------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 18437 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 1 UID: 0 PID: 18437 Comm: dhcpcd-run-hook Not tainted 6.15.0-syzkaller-12058-g64980441d269 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Code: 00 00 e8 09 2d ff fc 5b 41 5e e9 d1 4a a7 06 cc e8 fb 2c ff fc c6 05 63 ca c9 0a 01 90 48 c7 c7 c0 38 e2 8b e8 17 db c2 fc 90 <0f> 0b 90 90 eb d7 e8 db 2c ff fc c6 05 44 ca c9 0a 01 90 48 c7 c7
RSP: 0018:ffffc90000a08828 EFLAGS: 00010246
RAX: 283676a59d3e2800 RBX: 0000000000000002 RCX: ffff8880256b1e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000a089b0 R08: ffffffff8fa100f7 R09: 1ffffffff1f4201e
R10: dffffc0000000000 R11: fffffbfff1f4201f R12: ffff888032c12080
R13: dffffc0000000000 R14: ffff888032c121ec R15: ffff888058c61800
FS: 0000000000000000(0000) GS:ffff888125d55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2c909c CR3: 000000008024e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000002
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
get_net include/net/net_namespace.h:268 [inline]
tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
tipc_crypto_xmit+0x1820/0x22c0 net/tipc/crypto.c:1761
tipc_bearer_xmit_skb+0x245/0x400 net/tipc/bearer.c:572
tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338
call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 cb 67 fe 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000455ee30 EFLAGS: 00000206
RAX: 283676a59d3e2800 RBX: 0000000000000202 RCX: 283676a59d3e2800
RDX: 0000000000000003 RSI: ffffffff8db695db RDI: ffffffff8be28340
RBP: ffff8880256b2968 R08: ffffc9000455efb8 R09: 0000000000000000
R10: ffffc9000455f018 R11: fffff520008abe05 R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff8e13f060 R15: ffff8880256b1e00
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
__call_rcu_common kernel/rcu/tree.c:3090 [inline]
call_rcu+0x142/0x990 kernel/rcu/tree.c:3210
slab_free_hook mm/slub.c:2345 [inline]
slab_free mm/slub.c:4643 [inline]
kmem_cache_free+0x309/0x400 mm/slub.c:4745
anon_vma_free mm/rmap.c:137 [inline]
__put_anon_vma+0x12b/0x2d0 mm/rmap.c:2756
put_anon_vma include/linux/rmap.h:117 [inline]
unlink_anon_vmas+0x503/0x670 mm/rmap.c:444
free_pgtables+0x7bf/0xaf0 mm/memory.c:402
exit_mmap+0x444/0xb50 mm/mmap.c:1295
__mmput+0x118/0x420 kernel/fork.c:1121
exec_mmap+0x6ac/0x7d0 fs/exec.c:896
begin_new_exec+0x129c/0x2120 fs/exec.c:1151
load_elf_binary+0x96a/0x2790 fs/binfmt_elf.c:995
search_binary_handler fs/exec.c:1665 [inline]
exec_binprm fs/exec.c:1697 [inline]
bprm_execve+0x99c/0x1450 fs/exec.c:1749
do_execveat_common+0x510/0x6a0 fs/exec.c:1855
do_execve fs/exec.c:1929 [inline]
__do_sys_execve fs/exec.c:2005 [inline]
__se_sys_execve fs/exec.c:2000 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2000
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4fbc0e9107
Code: Unable to access opcode bytes at 0x7f4fbc0e90dd.
RSP: 002b:00007ffc889a0918 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 0000563946a10fe0 RCX: 00007f4fbc0e9107
RDX: 0000563946a11000 RSI: 0000563946a10fe0 RDI: 0000563946a11088
RBP: 0000563946a11088 R08: 00007ffc889a3e8d R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000563946a11000
R13: 00007f4fbc2aee8b R14: 0000563946a11000 R15: 0000000000000000
----------------
Code disassembly (best guess):
0: 51 push %rcx
1: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp)
8: 00 00
a: 9c pushf
b: 8f 44 24 20 pop 0x20(%rsp)
f: f7 44 24 20 00 02 00 testl $0x200,0x20(%rsp)
16: 00
17: 75 56 jne 0x6f
19: f7 c3 00 02 00 00 test $0x200,%ebx
1f: 74 01 je 0x22
21: fb sti
22: 65 48 8b 05 cb 67 fe mov %gs:0x10fe67cb(%rip),%rax # 0x10fe67f5
29: 10
* 2a: 48 3b 44 24 28 cmp 0x28(%rsp),%rax <-- trapping instruction
2f: 0f 85 8b 00 00 00 jne 0xc0
35: 48 83 c4 30 add $0x30,%rsp
39: 5b pop %rbx
3a: 41 5c pop %r12
3c: 41 5d pop %r13
3e: 41 5e pop %r14