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: 7146 Comm: kworker/1:4 Not tainted 5.9.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events iterate_cleanup_work 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 f4 43 56 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: 0018:ffffc90000da8ac0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff888214f43008 RCX: 0000000000000002 RDX: 0000000000000066 RSI: ffffffff871e305c RDI: 0000000000000330 RBP: ffffffff8d5444e0 R08: 0000000000000001 R09: ffffffff8c600b37 R10: fffffbfff18c0166 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000104 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d127000 CR3: 000000009df45000 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 do_softirq kernel/softirq.c:343 [inline] do_softirq+0x154/0x1b0 kernel/softirq.c:330 __local_bh_enable_ip+0x196/0x1f0 kernel/softirq.c:195 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2226 [inline] nf_ct_iterate_cleanup+0x9e/0x330 net/netfilter/nf_conntrack_core.c:2249 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2334 [inline] nf_ct_iterate_cleanup_net+0x113/0x170 net/netfilter/nf_conntrack_core.c:2319 iterate_cleanup_work+0x45/0x130 net/netfilter/nf_nat_masquerade.c:216 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: ---[ end trace 7f548697cbb8eaf2 ]--- 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 f4 43 56 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: 0018:ffffc90000da8ac0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff888214f43008 RCX: 0000000000000002 RDX: 0000000000000066 RSI: ffffffff871e305c RDI: 0000000000000330 RBP: ffffffff8d5444e0 R08: 0000000000000001 R09: ffffffff8c600b37 R10: fffffbfff18c0166 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000104 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d127000 CR3: 000000009df45000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400