syzbot


general protection fault in pick_link

Status: upstream: reported C repro on 2025/08/10 02:23
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+069d26bb737cfa9917ee@syzkaller.appspotmail.com
First crash: 18d, last: 18d
Bug presence (1)
Date Name Commit Repro Result
2025/08/10 upstream (ToT) 8f5ae30d69d7 C [report] WARNING in ni_rename
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in pick_link (2) ntfs3 2 C error 7 58d 72d 28/29 upstream: reported C repro on 2025/06/17 08:01
upstream KMSAN: uninit-value in pick_link squashfs 7 C 9 389d 393d 28/29 fixed on 2024/10/03 15:25
upstream general protection fault in pick_link ntfs3 2 C 5 136d 286d 28/29 fixed on 2025/05/06 15:33
upstream KMSAN: kernel-infoleak in _copy_to_iter (8) mm 23 C 21180 812d 906d 22/29 fixed on 2023/06/08 14:41

Sample crash report:
         option from the mount to silence this warning.
=======================================================
ntfs3: loop0: ino=3, Correct links count -> 2.
ntfs3: loop0: Mark volume as dirty due to NTFS errors
ntfs3: loop0: ino=1b, "file0" ntfs_rename
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 5946 Comm: syz.0.17 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pick_link+0x52d/0xdd0 fs/namei.c:1813
Code: cd ec ff 4d 8b 2e 4d 85 ed 0f 84 a3 00 00 00 e8 09 87 95 ff 49 bf 00 00 00 00 00 fc ff df 4c 8b 74 24 20 4c 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 12 06 00 00 41 0f b6 6d 00 bf 2f 00 00
RSP: 0018:ffffc90003447848 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc90003447968 RCX: ffff88807b9d0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88807b9d0000 R09: 0000000000000002
R10: 000000003b9aca00 R11: 0000000000000000 R12: 1ffff92000688f93
R13: 0000000000000002 R14: ffffc90003447cc0 R15: dffffc0000000000
FS:  00005555952a8500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d163fff CR3: 0000000026244000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 step_into+0xc3d/0xf10 fs/namei.c:1872
 open_last_lookups fs/namei.c:3579 [inline]
 path_openat+0x16bb/0x3190 fs/namei.c:3786
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_open fs/open.c:1442 [inline]
 __se_sys_open fs/open.c:1438 [inline]
 __x64_sys_open+0x11f/0x140 fs/open.c:1438
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4f1cd8ebe9
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:00007ffccc8d3a08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f4f1cfb5fa0 RCX: 00007f4f1cd8ebe9
RDX: 0000000000000000 RSI: 0000000000048500 RDI: 0000200000000a80
RBP: 00007f4f1ce11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f1cfb5fa0 R14: 00007f4f1cfb5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pick_link+0x52d/0xdd0 fs/namei.c:1813
Code: cd ec ff 4d 8b 2e 4d 85 ed 0f 84 a3 00 00 00 e8 09 87 95 ff 49 bf 00 00 00 00 00 fc ff df 4c 8b 74 24 20 4c 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 12 06 00 00 41 0f b6 6d 00 bf 2f 00 00
RSP: 0018:ffffc90003447848 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc90003447968 RCX: ffff88807b9d0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88807b9d0000 R09: 0000000000000002
R10: 000000003b9aca00 R11: 0000000000000000 R12: 1ffff92000688f93
R13: 0000000000000002 R14: ffffc90003447cc0 R15: dffffc0000000000
FS:  00005555952a8500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d163fff CR3: 0000000026244000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	cd ec                	int    $0xec
   2:	ff 4d 8b             	decl   -0x75(%rbp)
   5:	2e 4d 85 ed          	cs test %r13,%r13
   9:	0f 84 a3 00 00 00    	je     0xb2
   f:	e8 09 87 95 ff       	call   0xff95871d
  14:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  1b:	fc ff df
  1e:	4c 8b 74 24 20       	mov    0x20(%rsp),%r14
  23:	4c 89 e8             	mov    %r13,%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 12 06 00 00    	jne    0x649
  37:	41 0f b6 6d 00       	movzbl 0x0(%r13),%ebp
  3c:	bf                   	.byte 0xbf
  3d:	2f                   	(bad)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/10 05:38 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan general protection fault in pick_link
2025/08/10 02:22 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan general protection fault in pick_link
* Struck through repros no longer work on HEAD.