rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=9285, q=38 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294957798-4294947296), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g9285 f0x2 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:27528 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5813 Comm: syz-executor260 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_acquire+0x26/0x7c80 kernel/locking/lockdep.c:4993
Code: 1f 44 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 20 02 00 00 45 89 cd 45 89 c4 89 4c 24 18 <89> 54 24 70 41 89 f7 65 48 8b 04 25 28 00 00 00 48 89 84 24 00 02
RSP: 0018:ffffc9000469f800 EFLAGS: 00000086
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880264c14a0
RBP: ffffc9000469fa48 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1c9509e R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000246 R15: dffffc0000000000
FS:  0000555566c743c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f04c270db60 CR3: 00000000774cd000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __might_fault+0xc6/0x120 mm/memory.c:5946
 _copy_from_user+0x2a/0xe0 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:183 [inline]
 restore_altstack+0x9e/0x4a0 kernel/signal.c:4290
 __ia32_sys_rt_sigreturn+0x1f6/0x7b0 arch/x86/kernel/signal_64.c:263
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f04c270db69
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007ffebd4a4f80 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04c270db69
RDX: 00007ffebd4a4f80 RSI: 00007ffebd4a50b0 RDI: 0000000000000021
RBP: 0000000000000000 R08: 00007f04c26ae990 R09: 00007f04c26ae990
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f04c274cddc
R13: 00007f04c2746116 R14: 00007ffebd4a5540 R15: 0000000000000000
 </TASK>