INFO: rcu detected stall in uprobe_mmap

Status: auto-obsoleted due to no activity on 2026/10/01 13:54
Subsystems: perf trace
Labels: prio:low
[Documentation on labels]
First crash: 119d, last: 119d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
3318fd1b assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in uprobe_mmap 2026/07/05 00:00 2026/07/05 00:00 2026/07/05 01:02 93f57954

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P19526/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=113441, q=702 ncpus=2)
task:syz.9.3646      state:R  running task     stack:25208 pid:19526 tgid:19518 ppid:14051  task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x205/0xa00 kernel/entry/common.c:167
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5844 [inline]
RIP: 0010:lock_acquire+0x140/0x370 kernel/locking/lockdep.c:5825
Code: 0f 86 26 ff ff ff 90 0f 0b 90 e9 1d ff ff ff 48 8b 74 24 68 48 89 ef e8 ce bd 94 00 8b 0d ec f3 3c 0f 85 c9 0f 84 bd 00 00 00 <65> 8b 05 49 05 7e 12 85 c0 0f 85 ae 00 00 00 65 48 8b 05 81 be 7d
RSP: 0018:ffffc90004476a88 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81f31713 RDI: fffffbfff1d7cc18
RBP: ffffffff8ebe60c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fa56179d000 R11: 0000000000000001 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:840 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
 is_module_text_address+0x33/0x220 kernel/module/main.c:3921
 kernel_text_address kernel/extable.c:119 [inline]
 kernel_text_address+0x81/0x100 kernel/extable.c:94
 __kernel_text_address+0xd/0x30 kernel/extable.c:79
 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:385
 arch_stack_walk+0xa6/0xf0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5515
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 vlan_vid_info_alloc net/8021q/vlan_core.c:196 [inline]
 __vlan_vid_add net/8021q/vlan_core.c:302 [inline]
 vlan_vid_add+0x326/0x730 net/8021q/vlan_core.c:336
 __vlan_vid_add net/bridge/br_vlan.c:119 [inline]
 __vlan_add+0x27c7/0x2e40 net/bridge/br_vlan.c:289
 nbp_vlan_add+0x258/0x3e0 net/bridge/br_vlan.c:1348
 br_vlan_info+0x159/0x3d0 net/bridge/br_netlink.c:711
 br_process_vlan_info+0x404/0x8f0 net/bridge/br_netlink.c:774
 br_afspec+0x432/0x670 net/bridge/br_netlink.c:842
 br_setlink+0x36f/0x5d0 net/bridge/br_netlink.c:1159
 rtnl_bridge_setlink+0x56d/0x740 net/core/rtnetlink.c:5651
 rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:7085
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:775 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
 __sys_sendmsg+0x160/0x210 net/socket.c:2770
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa56179de59
RSP: 002b:00007fa55f9f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa561a26090 RCX: 00007fa56179de59
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000b
RBP: 00007fa561833e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa561a26128 R14: 00007fa561a26090 R15: 00007ffcfe066ca8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g113441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=91788
rcu: rcu_preempt kthread starved for 10502 jiffies! g113441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27432 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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: 19545 Comm: modprobe Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:246 [inline]
RIP: 0010:mark_lock+0x54/0xa20 kernel/locking/lockdep.c:4731
Code: 83 fa 08 74 6d 41 be 01 00 00 00 89 d9 41 d3 e6 4d 63 f6 41 0f b7 44 24 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 0e b0 84 14 73 5b <48> 8d 04 80 48 8d 04 80 48 8d 04 c5 e0 ed 69 96 4c 89 f1 48 23 48
RSP: 0018:ffffc90000007ca0 EFLAGS: 00000007
RAX: 00000000000000dd RBX: 0000000000000008 RCX: 0000000000000008
RDX: 0000000000000008 RSI: ffff888035cf5698 RDI: ffff888035cf4a80
RBP: ffffc90000007d38 R08: 0000000000000001 R09: 0000000000000002
R10: 0000000000000003 R11: 0000000000000003 R12: ffff888035cf5698
R13: ffff888035cf4a80 R14: 0000000000000100 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888123dee000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcfbe1a6ff8 CR3: 00000000835d1000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4674 [inline]
 __lock_acquire+0x49f/0x1a40 kernel/locking/lockdep.c:5191
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:174
 __run_hrtimer kernel/time/hrtimer.c:2036 [inline]
 __hrtimer_run_queues+0x1b7/0x9c0 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 bb bf 7d 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 06 c1 3c 0f 0f 82 ac 02 00 00 8b 35 ce f4 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d bf 7d 12 0f 85 ec 02 00 00 48 83 c4
RSP: 0018:ffffc900048c7408 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 5581578dcaf923e8
RDX: 0000000000000000 RSI: ffffffff8e17c6a8 RDI: ffffffff8c400b80
RBP: ffffffff8ed2b878 R08: 00000000bdfdfe7a R09: 0000000000000be5
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
 __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline]
 _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:232
 build_probe_list kernel/events/uprobes.c:1539 [inline]
 uprobe_mmap+0x2ad/0x1070 kernel/events/uprobes.c:1619
 __mmap_complete mm/vma.c:2628 [inline]
 __mmap_region+0xbef/0x2db0 mm/vma.c:2783
 mmap_region+0x35d/0x620 mm/vma.c:2860
 do_mmap+0xc63/0x12f0 mm/mmap.c:560
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb80d20d242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffedc2ab8f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fb80cf2b000 RCX: 00007fb80d20d242
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007fb80cf2b000
RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000004000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffedc2ab980
R13: 00007fb80d1e2050 R14: 00007ffedc2abd30 R15: 00000fffdb855722
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/03 13:49 upstream 87320be9f0d2 58bf2096 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in uprobe_mmap
* Struck through repros no longer work on HEAD.