[syzbot] [net?] INFO: rcu detected stall in rtnl_newlink (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d528014517f2 Revert ".gitignore: ignore *.cover and *.mbx"
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=124db278a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d576750da57ebbb5
dashboard link: https://syzkaller.appspot.com/bug?extid=afb3084a933aa2bdacc6
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15849d08a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13184990a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e5e1d8e2898a/disk-d5280145.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b9c6252b0cf2/vmlinux-d5280145.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ecdc540999f3/bzImage-d5280145.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+afb308...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-...D } 2671 jiffies s: 1489 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5040 Comm: syz-executor363 Not tainted 6.4.0-syzkaller-11478-gd528014517f2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:__lock_acquire+0x46/0x5e20 kernel/locking/lockdep.c:5000
Code: 89 f5 53 48 81 ec 20 01 00 00 48 8b 84 24 58 01 00 00 48 c7 84 24 a0 00 00 00 b3 8a b5 41 48 c7 84 24 a8 00 00 00 18 0e 14 8c <48> c7 84 24 b0 00 00 00 70 d6 65 81 44 89 44 24 08 48 89 44 24 20
RSP: 0018:ffffc900001e0aa8 EFLAGS: 00000082
RAX: 0000000000000000 RBX: 1ffff9200003c187 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8d356d20
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8ea9e517 R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8d356d20 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555555e03300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000600 CR3: 00000000289bd000 CR4: 0000000000350ee0
Call Trace:
<NMI>
</NMI>
<IRQ>
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
debug_objects_fill_pool lib/debugobjects.c:614 [inline]
debug_object_activate+0x128/0x4f0 lib/debugobjects.c:713
debug_hrtimer_activate kernel/time/hrtimer.c:422 [inline]
debug_activate kernel/time/hrtimer.c:477 [inline]
enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1087
__run_hrtimer kernel/time/hrtimer.c:1705 [inline]
__hrtimer_run_queues+0xa65/0xc00 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1098 [inline]
__sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1115
sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1109
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x3c/0x70 kernel/locking/spinlock.c:194
Code: 74 24 10 e8 06 ac 43 f7 48 89 ef e8 de 1b 44 f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 1f d7 35 f7 65 8b 05 50 25 e1 75 85 c0 74 0a 5b 5d c3 e8 ac ef
RSP: 0018:ffffc90003bbecb0 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff23120ac
RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000001
RBP: ffffffff8cadc9c0 R08: 0000000000000001 R09: fffffbfff230b1e0
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000002
R13: 0000000000000002 R14: 00000000000744f0 R15: 00000000000744f0
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
pcpu_alloc+0x882/0x1430 mm/percpu.c:1843
fib6_nh_init+0x524/0x1bd0 net/ipv6/route.c:3613
ip6_route_info_create+0x10f3/0x1980 net/ipv6/route.c:3796
ip6_route_add+0x28/0x150 net/ipv6/route.c:3840
addrconf_prefix_route+0x309/0x520 net/ipv6/addrconf.c:2425
fixup_permanent_addr net/ipv6/addrconf.c:3500 [inline]
addrconf_permanent_addr net/ipv6/addrconf.c:3524 [inline]
addrconf_notify+0x114f/0x19b0 net/ipv6/addrconf.c:3596
notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93
call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962
call_netdevice_notifiers_extack net/core/dev.c:2000 [inline]
call_netdevice_notifiers net/core/dev.c:2014 [inline]
__dev_notify_flags+0x120/0x2d0 net/core/dev.c:8569
dev_change_flags+0x11b/0x170 net/core/dev.c:8607
do_setlink+0x19e2/0x3ae0 net/core/rtnetlink.c:2867
__rtnl_newlink+0xd85/0x1860 net/core/rtnetlink.c:3655
rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3702
rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6424
netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2549
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914
sock_sendmsg_nosec net/socket.c:725 [inline]
sock_sendmsg+0xde/0x190 net/socket.c:748
__sys_sendto+0x254/0x350 net/socket.c:2134
__do_sys_sendto net/socket.c:2146 [inline]
__se_sys_sendto net/socket.c:2142 [inline]
__x64_sys_sendto+0xe1/0x1b0 net/socket.c:2142
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa216946bd6
Code: 48 c7 c0 ff ff ff ff eb b7 66 2e 0f 1f 84 00 00 00 00 00 90 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 72 c3 90 55 48 83 ec 30 44 89 4c 24 2c 4c 89
RSP: 002b:00007ffd1c703708 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fa216a004e0 RCX: 00007fa216946bd6
RDX: 000000000000002c RSI: 00007fa216a00530 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd1c703724 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa216a00530 R14: 0000000000000003 R15: 0000000000000000
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.077 msecs


---
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If the bug is already fixed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
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[syzbot]

syzbot suspects this issue was fixed by commit:

commit e739718444f7bf2fa3d70d101761ad83056ca628
Author: Kuniyuki Iwashima <kun...@amazon.com>
Date: Sat Jul 29 00:07:05 2023 +0000

net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15b26a4d680000
start commit: d528014517f2 Revert ".gitignore: ignore *.cover and *.mbx"
git tree: upstream

kernel config: https://syzkaller.appspot.com/x/.config?x=d576750da57ebbb5
dashboard link: https://syzkaller.appspot.com/bug?extid=afb3084a933aa2bdacc6

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15849d08a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13184990a80000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Hillf Danton]

On Thu, 06 Jul 2023 07:33:55 -0700

> HEAD commit: d528014517f2 Revert ".gitignore: ignore *.cover and *.mbx"
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13184990a80000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d528014517f2

--- x/net/sched/sch_taprio.c
+++ y/net/sched/sch_taprio.c
@@ -991,11 +991,10 @@ first_run:
rcu_assign_pointer(q->current_entry, next);
spin_unlock(&q->current_entry_lock);

- hrtimer_set_expires(&q->advance_timer, end_time);
-
rcu_read_lock();
__netif_schedule(sch);
rcu_read_unlock();
+ hrtimer_forward_now(&q->advance_timer, ns_to_ktime(NSEC_PER_USEC *2));

return HRTIMER_RESTART;
}
--

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+afb308...@syzkaller.appspotmail.com

Tested on:

commit: d5280145 Revert ".gitignore: ignore *.cover and *.mbx"
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=13d5aab1680000
kernel config: https://syzkaller.appspot.com/x/.config?x=53de8828edb29baf
dashboard link: https://syzkaller.appspot.com/bug?extid=afb3084a933aa2bdacc6
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=17530ab1680000

Note: testing is done by a robot and is best-effort only.

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.