vcan0: j1939_tp_rxtimer: 0xffff888034beb800: rx timeout, send abort vcan0: j1939_tp_rxtimer: 0xffff888034beb800: abort rx timeout. Force session deactivation ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 0 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28 Code: 60 ef 5f 8c e8 87 fc a0 fc 90 0f 0b 90 90 eb 99 e8 eb 06 e0 fc c6 05 ff d6 50 0b 01 90 48 c7 c7 c0 ef 5f 8c e8 67 fc a0 fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 c8 06 e0 fc c6 05 d9 d6 50 0b 01 90 RSP: 0018:ffffc90000007c08 EFLAGS: 00010246 RAX: 14ca8013cdc76700 RBX: ffff88802fdd6ae4 RCX: ffffffff8e694640 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff8155d222 R09: 1ffff92000000f1c R10: dffffc0000000000 R11: fffff52000000f1d R12: ffff888034beb868 R13: ffff88802fdd6ae4 R14: 1ffff1100697d718 R15: ffff888034beb800 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb82b948100 CR3: 000000007e7f0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kfree_skb_reason include/linux/skbuff.h:1262 [inline] kfree_skb include/linux/skbuff.h:1271 [inline] j1939_session_destroy net/can/j1939/transport.c:282 [inline] __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put+0x1ed/0x440 net/can/j1939/transport.c:299 j1939_tp_rxtimer+0x184/0x3d0 net/can/j1939/transport.c:1265 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1772 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 80 d7 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 55 27 ab 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e607ca8 EFLAGS: 00000246 RAX: ffffffff8e694640 RBX: ffff8880202fc864 RCX: 000000000004edf9 RDX: 0000000000000001 RSI: ffff8880202fc800 RDI: ffff8880202fc864 RBP: 000000000003a978 R08: ffff8880b8637e9b R09: 1ffff110170c6fd3 R10: dffffc0000000000 R11: ffffffff8bbeda00 R12: ffff888020bd8000 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff8f11c460 acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:264 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:385 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:326 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424 rest_init+0x2dc/0x300 init/main.c:747 start_kernel+0x47f/0x500 init/main.c:1105 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 65 48 8b 04 25 80 d7 mov %gs:0x3d780,%rax 10: 03 00 12: 48 f7 00 08 00 00 00 testq $0x8,(%rax) 19: 75 10 jne 0x2b 1b: 66 90 xchg %ax,%ax 1d: 0f 00 2d 55 27 ab 00 verw 0xab2755(%rip) # 0xab2779 24: f3 0f 1e fa endbr64 28: fb sti 29: f4 hlt * 2a: fa cli <-- trapping instruction 2b: c3 ret 2c: cc int3 2d: cc int3 2e: cc int3 2f: cc int3 30: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 37: 00 00 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop