syzbot


INFO: rcu detected stall in brk (2)

Status: upstream: reported syz repro on 2024/10/31 16:03
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+7402e6c8042635c93ead@syzkaller.appspotmail.com
First crash: 151d, last: 85d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] [input?] [usb?] INFO: rcu detected stall in brk (2) 8 (10) 2024/11/01 12:14
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in brk mm 1 341d 341d 0/28 auto-obsoleted due to no activity on 2024/07/20 02:57
Last patch testing requests (5)
Created Duration User Patch Repo Result
2025/03/27 02:34 20m retest repro upstream report log
2025/01/20 18:54 14m retest repro https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing report log
2025/01/16 01:52 16m retest repro upstream report log
2024/11/11 17:27 1h04m retest repro https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing report log
2024/10/31 16:23 14m lorenzo.stoakes@oracle.com git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/ mm-hotfixes-unstable OK log

Sample crash report:
bridge0: received packet on bridge_slave_0 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): P6032/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=10893, q=236 ncpus=2)
task:syz-executor    state:R  running task     stack:25392 pid:6032  tgid:6032  ppid:5846   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7078
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:stack_trace_consume_entry+0x0/0x170 kernel/stacktrace.c:83
Code: 75 0a e8 33 21 14 00 e9 35 ff ff ff 49 c7 c4 ea ff ff ff eb c7 e8 00 05 95 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 48 89 fb 48 83 c7
RSP: 0018:ffffc900033c77c8 EFLAGS: 00000282
RAX: ffffffff81f14dc8 RBX: ffffc900033c77d0 RCX: 0000000000000000
RDX: 1ffff92000678f03 RSI: ffffffff81f14dc8 RDI: ffffc900033c7890
RBP: ffffc900033c7860 R08: ffffc900033c7804 R09: ffffffff90bbc40e
R10: ffffc900033c77d0 R11: 000000000000fb92 R12: ffffffff81852eb0
R13: ffffc900033c7890 R14: 0000000000000000 R15: ffff8880279d1e00
 arch_stack_walk+0x86/0x100 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
 save_stack+0x162/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x8d/0x400 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2659
 __put_partials+0x14c/0x170 mm/slub.c:3157
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_noprof+0x1c8/0x3b0 mm/slub.c:4175
 vma_lock_alloc kernel/fork.c:446 [inline]
 vm_area_alloc+0xe0/0x1c0 kernel/fork.c:477
 do_brk_flags+0x293/0x12b0 mm/mmap.c:1562
 __do_sys_brk+0x6b3/0xa50 mm/mmap.c:197
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe84979d186
RSP: 002b:00007ffdc122f540 EFLAGS: 00000246 ORIG_RAX: 000000000000000c
RAX: ffffffffffffffda RBX: 0000000000000e80 RCX: 00007fe84979d186
RDX: 00005555810f9000 RSI: 000000000000000c RDI: 00005555810f9e80
RBP: 00007fe849885ac0 R08: 0000000000000002 R09: 00007fe84982bfb4
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 00000000000001b0 R14: 0000000000000980 R15: 00007fe84994c700
 </TASK>
rcu: rcu_preempt kthread starved for 10490 jiffies! g10893 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27568 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 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: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc5-syzkaller-00006-g56e6a3499e14 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x70 kernel/kcov.c:217
Code: cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 74 8a 6a 7e <65> 8b 05 75 8a 6a 7e a9 00 01 ff 00 48 8b 34 24 74 1d f6 c4 01 74
RSP: 0018:ffffc900001e6aa8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffffffff88fd3a51
RDX: ffff88801d680000 RSI: 00000000000005ee RDI: 0000000000000004
RBP: ffff8881544c1b40 R08: 0000000000000004 R09: 00000000000005ee
R10: 0000000000000046 R11: 0000000000000b8f R12: 00000000000005ee
R13: 0000000000000001 R14: 00000000000005dc R15: ffff8881544c1b40
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe8497b46c0 CR3: 0000000031340000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 is_skb_forwardable+0x1b2/0x210 net/core/dev.c:2180
 br_dev_queue_push_xmit+0x9f/0x8a0 net/bridge/br_forward.c:36
 br_nf_dev_queue_xmit+0x6db/0x2a10 net/bridge/br_netfilter_hooks.c:951
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 br_nf_post_routing+0x8ee/0x11b0 net/bridge/br_netfilter_hooks.c:997
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626
 nf_hook+0x474/0x7d0 include/linux/netfilter.h:269
 NF_HOOK include/linux/netfilter.h:312 [inline]
 br_forward_finish+0xcd/0x130 net/bridge/br_forward.c:66
 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1198
 br_nf_forward_finish+0x66a/0xba0 net/bridge/br_netfilter_hooks.c:693
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 br_nf_forward_ip.part.0+0x610/0x820 net/bridge/br_netfilter_hooks.c:747
 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:707 [inline]
 br_nf_forward+0xf11/0x1bd0 net/bridge/br_netfilter_hooks.c:804
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626
 nf_hook+0x474/0x7d0 include/linux/netfilter.h:269
 NF_HOOK include/linux/netfilter.h:312 [inline]
 __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115
 deliver_clone+0x5b/0xa0 net/bridge/br_forward.c:131
 maybe_deliver+0xa7/0x120 net/bridge/br_forward.c:190
 br_flood+0x17e/0x5c0 net/bridge/br_forward.c:236
 br_handle_frame_finish+0xda5/0x1c80 net/bridge/br_input.c:215
 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1198
 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154
 NF_HOOK include/linux/netfilter.h:314 [inline]
 br_nf_pre_routing_ipv6+0x3ce/0x8c0 net/bridge/br_netfilter_ipv6.c:184
 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:536
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
 br_handle_frame+0x9eb/0x14a0 net/bridge/br_input.c:424
 __netif_receive_skb_core.constprop.0+0xa76/0x4470 net/core/dev.c:5566
 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5670
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5785
 process_backlog+0x443/0x15f0 net/core/dev.c:6117
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6883
 napi_poll net/core/dev.c:6952 [inline]
 net_rx_action+0xa94/0x1010 net/core/dev.c:7074
 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
 run_ksoftirqd kernel/softirq.c:950 [inline]
 run_ksoftirqd+0x3a/0x60 kernel/softirq.c:942
 smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 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: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 veth0_to_bridge 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 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 veth0_to_bridge 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 veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/02 01:50 upstream 56e6a3499e14 d3ccff63 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in brk
2024/10/27 16:00 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing c6d9e43954bf 65e8686b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in brk
* Struck through repros no longer work on HEAD.