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INFO: rcu detected stall in userfaultfd_ioctl (2)

Status: auto-obsoleted due to no activity on 2025/04/11 08:39
Subsystems: cgroups mm
[Documentation on labels]
First crash: 180d, last: 180d
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in userfaultfd_ioctl mm 1 1 393d 393d 0/29 auto-obsoleted due to no activity on 2024/09/09 20:59
linux-5.15 INFO: rcu detected stall in userfaultfd_ioctl 1 1 370d 370d 0/3 auto-obsoleted due to no activity on 2024/10/12 17:09

Sample crash report:
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5895/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=9889, q=943 ncpus=2)
task:syz.1.2         state:R  running task     stack:24600 pid:5895  tgid:5893  ppid:5851   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1850/0x4c30 kernel/sched/core.c:6756
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x13b/0x190
Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900042cf418 EFLAGS: 00000206
RAX: 55d4e6d2b6854500 RBX: 0000000000000000 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5fb0a0
RBP: 0000000000000003 R08: ffffffff942a5887 R09: 1ffffffff2854b10
R10: dffffc0000000000 R11: fffffbfff2854b11 R12: 0000000000000246
R13: ffff888026e41e00 R14: 00000000ffffffff R15: ffffffff8e937a60
 lock_is_held include/linux/lockdep.h:249 [inline]
 rcu_read_lock_sched_held+0x8d/0x130 kernel/rcu/update.c:126
 task_css include/linux/cgroup.h:434 [inline]
 mem_cgroup_from_task+0x4d/0x120 mm/memcontrol.c:892
 get_mem_cgroup_from_mm+0xd7/0x2a0 mm/memcontrol.c:945
 __mem_cgroup_charge+0x16/0x80 mm/memcontrol.c:4511
 mem_cgroup_charge include/linux/memcontrol.h:646 [inline]
 mfill_atomic_pte_copy mm/userfaultfd.c:302 [inline]
 mfill_atomic_pte mm/userfaultfd.c:685 [inline]
 mfill_atomic mm/userfaultfd.c:815 [inline]
 mfill_atomic_copy+0x90d/0x1a60 mm/userfaultfd.c:868
 userfaultfd_copy fs/userfaultfd.c:1612 [inline]
 userfaultfd_ioctl+0x2906/0x66f0 fs/userfaultfd.c:2016
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f763f185d29
RSP: 002b:00007f7640052038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f763f375fa0 RCX: 00007f763f185d29
RDX: 0000000020000080 RSI: 00000000c028aa03 RDI: 0000000000000006
RBP: 00007f763f201b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f763f375fa0 R15: 00007f763f49fa28
 </TASK>
rcu: rcu_preempt kthread starved for 9158 jiffies! g9889 f0x0 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:26264 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1850/0x4c30 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.13.0-rc6-syzkaller-00231-g77a903cd8e5a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:lock_is_held_type+0x13b/0x190
Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90000156db8 EFLAGS: 00000206
RAX: bd9518ea960b6000 RBX: 0000000000000001 RCX: 0000000080000100
RDX: ffff88801cacda00 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5fb0a0
RBP: 0000000000000000 R08: ffffffff8a6ec9ec R09: ffffc900001570b0
R10: ffffc900001570a0 R11: fffff5200002ade2 R12: 0000000000000246
R13: ffff88801cacda00 R14: 00000000ffffffff R15: ffffffff8e937ae0
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f398ce9ecdc CR3: 00000000307e4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 __find_rr_leaf+0x395/0x8e0 net/ipv6/route.c:800
 find_rr_leaf net/ipv6/route.c:856 [inline]
 rt6_select net/ipv6/route.c:900 [inline]
 fib6_table_lookup+0x413/0xbb0 net/ipv6/route.c:2195
 ip6_pol_route+0x273/0x15d0 net/ipv6/route.c:2231
 pol_lookup_func include/net/ip6_fib.h:616 [inline]
 fib6_rule_lookup+0x58c/0x790 net/ipv6/fib6_rules.c:117
 ip6_route_input_lookup net/ipv6/route.c:2300 [inline]
 ip6_route_input+0x859/0xd90 net/ipv6/route.c:2596
 ip6_rcv_finish+0x144/0x180 net/ipv6/ip6_input.c:77
 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5704 [inline]
 __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5817
 process_backlog+0x662/0x15b0 net/core/dev.c:6149
 __napi_poll+0xcb/0x490 net/core/dev.c:6902
 napi_poll net/core/dev.c:6971 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7093
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
net_ratelimit: 26606 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/11 08:29 upstream 77a903cd8e5a 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in userfaultfd_ioctl
* Struck through repros no longer work on HEAD.