Re: [PATCH] firmware: stratix10-rsu: Fix NULL pointer dereference when RSU is disabled

[Dinh Nguyen <dinguyen@kernel.org>]

On 2/11/26 22:00, Liwei Song wrote:
> When the Remote System Update (RSU) isn't enabled in the First Stage
> Boot Loader (FSBL), the driver encounters a NULL pointer dereference when
> excute svc_normal_to_secure_thread() thread, resulting in a kernel panic:
> 
> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
> Mem abort info:
> ...
> Data abort info:
> ...
> [0000000000000008] user address but active_mm is swapper
> Internal error: Oops: 0000000096000004 [#1]  SMP
> Modules linked in:
> CPU: 0 UID: 0 PID: 79 Comm: svc_smc_hvc_thr Not tainted 6.19.0-rc8-yocto-standard+ #59 PREEMPT
> Hardware name: SoCFPGA Stratix 10 SoCDK (DT)
> pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : svc_normal_to_secure_thread+0x38c/0x990
> lr : svc_normal_to_secure_thread+0x144/0x990
> ...
> Call trace:
>   svc_normal_to_secure_thread+0x38c/0x990 (P)
>   kthread+0x150/0x210
>   ret_from_fork+0x10/0x20
> Code: 97cfc113 f9400260 aa1403e1 f9400400 (f9400402)
> ---[ end trace 0000000000000000 ]---
> 
> The issue occurs because rsu_send_async_msg() fails when RSU is not enabled
> in firmware, causing the channel to be freed via stratix10_svc_free_channel().
> However, the probe function continues execution and registers
> svc_normal_to_secure_thread(), which subsequently attempts to access the
> already-freed channel, triggering the NULL pointer dereference.
> 
> Fix this by properly cleaning up the async client and returning early on
> failure, preventing the thread from being used with an invalid channel.
> 
> Fixes: 15847537b623 ("firmware: stratix10-rsu: Migrate RSU driver to use stratix10 asynchronous framework.")
> Signed-off-by: Liwei Song <liwei.song@windriver.com>
> ---

Applied!

Thanks,
Dinh