From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Christian de Rivaz Subject: AX25 mkiss interface not deleted when the serial port is removed Date: Fri, 25 Sep 2015 19:21:18 +0200 Message-ID: <5605828E.5010104@eclis.ch> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-hams-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: linux-hams@vger.kernel.org Hello, On a embedded system we use AX25 over an USB serial port with the kissattach command. For some hardware reason the microcontroller that act as a TNC and USB CDC device can be rested while the system is running, causing a USB disconnect of the USN CDC device and the removal of the corresponding serial port in the kernel. But the ax0 interface is not removed in this case and after a few seconds the kernel panic with the crash below: [] (skb_panic) from [] (skb_push+0x4c/0x50) [] (skb_push) from [] (ax25_hard_header+0x34/0xf4 [ax25]) [] (ax25_hard_header [ax25]) from [] (ax_header+0x38/0x40 [mkiss]) [] (ax_header [mkiss]) from [] (neigh_compat_output+0x8c/0xd8) [] (neigh_compat_output) from [] (ip_finish_output+0x2a0/0x914) [] (ip_finish_output) from [] (ip_output+0xd8/0xf0) [] (ip_output) from [] (ip_local_out_sk+0x44/0x48) [] (ip_local_out_sk) from [] (igmpv3_sendpack+0x54/0x58) [] (igmpv3_sendpack) from [] (igmp_ifc_timer_expire+0x1c0/0x2ac) [] (igmp_ifc_timer_expire) from [] (call_timer_fn+0x4c/0x1ac) [] (call_timer_fn) from [] (run_timer_softirq+0x21c/0x340) [] (run_timer_softirq) from [] (__do_softirq+0xa4/0x370) [] (__do_softirq) from [] (irq_exit+0x88/0xc4) [] (irq_exit) from [] (__handle_domain_irq+0x74/0xdc) [] (__handle_domain_irq) from [] (aic5_handle+0xe8/0xf4) [] (aic5_handle) from [] (__irq_usr+0x48/0x60) I suspect that some code is missing somewhere in the serial port release part to remove the AX25 interface that is attached to it. But I am not certain about this, and I don't know where to look into the kernel to fix this. The kernel version is 3.19.0 running on a ARMv7 processor in case that matter. Any hint would be appreciate. Best Regards, Jean-Christian de Rivaz