------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xf4/0x130 lib/refcount.c:28, CPU#2: swapper/2/0
Modules linked in:
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 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:refcount_warn_saturate+0xf4/0x130 lib/refcount.c:28
Code: cc e8 d0 39 e5 fc 48 8d 3d 89 02 2a 0c 67 48 0f b9 3a e8 bf 39 e5 fc 5b 5d e9 48 1f a8 06 e8 b3 39 e5 fc 48 8d 3d 7c 02 2a 0c <67> 48 0f b9 3a e8 a2 39 e5 fc 5b 5d c3 cc cc cc cc e8 96 39 e5 fc
RSP: 0000:ffffc90000558c18 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88806bce9820 RCX: 0000000000000101
RDX: ffff88801cbc8000 RSI: ffffffff8525e69d RDI: ffffffff914fe920
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000004
R10: 0000000000000003 R11: 0000000000000001 R12: ffff88806bce9820
R13: 8000000000000101 R14: 1ffff920000ab18d R15: ffffffff8b00de60
FS: 0000000000000000(0000) GS:ffff888096b76000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f548cda4 CR3: 0000000056e53000 CR4: 0000000000352ef0
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
sctp_transport_put+0x134/0x180 net/sctp/transport.c:476
call_timer_fn+0x198/0x5f0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2405
handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x194/0x210 kernel/softirq.c:767
irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 28 a0 02 e9 43 4f 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 e5 20 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0000:ffffc9000049fe00 EFLAGS: 00000202
RAX: 0000000000e027a1 RBX: ffff88801cbc8000 RCX: ffffffff8bcad115
RDX: 0000000000000001 RSI: ffffffff8e3e64a5 RDI: ffffffff8c61e280
RBP: ffffed1003979000 R08: 0000000000000001 R09: ffffed10056867bd
R10: ffff88802b433deb R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000093fc4 R15: dffffc0000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:768
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x158
----------------
Code disassembly (best guess):
0: cc int3
1: e8 d0 39 e5 fc call 0xfce539d6
6: 48 8d 3d 89 02 2a 0c lea 0xc2a0289(%rip),%rdi # 0xc2a0296
d: 67 48 0f b9 3a ud1 (%edx),%rdi
12: e8 bf 39 e5 fc call 0xfce539d6
17: 5b pop %rbx
18: 5d pop %rbp
19: e9 48 1f a8 06 jmp 0x6a81f66
1e: e8 b3 39 e5 fc call 0xfce539d6
23: 48 8d 3d 7c 02 2a 0c lea 0xc2a027c(%rip),%rdi # 0xc2a02a6
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: e8 a2 39 e5 fc call 0xfce539d6
34: 5b pop %rbx
35: 5d pop %rbp
36: c3 ret
37: cc int3
38: cc int3
39: cc int3
3a: cc int3
3b: e8 96 39 e5 fc call 0xfce539d6