rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=4fdc/1/0x4000000000000000 softirq=9781/9782 fqs=5250
	(t=10502 jiffies g=9473 q=11424 ncpus=2)
CPU: 1 PID: 4437 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc900039f7a60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0291c39830ad8c00
RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef760
RBP: ffffc900039f7b80 R08: dffffc0000000000 R09: fffffbfff215c44f
R10: fffffbfff215c44f R11: 1ffffffff215c44e R12: 0000000000000001
R13: 1ffff9200073ef58 R14: 0000000000000246 R15: dffffc0000000000
FS:  00005555561c9500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007e5df000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __might_fault+0xc2/0x120 mm/memory.c:5852
 _copy_from_user+0x27/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:161 [inline]
 restore_altstack+0x9a/0x4a0 kernel/signal.c:4257
 __ia32_sys_rt_sigreturn+0x660/0x790 arch/x86/kernel/signal.c:678
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f86bd98f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc996d7a88 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f86bdbe5fa8 RCX: 00007f86bd98f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f86bdbe5fac
RBP: 0000000000000000 R08: 00235447892703ca R09: 00000007996d7d7f
R10: 0000000000000005 R11: 0000000000000246 R12: 00007f86bdbe5fac
R13: 00007f86bdbe5fa0 R14: 0000000000000095 R15: 0000000000000003
 </TASK>