------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 0 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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 49 41 06 fd 5b 41 5e e9 d1 4f a7 06 cc e8 3b 41 06 fd c6 05 17 cc cf 0a 01 90 48 c7 c7 00 65 e1 8b e8 87 ef c9 fc 90 <0f> 0b 90 90 eb d7 e8 1b 41 06 fd c6 05 f8 cb cf 0a 01 90 48 c7 c7 RSP: 0018:ffffc90000007828 EFLAGS: 00010246 RAX: 53dc528b7c407200 RBX: 0000000000000002 RCX: ffffffff8de95280 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc900000079b0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bfaa44 R12: ffff88807fcfc100 R13: dffffc0000000000 R14: ffff88807fcfc26c R15: ffff88807e87c000 FS: 0000000000000000(0000) GS:ffff888125c89000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2aa2b4 CR3: 000000007e33e000 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:raw_spin_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1545 Code: cc e8 91 8d cb 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 eb 16 e8 c4 10 ce 09 e8 7f dc 34 00 fb 5b <41> 5e 41 5f c3 cc cc cc cc cc f3 0f 1e fa 49 be 00 00 00 00 00 fc RSP: 0018:ffffffff8de07b48 EFLAGS: 00000286 RAX: 53dc528b7c407200 RBX: ffff8880b863c5d8 RCX: 53dc528b7c407200 RDX: 0000000000000000 RSI: ffffffff8d96923c RDI: ffffffff8be1af80 RBP: ffffffff8de07d70 R08: ffffffff8f9fd5f7 R09: 1ffffffff1f3fabe R10: dffffc0000000000 R11: fffffbfff1f3fabf R12: ffffffff8de95280 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff8880b863c5d8 __schedule+0x18f5/0x4cb0 kernel/sched/core.c:6789 schedule_idle+0x52/0x90 kernel/sched/core.c:6904 do_idle+0x4ad/0x510 kernel/sched/idle.c:353 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:744 start_kernel+0x47d/0x500 init/main.c:1101 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 ---------------- Code disassembly (best guess): 0: cc int3 1: e8 91 8d cb 09 call 0x9cb8d97 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 41 57 push %r15 19: 41 56 push %r14 1b: 53 push %rbx 1c: eb 16 jmp 0x34 1e: e8 c4 10 ce 09 call 0x9ce10e7 23: e8 7f dc 34 00 call 0x34dca7 28: fb sti 29: 5b pop %rbx * 2a: 41 5e pop %r14 <-- trapping instruction 2c: 41 5f pop %r15 2e: c3 ret 2f: cc int3 30: cc int3 31: cc int3 32: cc int3 33: cc int3 34: f3 0f 1e fa endbr64 38: 49 rex.WB 39: be 00 00 00 00 mov $0x0,%esi 3e: 00 fc add %bh,%ah