syzbot


INFO: rcu detected stall in add_key

Status: auto-closed as invalid on 2021/12/08 01:58
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 443d, last: 443d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=94257, q=139)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295019486-4295008984), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g94257 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26768 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xc8d/0x1270 kernel/sched/core.c:6287
 schedule+0x14b/0x210 kernel/sched/core.c:6366
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1957
 rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2130
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 25850 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:217 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x4/0x90 kernel/kcov.c:264
Code: c1 e0 03 48 83 c8 18 48 89 34 01 4c 89 44 f9 18 49 ff c2 4c 89 11 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 4c 8b 04 24 <65> 48 8b 14 25 c0 ef 01 00 65 8b 05 74 75 7f 7e a9 00 01 ff 00 74
RSP: 0018:ffffc90000007c78 EFLAGS: 00000046
RAX: 1ffff1100e27c505 RBX: 1770f6392ee1ec72 RCX: dffffc0000000000
RDX: ffff888075aeb900 RSI: 1770f6392ee1ec72 RDI: 1770f6392ee1ec72
RBP: 1770f6392ee1ec72 R08: ffffffff8840946f R09: 0000000000000003
R10: fffff52000000f81 R11: 0000000000000004 R12: ffff8880713e2828
R13: ffff8880713e2810 R14: ffff88807c941510 R15: 1ffff1100f9282a0
FS:  00007f3103051700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000568000 CR3: 0000000070f14000 CR4: 00000000001506f0
Call Trace:
 <IRQ>
 should_restart_cycle net/sched/sch_taprio.c:661 [inline]
 advance_sched+0x32f/0x930 net/sched/sch_taprio.c:734
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:smack_cred security/smack/smack.h:336 [inline]
RIP: 0010:smack_key_alloc+0x2f/0x90 security/smack/smack_lsm.c:4238
Code: 54 53 49 89 f7 49 89 fe 49 bc 00 00 00 00 00 fc ff df e8 a4 86 ad fd 49 81 c7 88 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 ff e8 f7 dd f8 fd 48 63 1d 60 bb 63 08 49 03 1f 48 89
RSP: 0018:ffffc9000341fb08 EFLAGS: 00000246
RAX: 1ffff1100e1b5ff1 RBX: ffffffff8c38bb38 RCX: 0000000000040000
RDX: ffffc90012216000 RSI: 00000000000010d3 RDI: 00000000000010d4
RBP: ffffffff8c38bb50 R08: ffffffff83cf50af R09: ffff88823bccef20
R10: ffffed1047799de6 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88823bccee80 R15: ffff888070daff88
 security_key_alloc+0x56/0xb0 security/security.c:2520
 key_alloc+0x7c5/0xf10 security/keys/key.c:314
 keyring_alloc+0x40/0xa0 security/keys/keyring.c:526
 install_process_keyring_to_cred security/keys/process_keys.c:275 [inline]
 install_process_keyring security/keys/process_keys.c:300 [inline]
 lookup_user_key+0x4d6/0x1710 security/keys/process_keys.c:653
 __do_sys_add_key security/keys/keyctl.c:126 [inline]
 __se_sys_add_key+0x2f3/0x480 security/keys/keyctl.c:74
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3103051188 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9
RDX: 0000000020000a80 RSI: 0000000020000080 RDI: 0000000020000a40
RBP: 00000000004bfcc4 R08: fffffffffffffffe R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffdfdab915f R14: 00007f3103051300 R15: 0000000000022000
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
   0:	c1 e0 03             	shl    $0x3,%eax
   3:	48 83 c8 18          	or     $0x18,%rax
   7:	48 89 34 01          	mov    %rsi,(%rcx,%rax,1)
   b:	4c 89 44 f9 18       	mov    %r8,0x18(%rcx,%rdi,8)
  10:	49 ff c2             	inc    %r10
  13:	4c 89 11             	mov    %r10,(%rcx)
  16:	c3                   	retq
  17:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
  1e:	00 00 00
  21:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  26:	4c 8b 04 24          	mov    (%rsp),%r8
* 2a:	65 48 8b 14 25 c0 ef 	mov    %gs:0x1efc0,%rdx <-- trapping instruction
  31:	01 00
  33:	65 8b 05 74 75 7f 7e 	mov    %gs:0x7e7f7574(%rip),%eax        # 0x7e7f75ae
  3a:	a9 00 01 ff 00       	test   $0xff0100,%eax
  3f:	74                   	.byte 0x74

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/09/09 01:53 upstream 2d338201d531 e2776ee4 .config log report info INFO: rcu detected stall in add_key
* Struck through repros no longer work on HEAD.