INFO: rcu detected stall in do_signal (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=106c7fdab00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=b092ac47b6897ab77774
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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+b092ac...@syzkaller.appspotmail.com

bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
rcu: 1-....: (10436 ticks this GP) idle=bf6/1/0x4000000000000004 softirq=72533/72676 fqs=3782
rcu: (detected by 0, t=10503 jiffies, g=5293, q=1)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 30954 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unwind_next_frame+0xef5/0x1400 arch/x86/kernel/unwind_orc.c:579
Code: d0 0f 93 c1 49 39 d4 0f 92 c0 84 c1 74 0b 48 3b 6c 24 18 0f 86 5f 01 00 00 bf 01 00 00 00 e8 f2 dc 17 00 65 8b 15 6b 4f d8 7e <85> d2 b8 01 00 00 00 0f 85 90 f1 ff ff e8 23 ad d6 ff e9 86 f1 ff
RSP: 0018:ffff8880ba106ec0 EFLAGS: 00000213
RAX: 0000000000000102 RBX: 1ffff11017420de1 RCX: 0000000000000000
RDX: 0000000000000101 RSI: ffff8880ba106e50 RDI: 0000000000000001
RBP: ffff8880ba107fb0 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8880ba10704f R11: 0000000000074071 R12: ffff8880ba100000
R13: ffff8880ba107025 R14: ffff8880ba106ff0 R15: ffffffff8c11cfdc
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c01c889000 CR3: 0000000052157000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__save_stack_trace+0x9f/0x190 arch/x86/kernel/stacktrace.c:44
save_stack mm/kasan/kasan.c:448 [inline]
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553
slab_post_alloc_hook mm/slab.h:445 [inline]
slab_alloc mm/slab.c:3397 [inline]
kmem_cache_alloc_trace+0x11a/0x380 mm/slab.c:3623
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
nf_bridge_alloc include/net/netfilter/br_netfilter.h:9 [inline]
nf_bridge_unshare net/bridge/br_netfilter_hooks.c:154 [inline]
br_nf_forward_ip+0x34d/0x15e0 net/bridge/br_netfilter_hooks.c:577
nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:511
nf_hook include/linux/netfilter.h:244 [inline]
NF_HOOK include/linux/netfilter.h:287 [inline]
__br_forward+0x354/0xae0 net/bridge/br_forward.c:113
deliver_clone net/bridge/br_forward.c:129 [inline]
br_flood+0x3c2/0x4d0 net/bridge/br_forward.c:238
br_handle_frame_finish+0xf41/0x1410 net/bridge/br_input.c:167
br_nf_hook_thresh+0x2a3/0x330 net/bridge/br_netfilter_hooks.c:1014
br_nf_pre_routing_finish_ipv6+0x6e3/0xd40 net/bridge/br_netfilter_ipv6.c:210
NF_HOOK include/linux/netfilter.h:289 [inline]
br_nf_pre_routing_ipv6+0x3f4/0x860 net/bridge/br_netfilter_ipv6.c:240
br_nf_pre_routing+0xf05/0x1500 net/bridge/br_netfilter_hooks.c:494
nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:511
nf_hook include/linux/netfilter.h:244 [inline]
NF_HOOK include/linux/netfilter.h:287 [inline]
br_handle_frame+0xa60/0x13b0 net/bridge/br_input.c:306
__netif_receive_skb_core+0x929/0x3270 net/core/dev.c:4876
__netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:4952
__netif_receive_skb+0x27/0x1c0 net/core/dev.c:5066
process_backlog+0x241/0x700 net/core/dev.c:5849
napi_poll net/core/dev.c:6280 [inline]
net_rx_action+0x4ac/0xfb0 net/core/dev.c:6346
__do_softirq+0x265/0x980 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:372 [inline]
irq_exit+0x215/0x260 kernel/softirq.c:412
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x47/0x50 kernel/kcov.c:111
Code: 90 60 13 00 00 83 fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 <c3> 0f 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 25 c0 df
RSP: 0018:ffff88809f567738 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff88804d08a100 RBX: 0000000000000000 RCX: ffffffff818ba030
RDX: 0000000000000000 RSI: ffffffff81903332 RDI: ffffea0002cce3c0
RBP: ffffea0002cce3c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dead000000000100
R13: ffffea0002cce3c0 R14: dffffc0000000000 R15: 00007f0ef75cd000
__read_once_size include/linux/compiler.h:263 [inline]
compound_head include/linux/page-flags.h:142 [inline]
PageAnon include/linux/page-flags.h:418 [inline]
page_remove_rmap+0x12/0x120 mm/rmap.c:1296
zap_pte_range mm/memory.c:1350 [inline]
zap_pmd_range mm/memory.c:1463 [inline]
zap_pud_range mm/memory.c:1492 [inline]
zap_p4d_range mm/memory.c:1513 [inline]
unmap_page_range+0x147d/0x2c50 mm/memory.c:1534
unmap_single_vma+0x198/0x300 mm/memory.c:1579
unmap_vmas+0xa9/0x180 mm/memory.c:1609
exit_mmap+0x2b9/0x530 mm/mmap.c:3093
__mmput kernel/fork.c:1016 [inline]
mmput+0x14e/0x4a0 kernel/fork.c:1037
exit_mm kernel/exit.c:549 [inline]
do_exit+0xaec/0x2be0 kernel/exit.c:857
do_group_exit+0x125/0x310 kernel/exit.c:967
get_signal+0x3f2/0x1f70 kernel/signal.c:2589
do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f0ef97beae9
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:00007f0ef6d13188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffff RBX: 00007f0ef98d2020 RCX: 00007f0ef97beae9
RDX: 04000000000000a8 RSI: 00000000200038c0 RDI: 0000000000000007
RBP: 00007f0ef9818f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff8958d07f R14: 00007f0ef6d13300 R15: 0000000000022000
rcu: rcu_sched kthread starved for 1150 jiffies! g5293 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_sched R running task 29760 11 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
net_ratelimit: 110 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
net_ratelimit: 62 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:79:04:22:a4:26, vlan:0)
----------------
Code disassembly (best guess):
0: d0 0f rorb (%rdi)
2: 93 xchg %eax,%ebx
3: c1 49 39 d4 rorl $0xd4,0x39(%rcx)
7: 0f 92 c0 setb %al
a: 84 c1 test %al,%cl
c: 74 0b je 0x19
e: 48 3b 6c 24 18 cmp 0x18(%rsp),%rbp
13: 0f 86 5f 01 00 00 jbe 0x178
19: bf 01 00 00 00 mov $0x1,%edi
1e: e8 f2 dc 17 00 callq 0x17dd15
23: 65 8b 15 6b 4f d8 7e mov %gs:0x7ed84f6b(%rip),%edx # 0x7ed84f95
* 2a: 85 d2 test %edx,%edx <-- trapping instruction
2c: b8 01 00 00 00 mov $0x1,%eax
31: 0f 85 90 f1 ff ff jne 0xfffff1c7
37: e8 23 ad d6 ff callq 0xffd6ad5f
3c: e9 .byte 0xe9
3d: 86 f1 xchg %dh,%cl
3f: ff .byte 0xff


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.