rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5833/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=53341, q=244 ncpus=2)
task:syz-executor state:R running task stack:21736 pid:5833 tgid:5833 ppid:5829 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_is_watching+0x70/0xb0 kernel/rcu/tree.c:747
Code: c3 58 cf 9d 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 99 8f f5 10 74 11 83 e0 04 c1 e8 02 5b <41> 5e 41 5f c3 cc cc cc cc cc e8 21 86 8c ff eb e8 48 c7 c7 00 4e
RSP: 0018:ffffc9000449f458 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff9034a801 RCX: a3c10a08c3b31c00
RDX: ffffc9000449f501 RSI: ffffffff8be292e0 RDI: ffffffff8be292a0
RBP: dffffc0000000000 R08: ffffc9000449f6e0 R09: 0000000000000000
R10: ffffc9000449f5f8 R11: fffff52000893ec1 R12: ffffc9000449f6f0
R13: ffffffff81728a45 R14: ffffffff8dba6c60 R15: dffffc0000000000
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5882
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
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
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kfree+0x18e/0x440 mm/slub.c:4841
xt_free_table_info+0xf2/0x160 net/netfilter/x_tables.c:1209
__do_replace+0x7a2/0x980 net/ipv6/netfilter/ip6_tables.c:1101
do_replace net/ipv6/netfilter/ip6_tables.c:1158 [inline]
do_ip6t_set_ctl+0xa16/0xce0 net/ipv6/netfilter/ip6_tables.c:1644
nf_setsockopt+0x26c/0x290 net/netfilter/nf_sockopt.c:101
do_sock_setsockopt+0x25a/0x3e0 net/socket.c:2296
__sys_setsockopt net/socket.c:2321 [inline]
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__x64_sys_setsockopt+0x18b/0x220 net/socket.c:2324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f909979085a
RSP: 002b:00007ffdcab263e8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ffdcab26470 RCX: 00007f909979085a
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00000000000003b8 R09: 0079746972756365
R10: 00007f909997ece0 R11: 0000000000000202 R12: 00007f909997ec80
R13: 00007ffdcab2640c R14: 0000000000000000 R15: 00007f9099980e40
rcu: rcu_preempt kthread starved for 10273 jiffies! g53341 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27000 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
__schedule_loop kernel/sched/core.c:6859 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6874
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc7-next-20250526-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: c3 d5 02 00 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 43 45 23 00 f3 0f 1e fa fb f4 98 d5 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6
RAX: 0af309ed43d7db00 RBX: ffffffff81974a08 RCX: 0af309ed43d7db00
RDX: 0000000000000001 RSI: ffffffff8d98094e RDI: ffffffff8be29300
RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa12ef0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50
FS: 0000000000000000(0000) GS:ffff888125c56000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87e08180ec CR3: 00000000284c4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:743
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
rest_init+0x2de/0x300 init/main.c:744
start_kernel+0x47d/0x500 init/main.c:1101
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147