netdev - Re: [PATCH net 3/6] can: mcp251xfd: mcp251xfd_remove(): fix order of unregistration calls

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f9c7881f-b568-4d06-8266-0aa602edfcbc@intel.com>
Date: Tue, 6 May 2025 11:28:31 -0700
From: Jacob Keller <jacob.e.keller@...el.com>
To: Marc Kleine-Budde <mkl@...gutronix.de>, <netdev@...r.kernel.org>
CC: <davem@...emloft.net>, <kuba@...nel.org>, <linux-can@...r.kernel.org>,
	<kernel@...gutronix.de>, <stable@...r.kernel.org>
Subject: Re: [PATCH net 3/6] can: mcp251xfd: mcp251xfd_remove(): fix order of
 unregistration calls



On 5/6/2025 6:56 AM, Marc Kleine-Budde wrote:
> If a driver is removed, the driver framework invokes the driver's
> remove callback. A CAN driver's remove function calls
> unregister_candev(), which calls net_device_ops::ndo_stop further down
> in the call stack for interfaces which are in the "up" state.
> 
> With the mcp251xfd driver the removal of the module causes the
> following warning:
> 
> | WARNING: CPU: 0 PID: 352 at net/core/dev.c:7342 __netif_napi_del_locked+0xc8/0xd8
> 
> as can_rx_offload_del() deletes the NAPI, while it is still active,
> because the interface is still up.
> 
> To fix the warning, first unregister the network interface, which
> calls net_device_ops::ndo_stop, which disables the NAPI, and then call
> can_rx_offload_del().
> 
> Fixes: 55e5b97f003e ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN")
> Cc: stable@...r.kernel.org
> Link: https://patch.msgid.link/20250502-can-rx-offload-del-v1-1-59a9b131589d@pengutronix.de
> Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
> ---

Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>