[syzbot] [sctp?] INFO: rcu detected stall in inet6_rtm_newaddr (3)
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syzbot
May 14, 2025, 3:22:33 AMMay 14
to da...@davemloft.net, dsa...@kernel.org, edum...@google.com, ho...@kernel.org, ku...@kernel.org, linux-...@vger.kernel.org, linux...@vger.kernel.org, lucie...@gmail.com, marcelo...@gmail.com, net...@vger.kernel.org, pab...@redhat.com, syzkall...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: e9565e23cd89 Merge tag 'sched_ext-for-6.15-rc6-fixes' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17bd4af4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=bc44e21a0b824ef8
dashboard link: https://syzkaller.appspot.com/bug?extid=3e17d9c9a137bb913b61
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a572f4580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/35d8c0778a31/disk-e9565e23.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5f73f5f4ca4c/vmlinux-e9565e23.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ad13ba9fecea/bzImage-e9565e23.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3e17d9...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 ticks this GP) idle=4c1c/1/0x4000000000000000 softirq=17820/17820 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=13441, q=130 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5964 Comm: syz-executor Not tainted 6.15.0-rc6-syzkaller-00047-ge9565e23cd89 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_release+0x2a2/0x3e0 kernel/locking/lockdep.c:5890
Code: b8 09 b8 ff ff ff ff 65 0f c1 05 49 79 d7 10 83 f8 01 75 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 <75> 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 fb 3c d7 10 48 3b 44
RSP: 0018:ffffc90000007bf8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000006 RCX: 51a5468642bc5400
RDX: 0000000000000002 RSI: ffffffff8d936f16 RDI: ffffffff8bc1d820
RBP: ffff8880269f8b40 R08: ffff88802cf3bc83 R09: 1ffff110059e7790
R10: dffffc0000000000 R11: ffffed10059e7791 R12: 0000000000000002
R13: 0000000000000002 R14: ffff88805a967300 R15: ffff8880269f8000
FS: 0000555587b64500(0000) GS:ffff8881260c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 000000007d574000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
advance_sched+0x99f/0xc90 net/sched/sch_taprio.c:981
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x180c/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b 7c 24 48 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 <74> 05 e8 7d 05 b0 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03
RSP: 0018:ffffc90003fceeb8 EFLAGS: 00000246
RAX: 1ffff920007f9df8 RBX: ffffffff90b37101 RCX: 0000000000000001
RDX: ffffc90003fcefc8 RSI: dffffc0000000000 RDI: ffffc90003fcefc0
RBP: dffffc0000000000 R08: ffffc90003fcff48 R09: 0000000000000000
R10: ffffc90003fcefd8 R11: fffff520007f9dfd R12: ffffc90003fcff48
R13: ffffc90003fcefd8 R14: ffffc90003fcef88 R15: ffffffff8171ca05
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4327 [inline]
__kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339
kmalloc_noprof include/linux/slab.h:909 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
ip6_route_info_create+0x4b3/0x1360 net/ipv6/route.c:3802
ip6_route_add+0x28/0x160 net/ipv6/route.c:3896
addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
inet6_addr_add+0x6b2/0xc00 net/ipv6/addrconf.c:3052
inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5063
rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x21c/0x490 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:727
__sys_sendto+0x3bd/0x520 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f281bd907fc
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007f281c0df670 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f281cae4620 RCX: 00007f281bd907fc
RDX: 0000000000000040 RSI: 00007f281cae4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007f281c0df6c4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f281cae4670 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=8937
rcu: rcu_preempt kthread starved for 10502 jiffies! g13441 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: e9565e23cd89 Merge tag 'sched_ext-for-6.15-rc6-fixes' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17bd4af4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=bc44e21a0b824ef8
dashboard link: https://syzkaller.appspot.com/bug?extid=3e17d9c9a137bb913b61
