Hello, syzbot found the following issue on: HEAD commit: d7c4c9e075f8 ax25: fix incorrect dev_tracker usage git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=123a0cde080000 kernel config: https://syzkaller.appspot.com/x/.config?x=26034e6fe0075dad dashboard link: https://syzkaller.appspot.com/bug?extid=dc42341ea62e8eb6c1f7 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+dc42341ea62e8eb6c1f7@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 32332 Comm: kworker/0:4 Not tainted 5.19.0-rc8-syzkaller-00103-gd7c4c9e075f8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Workqueue: events_power_efficient neigh_managed_work RIP: 0010:br_nf_pre_routing_finish+0x200/0x1ad0 net/bridge/br_netfilter_hooks.c:360 Code: 83 c0 01 38 d0 7c 08 84 d2 0f 85 e3 12 00 00 48 8d 7b 02 45 0f b7 74 24 3e 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 b9 RSP: 0018:ffffc90000007868 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 0000000000000000 RSI: ffffffff883fc456 RDI: 0000000000000002 RBP: ffff88801d0ee000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807e999000 R13: 0000000000000010 R14: 00000000000005dc R15: ffff888074392800 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fde65908d64 CR3: 000000004d41b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] br_nf_pre_routing+0xae3/0x1f00 net/bridge/br_netfilter_hooks.c:531 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_bridge_pre net/bridge/br_input.c:255 [inline] br_handle_frame+0x8df/0x1280 net/bridge/br_input.c:399 __netif_receive_skb_core+0xa13/0x3920 net/core/dev.c:5378 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5482 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5598 process_backlog+0x3a0/0x7c0 net/core/dev.c:5926 __napi_poll+0xb3/0x6e0 net/core/dev.c:6492 napi_poll net/core/dev.c:6559 [inline] net_rx_action+0x9c1/0xd90 net/core/dev.c:6670 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571 do_softirq.part.0+0xde/0x130 kernel/softirq.c:472 </IRQ> <TASK> do_softirq kernel/softirq.c:464 [inline] __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:396 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:br_nf_pre_routing_finish+0x200/0x1ad0 net/bridge/br_netfilter_hooks.c:360 Code: 83 c0 01 38 d0 7c 08 84 d2 0f 85 e3 12 00 00 48 8d 7b 02 45 0f b7 74 24 3e 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 b9 RSP: 0018:ffffc90000007868 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 0000000000000000 RSI: ffffffff883fc456 RDI: 0000000000000002 RBP: ffff88801d0ee000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807e999000 R13: 0000000000000010 R14: 00000000000005dc R15: ffff888074392800 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fde65908d64 CR3: 000000004d41b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 83 c0 01 add $0x1,%eax 3: 38 d0 cmp %dl,%al 5: 7c 08 jl 0xf 7: 84 d2 test %dl,%dl 9: 0f 85 e3 12 00 00 jne 0x12f2 f: 48 8d 7b 02 lea 0x2(%rbx),%rdi 13: 45 0f b7 74 24 3e movzwl 0x3e(%r12),%r14d 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 01 add $0x1,%eax 37: 38 d0 cmp %dl,%al 39: 7c 08 jl 0x43 3b: 84 d2 test %dl,%dl 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: b9 .byte 0xb9 --- This report is generated by a bot. 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