syzbot


general protection fault in __put_mountpoint

Status: moderation: reported on 2024/12/22 06:33
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+b905ec40ee9d4a189557@syzkaller.appspotmail.com
First crash: 4d08h, last: 4d08h

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc000000001a: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000000d0-0x00000000000000d7]
CPU: 1 UID: 0 PID: 11093 Comm: syz.2.1329 Tainted: G     U             6.13.0-rc3-syzkaller-00026-g59dbb9d81adf #0
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
RIP: 0010:__lock_acquire+0xe4/0x3c40 kernel/locking/lockdep.c:5089
Code: 08 84 d2 0f 85 15 14 00 00 44 8b 0d 3a 0a a7 0e 45 85 c9 0f 84 b4 0e 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 96 2c 00 00 49 8b 04 24 48 3d a0 67 32 93 0f 84
RSP: 0018:ffffc90003457840 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000001a RSI: 1ffff9200068af1a RDI: 00000000000000d0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff901cddd7 R11: 0000000000000003 R12: 00000000000000d0
R13: ffff888024913c00 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b300c8ff8 CR3: 000000007ea5c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __put_mountpoint.part.0+0x74/0x1c0 fs/namespace.c:949
 __put_mountpoint fs/namespace.c:946 [inline]
 put_mountpoint fs/namespace.c:961 [inline]
 umount_mnt fs/namespace.c:1012 [inline]
 umount_tree+0x7f9/0xde0 fs/namespace.c:1803
 drop_collected_mounts fs/namespace.c:2223 [inline]
 put_mnt_ns fs/namespace.c:5679 [inline]
 put_mnt_ns+0xcb/0x130 fs/namespace.c:5675
 free_nsproxy+0x47/0x470 kernel/nsproxy.c:193
 put_nsproxy include/linux/nsproxy.h:118 [inline]
 switch_task_namespaces+0xeb/0x100 kernel/nsproxy.c:251
 do_exit+0xad8/0x2d70 kernel/exit.c:937
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x2576/0x2610 kernel/signal.c:3017
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7a20385d29
Code: Unable to access opcode bytes at 0x7f7a20385cff.
RSP: 002b:00007f7a211940e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7a20576088 RCX: 00007f7a20385d29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7a20576088
RBP: 00007f7a20576080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a2057608c
R13: 0000000000000000 R14: 00007ffce98c1400 R15: 00007ffce98c14e8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0xe4/0x3c40 kernel/locking/lockdep.c:5089
Code: 08 84 d2 0f 85 15 14 00 00 44 8b 0d 3a 0a a7 0e 45 85 c9 0f 84 b4 0e 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 96 2c 00 00 49 8b 04 24 48 3d a0 67 32 93 0f 84
RSP: 0018:ffffc90003457840 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000001a RSI: 1ffff9200068af1a RDI: 00000000000000d0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff901cddd7 R11: 0000000000000003 R12: 00000000000000d0
R13: ffff888024913c00 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b300c8ff8 CR3: 000000007ea5c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	08 84 d2 0f 85 15 14 	or     %al,0x1415850f(%rdx,%rdx,8)
   7:	00 00                	add    %al,(%rax)
   9:	44 8b 0d 3a 0a a7 0e 	mov    0xea70a3a(%rip),%r9d        # 0xea70a4a
  10:	45 85 c9             	test   %r9d,%r9d
  13:	0f 84 b4 0e 00 00    	je     0xecd
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	4c 89 e2             	mov    %r12,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 96 2c 00 00    	jne    0x2cca
  34:	49 8b 04 24          	mov    (%r12),%rax
  38:	48 3d a0 67 32 93    	cmp    $0xffffffff933267a0,%rax
  3e:	0f                   	.byte 0xf
  3f:	84                   	.byte 0x84

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/18 06:22 upstream 59dbb9d81adf a0626d3a .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto general protection fault in __put_mountpoint
* Struck through repros no longer work on HEAD.