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a572f4580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/35d8c0778a31/disk-e9565e23.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5f73f5f4ca4c/vmlinux-e9565e23.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ad13ba9fecea/bzImage-e9565e23.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3e17d9...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 ticks this GP) idle=4c1c/1/0x4000000000000000 softirq=17820/17820 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=13441, q=130 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5964 Comm: syz-executor Not tainted 6.15.0-rc6-syzkaller-00047-ge9565e23cd89 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_release+0x2a2/0x3e0 kernel/locking/lockdep.c:5890
Code: b8 09 b8 ff ff ff ff 65 0f c1 05 49 79 d7 10 83 f8 01 75 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 <75> 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 fb 3c d7 10 48 3b 44
RSP: 0018:ffffc90000007bf8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000006 RCX: 51a5468642bc5400
RDX: 0000000000000002 RSI: ffffffff8d936f16 RDI: ffffffff8bc1d820
RBP: ffff8880269f8b40 R08: ffff88802cf3bc83 R09: 1ffff110059e7790
R10: dffffc0000000000 R11: ffffed10059e7791 R12: 0000000000000002
R13: 0000000000000002 R14: ffff88805a967300 R15: ffff8880269f8000
FS: 0000555587b64500(0000) GS:ffff8881260c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 000000007d574000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
advance_sched+0x99f/0xc90 net/sched/sch_taprio.c:981
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x180c/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b 7c 24 48 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 <74> 05 e8 7d 05 b0 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03
RSP: 0018:ffffc90003fceeb8 EFLAGS: 00000246
RAX: 1ffff920007f9df8 RBX: ffffffff90b37101 RCX: 0000000000000001
RDX: ffffc90003fcefc8 RSI: dffffc0000000000 RDI: ffffc90003fcefc0
RBP: dffffc0000000000 R08: ffffc90003fcff48 R09: 0000000000000000
R10: ffffc90003fcefd8 R11: fffff520007f9dfd R12: ffffc90003fcff48
R13: ffffc90003fcefd8 R14: ffffc90003fcef88 R15: ffffffff8171ca05
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4327 [inline]
__kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339
kmalloc_noprof include/linux/slab.h:909 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
ip6_route_info_create+0x4b3/0x1360 net/ipv6/route.c:3802
ip6_route_add+0x28/0x160 net/ipv6/route.c:3896
addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
inet6_addr_add+0x6b2/0xc00 net/ipv6/addrconf.c:3052
inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5063
rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x21c/0x490 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:727
__sys_sendto+0x3bd/0x520 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f281bd907fc
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007f281c0df670 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f281cae4620 RCX: 00007f281bd907fc
RDX: 0000000000000040 RSI: 00007f281cae4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007f281c0df6c4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f281cae4670 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=8937
rcu: rcu_preempt kthread starved for 10502 jiffies! g13441 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
8:49 AM (6 hours ago) 8:49 AM
to da...@davemloft.net, dsa...@kernel.org, edum...@google.com, ho...@kernel.org, ku...@kernel.org, linux-...@vger.kernel.org, linux...@vger.kernel.org, lucie...@gmail.com, marcelo...@gmail.com, net...@vger.kernel.org, pab...@redhat.com, syzkall...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 12b95d29eb97 Add linux-next specific files for 20251217
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10c69d92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2b21d95ed921dffe
dashboard link: https://syzkaller.appspot.com/bug?extid=3e17d9c9a137bb913b61
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10974a2a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1003177c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9fb4b501730c/disk-12b95d29.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fc92d98fa8d2/vmlinux-12b95d29.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f25cfc55950a/bzImage-12b95d29.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3e17d9...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6135/1:b..l P5964/2:b..l
rcu: (detected by 1, t=10502 jiffies, g=14189, q=315 ncpus=2)
task:syz-executor state:R running task stack:19496 pid:5964 tgid:5964 ppid:5963 task_flags:0x400140 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline]
