syzbot


stack segment fault in kernfs_rename_ns

Status: upstream: reported on 2025/07/20 03:58
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+d1db96f72a452dc9cbd2@syzkaller.appspotmail.com
First crash: 69d, last: 2d00h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth] stack segment fault in kernfs_rename_ns 0 (1) 2025/07/20 03:58

Sample crash report:
Oops: stack segment: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5879 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kernfs_rename_ns+0x3a/0x7a0 fs/kernfs/dir.c:1747
Code: ec 48 48 89 cb 48 89 54 24 10 49 89 f5 49 89 fe 49 bc 00 00 00 00 00 fc ff df e8 41 f0 61 ff 4d 8d 7e 30 4c 89 fd 48 c1 ed 03 <42> 80 7c 25 00 00 74 08 4c 89 ff e8 86 61 c5 ff 49 83 3f 00 0f 84
RSP: 0018:ffffc9000419f580 EFLAGS: 00010206
RAX: ffffffff825dbe0f RBX: 0000000000000000 RCX: ffff888032d68000
RDX: 0000000000000000 RSI: ffff888143adec30 RDI: 0000000000000000
RBP: 0000000000000006 R08: ffff888032d68000 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888143adec30 R14: 0000000000000000 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff888125d18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1cb028000 CR3: 0000000078976000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kobject_move+0x3a5/0x4f0 lib/kobject.c:569
 device_move+0xe0/0x700 drivers/base/core.c:4606
 hci_conn_del_sysfs+0xb8/0x170 net/bluetooth/hci_sysfs.c:75
 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline]
 hci_conn_del+0xc33/0x11b0 net/bluetooth/hci_conn.c:1211
 hci_conn_hash_flush+0x191/0x230 net/bluetooth/hci_conn.c:2600
 hci_dev_close_sync+0xaef/0x1330 net/bluetooth/hci_sync.c:5294
 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline]
 hci_unregister_dev+0x21a/0x510 net/bluetooth/hci_core.c:2715
 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690
 __fput+0x449/0xa70 fs/file_table.c:468
 task_work_run+0x1d1/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6b5/0x2300 kernel/exit.c:961
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fefed38d5fc
Code: Unable to access opcode bytes at 0x7fefed38d5d2.
RSP: 002b:00007ffde747ea00 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007fefed38d5fc
RDX: 0000000000000030 RSI: 00007ffde747eac0 RDI: 00000000000000f9
RBP: 00007ffde747ea6c R08: 0000000000000000 R09: 00007ffde747e777
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000282
R13: 00000000000927c0 R14: 000000000005f37f R15: 00007ffde747eac0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kernfs_rename_ns+0x3a/0x7a0 fs/kernfs/dir.c:1747
Code: ec 48 48 89 cb 48 89 54 24 10 49 89 f5 49 89 fe 49 bc 00 00 00 00 00 fc ff df e8 41 f0 61 ff 4d 8d 7e 30 4c 89 fd 48 c1 ed 03 <42> 80 7c 25 00 00 74 08 4c 89 ff e8 86 61 c5 ff 49 83 3f 00 0f 84
RSP: 0018:ffffc9000419f580 EFLAGS: 00010206
RAX: ffffffff825dbe0f RBX: 0000000000000000 RCX: ffff888032d68000
RDX: 0000000000000000 RSI: ffff888143adec30 RDI: 0000000000000000
RBP: 0000000000000006 R08: ffff888032d68000 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888143adec30 R14: 0000000000000000 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1cacf7e9c CR3: 0000000051c3a000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	ec                   	in     (%dx),%al
   1:	48                   	rex.W
   2:	48 89 cb             	mov    %rcx,%rbx
   5:	48 89 54 24 10       	mov    %rdx,0x10(%rsp)
   a:	49 89 f5             	mov    %rsi,%r13
   d:	49 89 fe             	mov    %rdi,%r14
  10:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
  17:	fc ff df
  1a:	e8 41 f0 61 ff       	call   0xff61f060
  1f:	4d 8d 7e 30          	lea    0x30(%r14),%r15
  23:	4c 89 fd             	mov    %r15,%rbp
  26:	48 c1 ed 03          	shr    $0x3,%rbp
* 2a:	42 80 7c 25 00 00    	cmpb   $0x0,0x0(%rbp,%r12,1) <-- trapping instruction
  30:	74 08                	je     0x3a
  32:	4c 89 ff             	mov    %r15,%rdi
  35:	e8 86 61 c5 ff       	call   0xffc561c0
  3a:	49 83 3f 00          	cmpq   $0x0,(%r15)
  3e:	0f                   	.byte 0xf
  3f:	84                   	.byte 0x84

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/09 17:39 net e3c674db356c d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce stack segment fault in kernfs_rename_ns
2025/08/17 22:06 net 715c7a36d59f 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce stack segment fault in kernfs_rename_ns
2025/08/04 08:46 net 1dbf1d590d10 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce stack segment fault in kernfs_rename_ns
2025/07/06 18:04 net b9fd9888a565 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce stack segment fault in kernfs_rename_ns
2025/08/18 17:09 net-next bab3ce404553 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce stack segment fault in kernfs_rename_ns
2025/07/23 14:56 net-next 56613001dfc9 e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce stack segment fault in kernfs_rename_ns
2025/07/04 21:24 net-next 6b9fd8857b9f d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce stack segment fault in kernfs_rename_ns
2025/07/04 03:26 net-next 5f712c3877f9 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce stack segment fault in kernfs_rename_ns
2025/07/20 03:58 linux-next d086c886ceb9 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root stack segment fault in kernfs_rename_ns
2025/07/15 10:37 linux-next 0be23810e32e 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce stack segment fault in kernfs_rename_ns
* Struck through repros no longer work on HEAD.