Hello,
syzbot found the following issue on:
HEAD commit: 12522281 Linux 4.19.182
git tree: linux-4.19.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=15c5573ad00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=2211c6daad8bbe0
dashboard link:
https://syzkaller.appspot.com/bug?extid=ac22ddb8d624dc741fad
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+ac22dd...@syzkaller.appspotmail.com
wlan1: RX AssocResp from 08:02:11:00:00:00 (capab=0x1 status=0 aid=1)
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
wlan1: associated
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10502 jiffies, g=30917, q=142)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294974056-4294963554), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor.4 R running task 27248 15948 8132 0x00000000
Call Trace:
<IRQ>
sched_show_task.cold+0x332/0x396 kernel/sched/core.c:5337
print_other_cpu_stall kernel/rcu/tree.c:1430 [inline]
check_cpu_stall kernel/rcu/tree.c:1557 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold+0xb37/0xe19 kernel/rcu/tree.c:2682
update_process_times+0x2a/0x70 kernel/time/timer.c:1650
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168
tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1419 [inline]
__hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1481
hrtimer_interrupt+0x326/0x9e0 kernel/time/hrtimer.c:1539
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1071 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1096
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:kfree+0x123/0x210 mm/slab.c:3823
Code: 89 ea 48 89 ee 4c 89 e7 e8 da ee ff ff f6 c7 02 74 ca e8 00 94 cf ff 48 83 3d 60 93 59 08 00 0f 84 eb 00 00 00 48 89 df 57 9d <0f> 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05 2a 92 69 7e 83 f8 07
RSP: 0018:ffff8880569c78e8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: 0000000000000286 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000286
RBP: ffff88809e883c00 R08: 0000000000400000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88813bff01c0
R13: ffffffff83b791e7 R14: fffffffffffffff5 R15: 0000000000400043
tty_free_file drivers/tty/tty_io.c:220 [inline]
tty_open+0x5a7/0x990 drivers/tty/tty_io.c:2032
chrdev_open+0x266/0x770 fs/char_dev.c:423
do_dentry_open+0x4aa/0x1160 fs/open.c:796
do_last fs/namei.c:3421 [inline]
path_openat+0x793/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x466459
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:00007fc3fe110188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 0000000000000802 RSI: 0000000020000840 RDI: ffffffffffffff9c
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007fff13953f6f R14: 00007fc3fe110300 R15: 0000000000022000
rcu: rcu_preempt kthread starved for 10502 jiffies! g30917 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 29208 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
schedule_timeout+0x4cf/0xfe0 kernel/time/timer.c:1818
rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
---
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