RIP: 0010:unwind_next_frame+0x214/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: ef 08 8b 15 6e 32 47 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 f8 f5 e0 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 2c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0018:ffffc900043eed38 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: 0000000000000001 RCX: a87a6bbecf920600
RDX: 00000000000a60ce RSI: ffffffff8be075c0 RDI: ffffffff8be07580
RBP: dffffc0000000000 R08: ffffffff81742f85 R09: ffffffff8e13f8a0
R10: ffffc900043eee58 R11: ffffffff81ad9f20 R12: ffffffff8aa4f9ce
R13: ffffffff910789dc R14: ffffc900043eee08 R15: 000000000009a4f9
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
sctp_inet6addr_event+0x37f/0x740 net/sctp/ipv6.c:86
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223
ipv6_add_addr+0xda9/0x1090 net/ipv6/addrconf.c:1186
inet6_addr_add+0x3c3/0xce0 net/ipv6/addrconf.c:3050
inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5059
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
__sock_sendmsg net/socket.c:752 [inline]
__sys_sendto+0x3ce/0x540 net/socket.c:2221
__do_sys_sendto net/socket.c:2228 [inline]
__se_sys_sendto net/socket.c:2224 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2224
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f30ce1915dc
RSP: 002b:00007ffc905dd720 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f30cef14620 RCX: 00007f30ce1915dc
RDX: 0000000000000040 RSI: 00007f30cef14670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc905dd774 R09: 000000000000000c
</TASK>
task:sed state:R running task stack:24312 pid:6135 tgid:6135 ppid:6134 task_flags:0x400000 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:arch_atomic64_read arch/x86/include/asm/atomic64_64.h:-1 [inline]
RIP: 0010:raw_atomic64_read include/linux/atomic/atomic-arch-fallback.h:2583 [inline]
RIP: 0010:atomic64_read include/linux/atomic/atomic-instrumented.h:1611 [inline]
RIP: 0010:ktime_get_coarse_real_ts64_mg+0x37/0x1e0 kernel/time/timekeeping.c:2445
Code: 53 48 83 ec 10 48 89 fb e8 36 04 12 00 48 c7 c7 c0 12 e1 8d be 08 00 00 00 e8 65 62 78 00 48 8b 05 5e 4d 31 0c 48 89 44 24 08 <4c> 8d 73 08 49 89 dd 49 c1 ed 03 4c 89 f0 48 c1 e8 03 48 89 04 24
RSP: 0018:ffffc900034d75b8 EFLAGS: 00000256
RAX: 000000261054af24 RBX: ffffc900034d7640 RCX: ffffffff81afc55b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de112c0
RBP: ffffc900034d76b8 R08: ffffffff8de112c7 R09: 1ffffffff1bc2258
R10: dffffc0000000000 R11: fffffbfff1bc2259 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc900034d7640 R15: dffffc0000000000
current_time+0x8e/0x360 fs/inode.c:2343
atime_needs_update+0x320/0x6d0 fs/inode.c:2206
pick_link+0x549/0xfa0 fs/namei.c:1983
step_into_slowpath+0x53b/0x7d0 fs/namei.c:2066
step_into fs/namei.c:2091 [inline]
walk_component fs/namei.c:2227 [inline]
link_path_walk+0xd50/0x18d0 fs/namei.c:2589
path_openat+0x2b0/0x3840 fs/namei.c:4782
do_filp_open+0x1fa/0x410 fs/namei.c:4813
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fabfcd360ba
RSP: 002b:00007fff94803a88 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fff94803b00 RCX: 00007fabfcd360ba
RDX: 0000000000080000 RSI: 00007fff94803b00 RDI: 00000000ffffff9c
RBP: 00007fff94803af0 R08: 00007fff94803cf7 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000017
R13: 00007fabfcd0a000 R14: 00007fff94803d10 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread starved for 10598 jiffies! g14189 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 4e 2b 00 f3 0f 1e fa fb f4 <e9> 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: fcd00228fb9d7700 RBX: ffffffff8197888a RCX: fcd00228fb9d7700
RDX: 0000000000000001 RSI: ffffffff8d99597b RDI: ffffffff8be075e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fa20e70
R13: 1ffff11003adcb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d2d000(0000) knlGS:0000000000000000
Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147
</TASK>
---
HEAD commit: 12b95d29eb97 Add linux-next specific files for 20251217
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10c69d92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2b21d95ed921dffe
dashboard link: https://syzkaller.appspot.com/bug?extid=3e17d9c9a137bb913b61
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10974a2a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1003177c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9fb4b501730c/disk-12b95d29.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fc92d98fa8d2/vmlinux-12b95d29.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f25cfc55950a/bzImage-12b95d29.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3e17d9...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14189, q=315 ncpus=2)
