syzbot


INFO: rcu detected stall in mremap (4)

Status: auto-obsoleted due to no activity on 2026/04/23 05:52
Subsystems: mm
[Documentation on labels]
First crash: 91d, last: 91d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
2df3541d-966b-471e-9f0b-f9fe1b7d3d28 repro 💥 INFO: rcu detected stall in mremap (4) 2026/03/10 01:52 2026/03/10 01:52 2026/03/10 02:15 6972f30219093b03bcc1a54487e12a7097245c01 Error 429, Message: You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To monitor your current usage, head to: https://ai.dev/rate-limit. , Status: RESOURCE_EXHAUSTED, Details: [map[@type:type.googleapis.com/google.rpc.Help links:[map[description:Learn more about Gemini API quotas url:https://ai.google.dev/gemini-api/docs/rate-limits]]] map[@type:type.googleapis.com/google.rpc.DebugInfo detail:[ORIGINAL ERROR] generic::resource_exhausted: You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To monitor your current usage, head to: https://ai.dev/rate-limit. [google.rpc.error_details_ext] { message: "You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To monitor your current usage, head to: https://ai.dev/rate-limit. " details { type_url: "type.googleapis.com/language_labs.genai.debug.GeminiApiDebugInfo" value: "R\212\001\n\207\001\nTgenerativelanguage.googleapis.com/generate_content_paid_tier_1_input_tokens_internal\022\022\n\010location\022\006global\022\027\n\005model\022\016gemini-3.1-pro\030\300\204=" } details { [type.googleapis.com/google.rpc.Help] { links { description: "Learn more about Gemini API quotas" url: "https://ai.google.dev/gemini-api/docs/rate-limits" } } } }]]
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in mremap 1 1 159d 159d 0/3 auto-obsoleted due to no activity on 2026/02/24 13:38
upstream INFO: rcu detected stall in mremap kasan mm 1 1 1555d 1555d 0/29 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in mremap (3) kernel 1 1 230d 230d 0/29 auto-obsoleted due to no activity on 2025/11/05 16:37
upstream INFO: rcu detected stall in mremap (2) kasan mm 1 1 397d 397d 0/29 auto-obsoleted due to no activity on 2025/06/21 10:47
linux-6.1 INFO: rcu detected stall in mremap 1 1 110d 110d 0/3 auto-obsoleted due to no activity on 2026/04/14 04:10
upstream INFO: rcu detected stall in sys_mremap mm 1 1 494d 494d 0/29 auto-obsoleted due to no activity on 2025/03/16 11:40

