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WARNING: CPU: 1 PID: 10520 at kernel/rcu/tree_stall.h:970 rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:962
Modules linked in:
CPU: 1 PID: 10520 Comm: syz.0.1904 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:970
Code: ff ff ff 48 c7 c7 20 df c2 96 be 04 00 00 00 e8 7a 4c 65 00 48 89 df b8 01 00 00 00 87 05 bc 39 57 15 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 40 01 b3 8c 74 47 48 c7 c0 e4 ab 1f 8e 48 c1 e8 03
RSP: 0018:ffffc900001e0b78 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffff8cb30140 RCX: ffffffff816ba556
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8cb30140
RBP: ffffc900001e0df0 R08: 0000000000000004 R09: 0000000000000003
R10: fffffbfff2d85be4 R11: 1ffffffff2d85be4 R12: 0000000000002904
R13: dffffc0000000000 R14: 0000000000000a06 R15: dffffc0000000000
FS: 00007fe8a5ab86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe8a5ab8000 CR3: 000000004ff5c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_core+0x5d9/0x16a0 kernel/rcu/tree.c:2552
handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
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:ffffc90017a07a60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: e6cf7aac5a023d00
RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefce0
RBP: ffffc90017a07b80 R08: dffffc0000000000 R09: fffffbfff215c44f
R10: fffffbfff215c44f R11: 1ffffffff215c44e R12: 0000000000000001
R13: 1ffff92002f40f58 R14: 0000000000000246 R15: dffffc0000000000
__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: 0033:0x7fe8a4b8eec9
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:00007fe8a5ab80e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007fe8a4de5fa8 RCX: 00007fe8a4b8eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe8a4de5fa8
RBP: 00007fe8a4de5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe8a4de6038 R14: 00007ffd4e19f830 R15: 00007ffd4e19f918
----------------
Code disassembly (best guess):
0: 00 9c 8f 84 24 80 00 add %bl,0x802484(%rdi,%rcx,4)
7: 00 00 add %al,(%rax)
9: f6 84 24 81 00 00 00 testb $0x2,0x81(%rsp)
10: 02
11: 0f 85 f5 00 00 00 jne 0x10c
17: 41 f7 c6 00 02 00 00 test $0x200,%r14d
1e: 74 01 je 0x21
20: fb sti
21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp)
28: e0 45
* 2a: 4b c7 44 3d 00 00 00 movq $0x0,0x0(%r13,%r15,1) <-- trapping instruction
31: 00 00
33: 66 43 c7 44 3d 09 00 movw $0x0,0x9(%r13,%r15,1)
3a: 00
3b: 43 rex.XB
3c: c6 .byte 0xc6
3d: 44 rex.R
3e: 3d .byte 0x3d
3f: 0b .byte 0xb