task:syz-executor state:R running task stack:19496 pid:5964 tgid:5964 ppid:5963 task_flags:0x400140 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline]
RIP: 0010:unwind_next_frame+0x214/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: ef 08 8b 15 6e 32 47 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 f8 f5 e0 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 2c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0018:ffffc900043eed38 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: 0000000000000001 RCX: a87a6bbecf920600
RDX: 00000000000a60ce RSI: ffffffff8be075c0 RDI: ffffffff8be07580
RBP: dffffc0000000000 R08: ffffffff81742f85 R09: ffffffff8e13f8a0
R10: ffffc900043eee58 R11: ffffffff81ad9f20 R12: ffffffff8aa4f9ce
R13: ffffffff910789dc R14: ffffc900043eee08 R15: 000000000009a4f9
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
sctp_inet6addr_event+0x37f/0x740 net/sctp/ipv6.c:86
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223
ipv6_add_addr+0xda9/0x1090 net/ipv6/addrconf.c:1186
inet6_addr_add+0x3c3/0xce0 net/ipv6/addrconf.c:3050
inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5059
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
__sock_sendmsg net/socket.c:752 [inline]
__sys_sendto+0x3ce/0x540 net/socket.c:2221
__do_sys_sendto net/socket.c:2228 [inline]
__se_sys_sendto net/socket.c:2224 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2224
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f30ce1915dc
RSP: 002b:00007ffc905dd720 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f30cef14620 RCX: 00007f30ce1915dc
RDX: 0000000000000040 RSI: 00007f30cef14670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc905dd774 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f30cef14670 R15: 0000000000000000
</TASK>
task:sed state:R running task stack:24312 pid:6135 tgid:6135 ppid:6134 task_flags:0x400000 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:arch_atomic64_read arch/x86/include/asm/atomic64_64.h:-1 [inline]
RIP: 0010:raw_atomic64_read include/linux/atomic/atomic-arch-fallback.h:2583 [inline]
RIP: 0010:atomic64_read include/linux/atomic/atomic-instrumented.h:1611 [inline]
RIP: 0010:ktime_get_coarse_real_ts64_mg+0x37/0x1e0 kernel/time/timekeeping.c:2445
Code: 53 48 83 ec 10 48 89 fb e8 36 04 12 00 48 c7 c7 c0 12 e1 8d be 08 00 00 00 e8 65 62 78 00 48 8b 05 5e 4d 31 0c 48 89 44 24 08 <4c> 8d 73 08 49 89 dd 49 c1 ed 03 4c 89 f0 48 c1 e8 03 48 89 04 24
RSP: 0018:ffffc900034d75b8 EFLAGS: 00000256
RAX: 000000261054af24 RBX: ffffc900034d7640 RCX: ffffffff81afc55b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de112c0
RBP: ffffc900034d76b8 R08: ffffffff8de112c7 R09: 1ffffffff1bc2258
R10: dffffc0000000000 R11: fffffbfff1bc2259 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc900034d7640 R15: dffffc0000000000
current_time+0x8e/0x360 fs/inode.c:2343
atime_needs_update+0x320/0x6d0 fs/inode.c:2206
pick_link+0x549/0xfa0 fs/namei.c:1983
step_into_slowpath+0x53b/0x7d0 fs/namei.c:2066
step_into fs/namei.c:2091 [inline]
walk_component fs/namei.c:2227 [inline]
link_path_walk+0xd50/0x18d0 fs/namei.c:2589
path_openat+0x2b0/0x3840 fs/namei.c:4782
do_filp_open+0x1fa/0x410 fs/namei.c:4813
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fabfcd360ba
RSP: 002b:00007fff94803a88 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fff94803b00 RCX: 00007fabfcd360ba
RDX: 0000000000080000 RSI: 00007fff94803b00 RDI: 00000000ffffff9c
RBP: 00007fff94803af0 R08: 00007fff94803cf7 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000017
R13: 00007fabfcd0a000 R14: 00007fff94803d10 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread starved for 10598 jiffies! g14189 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
rcu: RCU grace-period kthread stack dump:
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 4e 2b 00 f3 0f 1e fa fb f4 <e9> 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: fcd00228fb9d7700 RBX: ffffffff8197888a RCX: fcd00228fb9d7700
RDX: 0000000000000001 RSI: ffffffff8d99597b RDI: ffffffff8be075e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fa20e70
R13: 1ffff11003adcb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d2d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fabfca09a10 CR3: 0000000076504000 CR4: 00000000003526f0
Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147
</TASK>
---
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