rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11169/1:b..l P11179/3:b..l
rcu: (detected by 1, t=10502 jiffies, g=40569, q=1118 ncpus=2)
task:syz.3.1477 state:R running task stack:26912 pid:11179 tgid:11169 ppid:5838 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kasan_check_read+0xa/0x20 mm/kasan/shadow.c:31
Code: 31 ed eb cf cc cc cc cc cc 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 89 f6 48 8b 0c 24 <31> d2 e9 ef e4 ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90003bbef60 EFLAGS: 00000282
RAX: 0000000000000000 RBX: ffffc90003bbf0c0 RCX: ffffffff8a07ec37
RDX: ffffc90010a3a000 RSI: 0000000000000008 RDI: ffffc90003bbf0d0
RBP: 0000000000000005 R08: ffff8880280e8000 R09: 0000000000000002
R10: 0000000000000009 R11: 0000000000000002 R12: ffff888078050000
R13: dffffc0000000000 R14: 0000000000000005 R15: ffffc90003bbf068
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
ipv6_get_saddr_eval+0x207/0xee0 net/ipv6/addrconf.c:1601
__ipv6_dev_get_saddr+0x19d/0x440 net/ipv6/addrconf.c:1759
ipv6_dev_get_saddr+0x363/0xb70 net/ipv6/addrconf.c:1896
ip6_route_get_saddr include/net/ip6_route.h:147 [inline]
ip6_dst_lookup_tail+0xf2c/0x1510 net/ipv6/ip6_output.c:1146
ip6_dst_lookup_flow+0x47/0xe0 net/ipv6/ip6_output.c:1272
sctp_v6_get_dst+0x6c7/0x1c90 net/sctp/ipv6.c:327
sctp_transport_route+0x118/0x2f0 net/sctp/transport.c:448
sctp_assoc_add_peer+0x650/0x13b0 net/sctp/associola.c:663
sctp_connect_new_asoc+0x30a/0x690 net/sctp/socket.c:1100
sctp_sendmsg_new_asoc net/sctp/socket.c:1692 [inline]
sctp_sendmsg+0x155c/0x2840 net/sctp/socket.c:2003
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x19c/0x270 net/socket.c:742
____sys_sendmsg+0x52d/0x820 net/socket.c:2592
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
__sys_sendmmsg+0x227/0x430 net/socket.c:2735
__do_sys_sendmmsg net/socket.c:2762 [inline]
__se_sys_sendmmsg net/socket.c:2759 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f936ef8f749
RSP: 002b:00007f936fe4b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f936f1e6180 RCX: 00007f936ef8f749
RDX: 0000000000000001 RSI: 0000200000000980 RDI: 000000000000000c
RBP: 00007f936f013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f936f1e6218 R14: 00007f936f1e6180 R15: 00007fff06642538
task:syz.3.1477 state:R running task stack:24664 pid:11169 tgid:11169 ppid:5838 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
insert_page+0x189/0x2c0 mm/memory.c:2328
kcov_mmap+0xc7/0x130 kernel/kcov.c:506
vfs_mmap include/linux/fs.h:2053 [inline]
mmap_file mm/internal.h:167 [inline]
__mmap_new_file_vma mm/vma.c:2421 [inline]
__mmap_new_vma mm/vma.c:2484 [inline]
__mmap_region mm/vma.c:2708 [inline]
mmap_region+0x14b1/0x1d10 mm/vma.c:2786
do_mmap+0xc45/0x10d0 mm/mmap.c:558
vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581
ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f936ef8f783
RSP: 002b:00007fff066425f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f936f1e6308 RCX: 00007f936ef8f783
RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f936cdf6000
RBP: 00007f936f1e6270 R08: 00000000000000db R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f936f1e6270 R14: 00000000000016c1 R15: 0000000000000003
rcu: rcu_preempt kthread starved for 10586 jiffies! g40569 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:27776 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
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:variable_ffs arch/x86/include/asm/bitops.h:312 [inline]
RIP: 0010:handle_softirqs+0x161/0x7c0 kernel/softirq.c:610
Code: 89 6c 24 20 0f b7 db 48 c7 c7 60 d8 69 8b e8 06 aa d4 09 65 66 c7 05 74 dd fa 10 00 00 e8 77 8e 43 00 fb 48 c7 c5 c0 c0 c0 8d ff ff ff ff 0f bc c3 41 89 c6 41 ff c6 0f 84 85 03 00 00 89 5c
RSP: 0018:ffffc90000a08f40 EFLAGS: 00000206
RAX: 000000000161e688 RBX: 0000000000000100 RCX: 0000000080000101
RDX: 0000000000000000 RSI: ffffffff8d7928e5 RDI: ffffffff8bc083e0
RBP: ffffffff8dc0c0c0 R08: ffffffff8f822477 R09: 1ffffffff1f0448e
R10: dffffc0000000000 R11: fffffbfff1f0448f R12: 0000000000000000
R13: 0000000000000000 R14: ffff88801c6adb80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9a957f0d98 CR3: 000000003337f000 CR4: 0000000000350ef0
Call Trace:
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x60/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 1e 84 b6 f5 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 53 91 0e 00 f3 0f 1e fa fb f4 f3 83 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c6
RAX: 000000000161e685 RBX: ffffffff819713ee RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d7928e5 RDI: ffffffff8bc083e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822470
R13: 1ffff110038d5b70 R14: 0000000000000001 R15: 0000000000000001
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+0x1be/0x4d0 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