------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 4040 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 0 UID: 0 PID: 4040 Comm: syz-executor 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:ffffc90000007828 EFLAGS: 00010246
RAX: 8cd9b3a442455f00 RBX: 0000000000000002 RCX: ffff8880616b9e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000079b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfaa44 R12: ffff8880797c2080
R13: dffffc0000000000 R14: ffff8880797c21ec R15: ffff88805db29400
FS: 0000555593c86500(0000) GS:ffff888125c55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5464df6d00 CR3: 0000000060278000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 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:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:745
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 0c a7 7c 00 48 c7 c3 58 df 9d 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d 89 89 f5 10 74 11 83 e0 04 c1 e8 02 5b
RSP: 0018:ffffc90004e07310 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffff8880b8632f58 RCX: 8cd9b3a442455f00
RDX: ffff8880616b9e00 RSI: ffffffff8be28320 RDI: ffffffff8be282e0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822f04fa
R10: dffffc0000000000 R11: fffff940002330a1 R12: dffffc0000000000
R13: 0000000000000008 R14: ffffffff8dba1c60 R15: dffffc0000000000
rcu_read_unlock_sched include/linux/rcupdate.h:951 [inline]
pfn_valid+0x340/0x490 include/linux/mmzone.h:2168
page_table_check_set+0x25/0x730 mm/page_table_check.c:105
page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
set_ptes include/linux/pgtable.h:292 [inline]
__copy_present_ptes mm/memory.c:973 [inline]
copy_present_ptes mm/memory.c:1056 [inline]
copy_pte_range mm/memory.c:1179 [inline]
copy_pmd_range+0x4262/0x7000 mm/memory.c:1267
copy_pud_range mm/memory.c:1304 [inline]
copy_p4d_range mm/memory.c:1328 [inline]
copy_page_range+0xc46/0x1270 mm/memory.c:1416
dup_mmap+0xf57/0x1ac0 mm/mmap.c:1838
dup_mm kernel/fork.c:1477 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1529
copy_process+0x1706/0x3c00 kernel/fork.c:2169
kernel_clone+0x21e/0x870 kernel/fork.c:2599
__do_sys_clone kernel/fork.c:2742 [inline]
__se_sys_clone kernel/fork.c:2726 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726
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: 0033:0x7f26b838fc12
Code: 85 ff 74 3e 48 83 e6 f0 74 38 48 89 4e f8 48 83 ee 10 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 7c 13 74 01 c3 31 ed 58 5f ff d0 48 89 c7 b8 3c 00 00 00
RSP: 002b:00007fff94fd87e8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f26b85b5f40 RCX: 00007f26b838fc12
RDX: 0000000000000001 RSI: 00007f26b86dffb0 RDI: 0000000030000000
RBP: 00007f26b85b6738 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fff94fd8ad8 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
----------------
Code disassembly (best guess):
0: f0 48 c1 e8 03 lock shr $0x3,%rax
5: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
a: 74 08 je 0x14
c: 4c 89 f7 mov %r14,%rdi
f: e8 0c a7 7c 00 call 0x7ca720
14: 48 c7 c3 58 df 9d 92 mov $0xffffffff929ddf58,%rbx
1b: 49 03 1e add (%r14),%rbx
1e: 48 89 d8 mov %rbx,%rax
21: 48 c1 e8 03 shr $0x3,%rax
25: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax
* 2a: 84 c0 test %al,%al <-- trapping instruction
2c: 75 34 jne 0x62
2e: 8b 03 mov (%rbx),%eax
30: 65 ff 0d 89 89 f5 10 decl %gs:0x10f58989(%rip) # 0x10f589c0
37: 74 11 je 0x4a
39: 83 e0 04 and $0x4,%eax
3c: c1 e8 02 shr $0x2,%eax
3f: 5b pop %rbx