------------[ cut here ]------------ 1 WARNING: kernel/rcu/tree_stall.h:1048 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048, CPU#2: syz.2.3982/22326 Modules linked in: CPU: 2 UID: 0 PID: 22326 Comm: syz.2.3982 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048 Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 80 65 72 9b e8 10 1d 8b 00 b8 01 00 00 00 87 05 a5 27 84 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 84 eb 21 91 48 81 fd 40 33 bf 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000538df0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ee3dd0 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b726580 RBP: ffffffff8ebf3340 R08: 0000000000000001 R09: fffffbfff36e4cb0 R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1d01e50 R13: 0000000000000246 R14: 0000000000000020 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888096df3000(0063) knlGS:00000000f5496b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f735d31c CR3: 0000000055c01000 CR4: 0000000000352ef0 Call Trace: rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1011 [inline] rcu_core+0x2cb/0x10d0 kernel/rcu/tree.c:2892 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x5ab/0x1870 kernel/smp.c:912 Code: 01 c5 41 83 c4 03 e8 44 92 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 8b 45 08 31 ff 83 e0 01 41 89 c6 <89> c6 e8 8e 8c 0c 00 45 85 f6 75 d0 e8 14 92 0c 00 e8 0f 92 0c 00 RSP: 0018:ffffc900056079c8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffc90031f45000 RDX: 0000000000080000 RSI: ffffffff81fd2ebc RDI: 0000000000000000 RBP: ffff88802b243360 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed100564866d R14: 0000000000000001 R15: ffff88802b43c9c0 clock_was_set+0x61c/0x850 kernel/time/hrtimer.c:999 do_adjtimex+0x302/0x370 kernel/time/timekeeping.c:3006 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime32+0x1c4/0x280 kernel/time/posix-timers.c:1325 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fd6fec Code: Unable to access opcode bytes at 0xf7fd6fc2. RSP: 002b:00000000f549650c EFLAGS: 00000292 ORIG_RAX: 0000000000000157 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000080000340 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 01 c5 add %eax,%ebp 2: 41 83 c4 03 add $0x3,%r12d 6: e8 44 92 0c 00 call 0xc924f b: f3 90 pause d: 41 0f b6 45 00 movzbl 0x0(%r13),%eax 12: 41 38 c4 cmp %al,%r12b 15: 7c 08 jl 0x1f 17: 84 c0 test %al,%al 19: 0f 85 a8 10 00 00 jne 0x10c7 1f: 8b 45 08 mov 0x8(%rbp),%eax 22: 31 ff xor %edi,%edi 24: 83 e0 01 and $0x1,%eax 27: 41 89 c6 mov %eax,%r14d * 2a: 89 c6 mov %eax,%esi <-- trapping instruction 2c: e8 8e 8c 0c 00 call 0xc8cbf 31: 45 85 f6 test %r14d,%r14d 34: 75 d0 jne 0x6 36: e8 14 92 0c 00 call 0xc924f 3b: e8 0f 92 0c 00 call 0xc924f