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: 6848 Comm: syz-fuzzer Not tainted 5.9.0-rc3-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 74 3f 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: ffff88821485a008 RCX: 0000000000000002 RDX: 0000000000000066 RSI: ffffffff871d0b8c RDI: 0000000000000330 RBP: ffffffff8d5382a0 R08: 0000000000000001 R09: ffffffff8c5f4aff R10: fffffbfff18be95f R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000104 R15: 0000000000000000 FS: 000000c00003eb10(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056457d552db8 CR3: 0000000097b7d000 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+0x1f7/0xa91 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+0x235/0x280 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: 0033:0x78dd3c Code: 48 8b 54 24 20 48 8b 5c 24 18 48 8d 35 9d d2 0d 00 48 39 f3 75 4f 48 8b 1a 48 8b 4a 08 48 39 c8 73 3e 48 c1 e0 04 48 8b 0c 03 <48> 8b 49 58 48 8b 44 03 08 48 89 04 24 ff d1 48 8b 44 24 08 48 89 RSP: 002b:000000c01410c348 EFLAGS: 00000206 RAX: 0000000000009700 RBX: 000000c000390000 RCX: 0000000000b246e0 RDX: 000000c00000ce20 RSI: 000000000086afc0 RDI: 000000c00deb9300 RBP: 000000c01410c370 R08: 0000000000b1f000 R09: 0000000000b1ef00 R10: 0000000000000002 R11: 0000000000000011 R12: 00000000000000f1 R13: 0000000000000000 R14: 0000000000adac76 R15: 0000000000000000 Modules linked in: ---[ end trace 02f40a3f11fb01e7 ]--- 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 74 3f 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: ffff88821485a008 RCX: 0000000000000002 RDX: 0000000000000066 RSI: ffffffff871d0b8c RDI: 0000000000000330 RBP: ffffffff8d5382a0 R08: 0000000000000001 R09: ffffffff8c5f4aff R10: fffffbfff18be95f R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000104 R15: 0000000000000000 FS: 000000c00003eb10(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056457d552db8 CR3: 0000000097b7d000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400