             	shr    $0x3,%eax
   3:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
   8:	74 08                	je     0x12
   a:	48 89 df             	mov    %rbx,%rdi
   d:	e8 fc 00 e9 ff       	call   0xffe9010e
  12:	48 8b 2b             	mov    (%rbx),%rbp
  15:	48 85 ed             	test   %rbp,%rbp
  18:	0f 84 92 00 00 00    	je     0xb0
  1e:	e8 7b 36 7f ff       	call   0xff7f369e
  23:	48 89 e8             	mov    %rbp,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 a2 05 00 00    	jne    0x5d9
  37:	0f b6 5d 00          	movzbl 0x0(%rbp),%ebx
  3b:	bf 2f 00 00 00       	mov    $0x2f,%edi

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/10 21:10 upstream a9cda7c0ffed 6b856513 .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 pick_link
2024/11/10 20:37 upstream a9cda7c0ffed 6b856513 .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 pick_link
2024/11/10 18:00 upstream de2f378f2b77 6b856513 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in pick_link
* Struck through repros no longer work on HEAD.