INFO: rcu detected stall in asm_exc_page_fault

Status: upstream: reported on 2026/07/19 00:59
Reported-by: syzbot+2e5e664c4a8921206a3e@syzkaller.appspotmail.com
First crash: 83d, last: 48d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in asm_exc_page_fault (2) kasan mm 1 1 351d 351d 0/29 auto-obsoleted due to no activity on 2026/01/22 14:37
linux-5.15 INFO: rcu detected stall in asm_exc_page_fault 1 1 262d 262d 0/3 auto-obsoleted due to no activity on 2026/05/01 14:57
linux-6.1 INFO: rcu detected stall in asm_exc_page_fault 1 syz, C 2 33d 34d 0/3 upstream: reported C repro on 2026/09/05 19:18
upstream INFO: rcu detected stall in asm_exc_page_fault mm 1 syz error error 4 555d 945d 0/29 auto-obsoleted due to no activity on 2025/07/30 11:21
android-5-15 BUG: soft lockup in asm_exc_page_fault 1 syz, C error 3 768d 916d 0/2 auto-obsoleted due to no activity on 2024/12/10 17:09

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10453 ticks this GP) idle=e454/1/0x4000000000000000 softirq=237426/237428 fqs=1058
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   244180          4            0
rcu: 	cputime:     2776       6089            5   ==> 8880(ms)
rcu: 	(t=10502 jiffies g=338425 q=2561 ncpus=2)
CPU: 0 PID: 22765 Comm: syz.1.13258 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:sk_fullsock include/net/sock.h:2920 [inline]
RIP: 0010:sk_validate_xmit_skb include/net/sock.h:2965 [inline]
RIP: 0010:validate_xmit_skb+0x1aa/0xf30 net/core/dev.c:3729
Code: 80 3c 20 00 74 08 48 89 df e8 42 ed 5c f9 48 8b 1b 48 85 db 0f 84 b3 00 00 00 4c 8d 7b 12 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 25 0b 00 00 45 0f b6 3f bf 20 00 00 00 44 89 fe e8 ad
RSP: 0018:ffffc90000007320 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffff88804e9a4fc0 RCX: ffff88801b3bda00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000073f0 R08: ffff88801b3bda00 R09: 0000000000000002
R10: 0000000000004888 R11: 0000000000000100 R12: dffffc0000000000
R13: 1ffff110068ca103 R14: ffff888034650780 R15: ffff88804e9a4fd2
FS:  00007fbb623066c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000029c0 CR3: 0000000046f54000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 validate_xmit_skb_list+0x84/0x120 net/core/dev.c:3786
 sch_direct_xmit+0xe1/0x4a0 net/sched/sch_generic.c:330
 __dev_xmit_skb net/core/dev.c:3886 [inline]
 __dev_queue_xmit+0x162a/0x3630 net/core/dev.c:4429
 neigh_output include/net/neighbour.h:547 [inline]
 ip6_finish_output2+0xe2e/0x1620 net/ipv6/ip6_output.c:141
 dst_output include/net/dst.h:467 [inline]
 NF_HOOK include/linux/netfilter.h:304 [inline]
 ndisc_send_skb+0xbb9/0x1480 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x36b/0x640 net/ipv6/addrconf.c:4036
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x570/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7011
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 d1 3b c5 f6 e8 ec 36 f6 f6 fb bf 01 00 00 00 <e8> 31 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9000bb97500 EFLAGS: 00000286
RAX: bc75d458790cb100 RBX: 0000000000000000 RCX: bc75d458790cb100
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001
RBP: ffffc9000bb975a0 R08: ffffffff911ee537 R09: 1ffffffff223dca6
R10: dffffc0000000000 R11: fffffbfff223dca7 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92001772ea0
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:try_charge_memcg+0x428/0x17c0 mm/memcontrol.c:2684
Code: 00 00 f7 84 24 70 01 00 00 00 02 00 00 42 c6 44 28 12 f8 44 8b 74 24 24 0f 85 d3 0a 00 00 f7 c3 00 02 00 00 74 01 fb 45 84 e4 <4c> 8b 64 24 28 0f 85 67 10 00 00 e9 18 0d 00 00 44 89 f3 49 8d bc
RSP: 0018:ffffc9000bb97660 EFLAGS: 00000202
RAX: 1ffff92001772ee8 RBX: 0000000000000283 RCX: bc75d458790cb100
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1d32a0
RBP: ffffc9000bb97890 R08: ffffffff911ee537 R09: 1ffffffff223dca6
R10: dffffc0000000000 R11: fffffbfff223dca7 R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000000000040 R15: ffff8880b8e37e10
 try_charge mm/memcontrol.c:2865 [inline]
 charge_memcg+0x11b/0x3b0 mm/memcontrol.c:7090
 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:7111
 mem_cgroup_charge include/linux/memcontrol.h:686 [inline]
 wp_page_copy mm/memory.c:3118 [inline]
 do_wp_page+0x1378/0x34d0 mm/memory.c:3469
 handle_pte_fault mm/memory.c:5063 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x1306/0x4a50 mm/memory.c:5353
 do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
 handle_page_fault arch/x86/mm/fault.c:1463 [inline]
 exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:__put_user_4+0x11/0x20 arch/x86/lib/putuser.S:89
Code: 01 ca c3 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb
RSP: 0018:ffffc9000bb97e80 EFLAGS: 00050206
RAX: 000000000000000e RBX: 0000000000000000 RCX: 00002000000029c0
RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1d32a0
RBP: 000000000000000e R08: ffffffff8e8c7e2f R09: 1ffffffff1d18fc5
R10: dffffc0000000000 R11: fffffbfff1d18fc6 R12: 0000000000000000
R13: 00002000000029c0 R14: 0000000000000001 R15: 0000000000000005
 __sys_socketpair+0xb8/0x550 net/socket.c:1765
 __do_sys_socketpair net/socket.c:1831 [inline]
 __se_sys_socketpair net/socket.c:1828 [inline]
 __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1828
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbb6139e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbb62306028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007fbb61625fa0 RCX: 00007fbb6139e0d9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001
RBP: 00007fbb61435024 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000029c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbb61626038 R14: 00007fbb61625fa0 R15: 00007fff2d39ae78
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/23 05:24 linux-6.6.y c610b395b0a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in asm_exc_page_fault
2026/07/19 00:58 linux-6.6.y da47cbc25466 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in asm_exc_page_fault
* Struck through repros no longer work on HEAD.