syzbot


general protection fault in kernfs_rename_ns

Status: moderation: reported on 2025/04/25 16:34
Subsystems: kernfs
[Documentation on labels]
Reported-by: syzbot+5f1a7cb1862be0787568@syzkaller.appspotmail.com
First crash: 4d20h, last: 3d12h

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 0 UID: 0 PID: 11644 Comm: syz-executor Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:kernfs_rename_ns+0x3b/0xa50 fs/kernfs/dir.c:1744
Code: 48 89 fb 4c 8d 7b 30 48 83 ec 20 48 89 14 24 48 89 4c 24 08 e8 56 e0 5b ff 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 08 00 00 48 8b 43 30 48 85 c0 0f 84 a6 08 00
RSP: 0018:ffffc90003edf9a8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff825f6f9a RDI: 0000000000000000
RBP: ffff88814368d1e0 R08: 0000000000000007 R09: 0000000000000000
R10: 000000007fffffff R11: 0000000000000000 R12: ffff88802ff137a0
R13: ffff888031e68040 R14: ffff888143681480 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff8881249b2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a9f26533a CR3: 0000000059c9e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kobject_move+0x127/0x260 lib/kobject.c:569
 device_move+0xa9/0x10d0 drivers/base/core.c:4583
 hci_conn_del_sysfs+0x81/0x180 net/bluetooth/hci_sysfs.c:75
 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline]
 hci_conn_del+0x55f/0xdc0 net/bluetooth/hci_conn.c:1167
 hci_conn_hash_flush+0x186/0x260 net/bluetooth/hci_conn.c:2702
 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5225
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2678
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x3ff/0xb70 fs/file_table.c:465
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xafb/0x2c30 kernel/exit.c:953
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1111
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d69f8e169
Code: Unable to access opcode bytes at 0x7f2d69f8e13f.
RSP: 002b:00007ffd2f718e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2d69f8e169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f2d69fee8d0 R08: 00007ffd2f716c07 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000003 R14: 00000000ffffffff R15: 00007ffd2f719020
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kernfs_rename_ns+0x3b/0xa50 fs/kernfs/dir.c:1744
Code: 48 89 fb 4c 8d 7b 30 48 83 ec 20 48 89 14 24 48 89 4c 24 08 e8 56 e0 5b ff 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 08 00 00 48 8b 43 30 48 85 c0 0f 84 a6 08 00
RSP: 0018:ffffc90003edf9a8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff825f6f9a RDI: 0000000000000000
RBP: ffff88814368d1e0 R08: 0000000000000007 R09: 0000000000000000
R10: 000000007fffffff R11: 0000000000000000 R12: ffff88802ff137a0
R13: ffff888031e68040 R14: ffff888143681480 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff8881249b2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f6f0ff8 CR3: 000000001293a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 89 fb             	mov    %rdi,%rbx
   3:	4c 8d 7b 30          	lea    0x30(%rbx),%r15
   7:	48 83 ec 20          	sub    $0x20,%rsp
   b:	48 89 14 24          	mov    %rdx,(%rsp)
   f:	48 89 4c 24 08       	mov    %rcx,0x8(%rsp)
  14:	e8 56 e0 5b ff       	call   0xff5be06f
  19:	4c 89 fa             	mov    %r15,%rdx
  1c:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  23:	fc ff df
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 f7 08 00 00    	jne    0x92b
  34:	48 8b 43 30          	mov    0x30(%rbx),%rax
  38:	48 85 c0             	test   %rax,%rax
  3b:	0f                   	.byte 0xf
  3c:	84                   	.byte 0x84
  3d:	a6                   	cmpsb  %es:(%rdi),%ds:(%rsi)
  3e:	08 00                	or     %al,(%rax)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/23 01:03 upstream bc3372351d0c 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in kernfs_rename_ns
2025/04/21 16:31 net-next 8066e388be48 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce general protection fault in kernfs_rename_ns
* Struck through repros no longer work on HEAD.