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INFO: rcu detected stall in send_dm_alert (2)

Status: auto-obsoleted due to no activity on 2026/05/14 15:54
Subsystems: mm
Labels: prio:high
[Documentation on labels]
First crash: 255d, last: 127d
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
a5d1fb7c-a72a-4f46-8e0e-7fd8e0d60a88 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ✅ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: rcu detected stall in send_dm_alert (2) 2026/05/14 01:53 2026/05/14 01:53 2026/05/14 02:32 71153e5d9da49247dc7f1194a9cc04fb90c64f9c

			
		
e346aee7-7ebe-4fcd-924e-924f2ecc62e2 repro INFO: rcu detected stall in send_dm_alert (2) 2026/03/06 04:39 2026/03/06 04:39 2026/03/06 04:56 31e9c887f7dc24e04b3ca70d0d54fc34141844b0

			
		
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in send_dm_alert mm 1 3 372d 429d 0/29 auto-obsoleted due to no activity on 2025/09/11 14:25

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): P24/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=103017, q=1317 ncpus=2)
task:kworker/1:0     state:R  running task     stack:21384 pid:24    tgid:24    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events send_dm_alert
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: e6 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 54 e9 0e 0f 82 74 02 00 00 8b 35 9a 84 e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 e6 08 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc900001e7870 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4760 RCX: 0000000008bbdb57
RDX: 0000000000000000 RSI: ffffffff8da06f71 RDI: ffffffff8bf07440
RBP: 0000000000000002 R08: fd58e87402e40d98 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 page_ext_get+0x36/0x1a0 mm/page_ext.c:527
 __reset_page_owner+0x2b/0x1a0 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901
 discard_slab mm/slub.c:3330 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3876
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:408
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5650 [inline]
 __kmalloc_node_track_caller_noprof+0x345/0x8a0 mm/slub.c:5759
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601
 __alloc_skb+0x166/0x380 net/core/skbuff.c:670
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 genlmsg_new include/net/genetlink.h:611 [inline]
 reset_per_cpu_data+0x26/0x240 net/core/drop_monitor.c:146
 send_dm_alert+0x1e/0xf0 net/core/drop_monitor.c:197
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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)
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 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)
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)

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/30 19:49 upstream e69c7c175115 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in send_dm_alert
2025/10/08 20:04 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in send_dm_alert
2026/02/13 15:44 linux-next af98e93c5c39 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in send_dm_alert
* Struck through repros no longer work on HEAD.