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WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#0: syz.7.869/9680
Modules linked in:
CPU: 0 UID: 0 PID: 9680 Comm: syz.7.869 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049
Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 40 81 b7 9a e8 70 b9 82 00 b8 01 00 00 00 87 05 45 f6 14 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 34 01 86 90 48 81 fd 40 36 3d 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000007df0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81a28af0
RDX: fffffbfff356f028 RSI: 0000000000000004 RDI: ffffffff9ab78140
RBP: ffffffff8e3d3640 R08: 0000000000000001 R09: fffffbfff356f028
R10: 0000000000000003 R11: 00000000ffffffff R12: 1ffffffff1c02250
R13: 0000000000000246 R14: ffffffff8e3d3640 R15: ffff8880b843b912
FS: 00007f96d65ef6c0(0000) GS:ffff8881249a1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e39372100 CR3: 000000005fd33000 CR4: 0000000000350ef0
Call Trace:
rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline]
rcu_core+0x461/0x1500 kernel/rcu/tree.c:2852
handle_softirqs+0x219/0x8b0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1055 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1055
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x5a/0x70 kernel/kcov.c:223
Code: 35 8b 82 7c 16 00 00 85 c0 74 2b 8b 82 58 16 00 00 83 f8 02 75 20 48 8b 8a 60 16 00 00 8b 92 5c 16 00 00 48 8b 01 48 83 c0 01 <48> 39 d0 73 07 48 89 01 48 89 34 c1 e9 f0 91 52 ff 0f 1f 44 00 00
RSP: 0018:ffffc90004d17ee0 EFLAGS: 00000216
RAX: 0000000000080000 RBX: 0000000000000001 RCX: ffffc9001f562000
RDX: 0000000000080000 RSI: ffffffff818532fc RDI: ffff888072442718
RBP: ffff888072442600 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: 00000000ffffffff R12: ffff888072442610
R13: ffff88807a5e8ac0 R14: 0000000000000000 R15: 0000000000000000
pid_nr_ns kernel/pid.c:498 [inline]
pid_nr_ns kernel/pid.c:490 [inline]
__task_pid_nr_ns+0x45c/0x500 kernel/pid.c:519
task_tgid_vnr include/linux/pid.h:298 [inline]
__do_sys_getpid+0x1d/0x30 kernel/sys.c:1001
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f96d57865e7
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d b2 62 d9 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 23 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007f96d65eeb08 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007f96d65eec70 RCX: 00007f96d57865e7
RDX: 00007f96d65eeb40 RSI: 00007f96d65eec70 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f96d59e6038 R14: 00007ffe461269d0 R15: 00007ffe46126ab8
----------------
Code disassembly (best guess):
0: 35 8b 82 7c 16 xor $0x167c828b,%eax
5: 00 00 add %al,(%rax)
7: 85 c0 test %eax,%eax
9: 74 2b je 0x36
b: 8b 82 58 16 00 00 mov 0x1658(%rdx),%eax
11: 83 f8 02 cmp $0x2,%eax
14: 75 20 jne 0x36
16: 48 8b 8a 60 16 00 00 mov 0x1660(%rdx),%rcx
1d: 8b 92 5c 16 00 00 mov 0x165c(%rdx),%edx
23: 48 8b 01 mov (%rcx),%rax
26: 48 83 c0 01 add $0x1,%rax
* 2a: 48 39 d0 cmp %rdx,%rax <-- trapping instruction
2d: 73 07 jae 0x36
2f: 48 89 01 mov %rax,(%rcx)
32: 48 89 34 c1 mov %rsi,(%rcx,%rax,8)
36: e9 f0 91 52 ff jmp 0xff52922b
3b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)