syzbot


INFO: rcu detected stall in mod_timer

Status: auto-closed as invalid on 2020/08/10 12:01
Reported-by: syzbot+b74b04dae431ac24a9fd@syzkaller.appspotmail.com
First crash: 853d, last: 808d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in mod_timer 13 662d 849d 0/1 auto-closed as invalid on 2021/01/03 01:48
upstream INFO: rcu detected stall in mod_timer 2 750d 751d 0/22 auto-closed as invalid on 2020/09/07 13:48

Sample crash report:
INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=19520, c=19519, q=1328)
All QSes seen, last rcu_preempt kthread activity 10495 (4295009222-4294998727), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor.1  R  running task    27408 28651   6356 0x0000000c
Call Trace:
 <IRQ>
 sched_show_task kernel/sched/core.c:5168 [inline]
 sched_show_task.cold+0x2e3/0x347 kernel/sched/core.c:5143
 print_other_cpu_stall kernel/rcu/tree.c:1501 [inline]
 check_cpu_stall kernel/rcu/tree.c:1616 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0xd3f/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x91/0xe0 kernel/locking/spinlock.c:192
RSP: 0018:ffff8880aeb07ca8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd1 RBX: 0000000000000282 RCX: 1ffff110140761c9
RDX: dffffc0000000000 RSI: ffff8880a03b0e28 RDI: 0000000000000282
RBP: ffff8880aeb239c0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffff888099c34ab8 R14: 0000000000000000 R15: ffff8880aeb239c0
 __mod_timer kernel/time/timer.c:1026 [inline]
 mod_timer+0x541/0xe70 kernel/time/timer.c:1069
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279
 expire_timers kernel/time/timer.c:1318 [inline]
 __run_timers kernel/time/timer.c:1636 [inline]
 __run_timers kernel/time/timer.c:1604 [inline]
 run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x91/0xe0 kernel/locking/spinlock.c:192
RSP: 0018:ffff888214c5f9b8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd1 RBX: 0000000000000282 RCX: 1ffff110140761c4
RDX: dffffc0000000000 RSI: ffff8880a03b0e00 RDI: 0000000000000282
RBP: ffff88809f8cb9a8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88809f8cb9a8 R14: ffff88809f8cb990 R15: ffff8880935c8180
 spin_unlock_irqrestore include/linux/spinlock.h:372 [inline]
 skb_dequeue+0x129/0x180 net/core/skbuff.c:2818
 nr_kick.part.0+0x365/0x590 net/netrom/nr_out.c:179
 nr_kick net/netrom/nr_out.c:134 [inline]
 nr_output+0x4e9/0x610 net/netrom/nr_out.c:75
 nr_sendmsg+0x7a1/0x920 net/netrom/af_netrom.c:1135
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xc5/0x100 net/socket.c:656
 sock_write_iter+0x22c/0x370 net/socket.c:925
 call_write_iter include/linux/fs.h:1778 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x44e/0x630 fs/read_write.c:482
 vfs_write+0x192/0x4e0 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xf2/0x210 fs/read_write.c:582
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c889
RSP: 002b:00007fdb08a86c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdb08a876d4 RCX: 000000000045c889
RDX: 0000000000000478 RSI: 0000000020000740 RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000cdc R14: 00000000004cf042 R15: 000000000076bf0c
rcu_preempt kthread starved for 10495 jiffies! g19520 c19519 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_preempt     R  running task    29392     8      2 0x80000000
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
chnl_net:caif_netlink_parms(): no params data found
IPVS: ftp: loaded support on port[0] = 21
chnl_net:caif_netlink_parms(): no params data found
IPVS: ftp: loaded support on port[0] = 21
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
bond0: Enslaving bond_slave_0 as an active interface with an up link
bond0: Enslaving bond_slave_1 as an active interface with an up link
chnl_net:caif_netlink_parms(): no params data found
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
IPVS: ftp: loaded support on port[0] = 21
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
bond0: Enslaving bond_slave_0 as an active interface with an up link
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
device hsr_slave_0 entered promiscuous mode
device hsr_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
chnl_net:caif_netlink_parms(): no params data found
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
bond0: Enslaving bond_slave_0 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
device hsr_slave_0 entered promiscuous mode
device hsr_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
chnl_net:caif_netlink_parms(): no params data found
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready
bond0: Enslaving bond_slave_0 as an active interface with an up link
device hsr_slave_0 entered promiscuous mode
device hsr_slave_1 entered promiscuous mode
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
8021q: adding VLAN 0 to HW filter on device bond0
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
device hsr_slave_0 entered promiscuous mode
device hsr_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready
8021q: adding VLAN 0 to HW filter on device team0
bond0: Enslaving bond_slave_0 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bond: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready
device hsr_slave_0 entered promiscuous mode
device hsr_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_team: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_team: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0_to_hsr: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_hsr: link is not ready

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/04/12 12:01 linux-4.14.y 4520f06b03ae 36b0b050 .config log report
ci2-linux-4-14 2020/02/27 01:25 linux-4.14.y 98db2bf27b9e 251aabb7 .config log report