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)
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): P20104/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=469461, q=615 ncpus=2)
task:syz.7.11620     state:R  running task     stack:24792 pid:20104 tgid:20098 ppid:15837  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0x14ef/0x4fb0 kernel/sched/core.c:6867
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194
 irqentry_exit+0x597/0x620 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d7/0x3a0 kernel/locking/lockdep.c:5893
Code: 61 30 11 00 00 00 00 eb b5 e8 95 3a d9 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 85 1b 30 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d c2 b7 32
RSP: 0000:ffffc900046ef080 EFLAGS: 00000282
RAX: 97abc6b7712da200 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000002 RSI: ffffffff8dd38b9b RDI: ffffffff8be73880
RBP: ffff888029ba2a00 R08: ffff88801c5bcec7 R09: 1ffff110038b79d8
R10: dffffc0000000000 R11: ffffed10038b79d9 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8e35a360 R15: ffff888029ba1e80
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 __update_page_owner_free_handle+0x451/0x470 mm/page_owner.c:295
 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:321
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xbb0/0xd10 mm/page_alloc.c:2973
 discard_slab mm/slub.c:3346 [inline]
 __put_partials+0x146/0x170 mm/slub.c:3886
 __slab_free+0x294/0x320 mm/slub.c:5956
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x370/0x6e0 mm/slub.c:5270
 mt_alloc_one lib/maple_tree.c:174 [inline]
 mas_alloc_nodes+0x291/0x350 lib/maple_tree.c:1110
 mas_preallocate+0x2d6/0x640 lib/maple_tree.c:5194
 vma_iter_prealloc mm/vma.h:505 [inline]
 __split_vma+0x309/0xa50 mm/vma.c:526
 vms_gather_munmap_vmas+0x2f1/0x1320 mm/vma.c:1402
 do_vmi_align_munmap+0x2b4/0x4b0 mm/vma.c:1570
 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1627
 shrink_vma mm/mremap.c:1341 [inline]
 mremap_to+0x270/0x850 mm/mremap.c:1395
 do_mremap mm/mremap.c:1941 [inline]
 __do_sys_mremap mm/mremap.c:1997 [inline]
 __se_sys_mremap+0xd37/0xfc0 mm/mremap.c:1965
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd5ad9acb9
RSP: 002b:00007efd5bcc1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000019
RAX: ffffffffffffffda RBX: 00007efd5b016180 RCX: 00007efd5ad9acb9
RDX: 0000000000003000 RSI: 0000000000800000 RDI: 00002000007fe000
RBP: 00007efd5ae08bf7 R08: 000020000022c000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efd5b016218 R14: 00007efd5b016180 R15: 00007efd5b13fa48
 </TASK>
rcu: rcu_preempt kthread starved for 786 jiffies! g469461 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:27072 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0x14ef/0x4fb0 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:6964
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 15975 Comm: kworker/u8:16 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:222 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:233 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:649 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1231 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x50/0x330 kernel/locking/lockdep.c:5831
Code: ac 24 98 00 00 00 65 48 8b 05 dc 4e 30 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 df 4e 30 11 83 f8 08 0f 83 83 01 00 00 89 c0 <48> 0f a3 05 08 a4 2f 0e 73 0d e8 51 25 09 00 84 c0 0f 84 ca 01 00
RSP: 0018:ffffc90000006b78 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e35a360
RBP: ffffffff8174c0e5 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000006d38 R11: ffffffff81ae5cf0 R12: 0000000000000002
R13: ffffffff8e35a360 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125928000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb8bef3eccc CR3: 000000007dc62000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x370/0x6e0 mm/slub.c:5270
 skb_ext_maybe_cow net/core/skbuff.c:7043 [inline]
 skb_ext_add+0x1b6/0x8f0 net/core/skbuff.c:7118
 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:169 [inline]
 br_nf_forward_ip+0xc6/0x7e0 net/bridge/br_netfilter_hooks.c:681
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
 __br_forward+0x397/0x540 net/bridge/br_forward.c:115
 br_handle_frame_finish+0x1492/0x1b40 net/bridge/br_input.c:229
 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0x989/0x1520 net/bridge/br_input.c:442
 __netif_receive_skb_core+0x98f/0x30a0 net/core/dev.c:6039
 __netif_receive_skb_one_core net/core/dev.c:6150 [inline]
 __netif_receive_skb+0x72/0x370 net/core/dev.c:6265
 process_backlog+0x54e/0x1340 net/core/dev.c:6617
 __napi_poll+0xae/0x320 net/core/dev.c:7681
 napi_poll net/core/dev.c:7744 [inline]
 net_rx_action+0x696/0xe30 net/core/dev.c:7896
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 cfg80211_inform_single_bss_data+0x13b9/0x1ab0 net/wireless/scan.c:2389
 cfg80211_inform_bss_data+0x233/0x3bb0 net/wireless/scan.c:3228
 cfg80211_inform_bss_frame_data+0x3c7/0x710 net/wireless/scan.c:3319
 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230
 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1901/0x2c80 net/mac80211/ibss.c:1602
 ieee80211_iface_process_skb net/mac80211/iface.c:1736 [inline]
 ieee80211_iface_work+0x85e/0x12b0 net/mac80211/iface.c:1790
 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
net_ratelimit: 9209 callbacks suppressed
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:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:a0:0c:62:28:86, 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)
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 veth0_to_bridge with own address as source address (addr:aa:a0:0c:62:28:86, 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)
net_ratelimit: 15427 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:a0:0c:62:28:86, 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)
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 veth0_to_bridge with own address as source address (addr:aa:a0:0c:62:28:86, 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)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/23 05:43 upstream a66191c590b3 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in mremap
* Struck through repros no longer work on HEAD.