general protection fault, probably for non-canonical address 0xdffffc0000000066: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000330-0x0000000000000337] CPU: 1 PID: 6846 Comm: syz-fuzzer Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ax25_dev_ax25dev include/net/ax25.h:337 [inline] RIP: 0010:ax25_send_frame+0xe4/0x640 net/ax25/ax25_out.c:56 Code: 00 48 85 c0 49 89 c4 0f 85 fb 03 00 00 e8 e4 ea 57 fa 49 8d bd 30 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b1 04 00 00 4d 8b ad 30 03 00 00 4d 85 ed 0f 84 RSP: 0000:ffffc90000da8ac0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff88809901a808 RCX: 0000000000000002 RDX: 0000000000000066 RSI: ffffffff871c542c RDI: 0000000000000330 RBP: ffffffff8d537220 R08: 0000000000000001 R09: ffffffff8c5f3b27 R10: fffffbfff18be764 R11: 1ffffffff1840d73 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000104 R15: 0000000000000000 FS: 000000c00003e790(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004ea750 CR3: 000000009e855000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rose_send_frame+0xcc/0x2f0 net/rose/rose_link.c:106 rose_transmit_clear_request+0x1d5/0x290 net/rose/rose_link.c:255 rose_rx_call_request+0x4bd/0x1978 net/rose/af_rose.c:998 rose_loopback_timer+0x15d/0x470 net/rose/rose_loopback.c:100 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0033:0x41fa09 Code: 5c 24 50 48 89 5c 24 10 48 89 4c 24 18 48 8b 8c 24 98 00 00 00 48 89 4c 24 20 48 89 54 24 28 e8 dd 03 00 00 eb 94 49 01 52 10 <4d> 01 5a 18 48 8b ac 24 80 00 00 00 48 81 c4 88 00 00 00 c3 4c 39 RSP: 002b:000000c000049ea0 EFLAGS: 00000206 RAX: 0000000000203001 RBX: 00007ff8d6c4a991 RCX: 0000000000000040 RDX: 0000000000000040 RSI: 0000000000000003 RDI: 0000000000000040 RBP: 000000c000049f20 R08: 00007ff8d6c72fff R09: 000000c007af3200 R10: 000000c00002d698 R11: 0000000000000040 R12: 00000000000000fa R13: 0000000000000000 R14: 0000000000ada43b R15: 0000000000000000 Modules linked in: ---[ end trace 794c92002e7905d4 ]--- RIP: 0010:ax25_dev_ax25dev include/net/ax25.h:337 [inline] RIP: 0010:ax25_send_frame+0xe4/0x640 net/ax25/ax25_out.c:56 Code: 00 48 85 c0 49 89 c4 0f 85 fb 03 00 00 e8 e4 ea 57 fa 49 8d bd 30 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b1 04 00 00 4d 8b ad 30 03 00 00 4d 85 ed 0f 84 RSP: 0000:ffffc90000da8ac0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff88809901a808 RCX: 0000000000000002 RDX: 0000000000000066 RSI: ffffffff871c542c RDI: 0000000000000330 RBP: ffffffff8d537220 R08: 0000000000000001 R09: ffffffff8c5f3b27 R10: fffffbfff18be764 R11: 1ffffffff1840d73 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000104 R15: 0000000000000000 FS: 000000c00003e790(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004ea750 CR3: 000000009e855000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400