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WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049, CPU#1: syz.0.5211/18561
Modules linked in:
CPU: 1 UID: 0 PID: 18561 Comm: syz.0.5211 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049
Code: ff ff 48 c7 c7 e0 74 73 9a be 04 00 00 00 e8 53 d1 83 00 4c 89 f7 b8 01 00 00 00 87 05 e5 d6 c6 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 80 31 b6 8e 74 47 48 c7 c0 e0 74 54 90 48 c1 e8
RSP: 0018:ffffc90000a08d98 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff81ac9ded
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8eb63180
RBP: ffffc90000a08f18 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff34e6e9c R12: 0000000000002904
R13: dffffc0000000000 R14: ffffffff8eb63180 R15: dffffc0000000000
FS: 00007fcd008096c0(0000) GS:ffff888124ee2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fae4844eddd CR3: 00000000356fa000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_core+0x3fe/0x1070 kernel/rcu/tree.c:2864
handle_softirqs+0x22a/0x870 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:739
irq_exit_rcu+0x9/0x30 kernel/softirq.c:756
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:syscall_enter_from_user_mode_work include/linux/entry-common.h:155 [inline]
RIP: 0010:syscall_enter_from_user_mode include/linux/entry-common.h:187 [inline]
RIP: 0010:do_syscall_64+0xa8/0xf80 arch/x86/entry/syscall_64.c:90
Code: 00 48 8b 7d 08 48 89 7b 08 e8 a4 83 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 f4 3f 10 f6 90 90 e8 9d 3f 10 f6 fb 4d 8b 6f 08 <41> f6 c5 bf 74 7b 41 f6 c5 20 74 12 4c 89 f7 e8 64 31 f1 f5 41 bc
RSP: 0018:ffffc9000201fef0 EFLAGS: 00000202
RAX: 0000000004f8a443 RBX: ffffc9000201fef0 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e257836 RDI: ffffffff8c4a6280
RBP: ffffc9000201ff38 R08: ffffffff905441f7 R09: 1ffffffff20a883e
R10: dffffc0000000000 R11: fffffbfff20a883f R12: 000000000000000f
R13: 0000000000000000 R14: ffffc9000201ff48 R15: ffff88807b9abd00
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fccff93db19
Code: 11 06 00 66 2e 0f 1f 84 00 00 00 00 00 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 0c 25
RSP: 002b:00007fcd00808a80 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007fccffc15fa0 RCX: 00007fccff93db19
RDX: 00007fcd00808a80 RSI: 00007fcd00808bb0 RDI: 0000000000000021
RBP: 00007fccffa32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fccffc16038 R14: 00007fccffc15fa0 R15: 00007ffc43230628
----------------
Code disassembly (best guess):
0: 00 48 8b add %cl,-0x75(%rax)
3: 7d 08 jge 0xd
5: 48 89 7b 08 mov %rdi,0x8(%rbx)
9: e8 a4 83 00 00 call 0x83b2
e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
18: 90 nop
19: e8 f4 3f 10 f6 call 0xf6104012
1e: 90 nop
1f: 90 nop
20: e8 9d 3f 10 f6 call 0xf6103fc2
25: fb sti
26: 4d 8b 6f 08 mov 0x8(%r15),%r13
* 2a: 41 f6 c5 bf test $0xbf,%r13b <-- trapping instruction
2e: 74 7b je 0xab
30: 41 f6 c5 20 test $0x20,%r13b
34: 74 12 je 0x48
36: 4c 89 f7 mov %r14,%rdi
39: e8 64 31 f1 f5 call 0xf5f131a2
3e: 41 rex.B
3f: bc .byte 0xbc