Re: [PATCH net] nfp: Check resource mutex allocation

[Simon Horman]

On Wed, Jul 08, 2026 at 10:34:08PM +0800, Ruoyu Wang wrote:
> nfp_cpp_resource_find() allocates a CPP mutex handle for the matching
> resource-table entry and then reports success.  nfp_resource_try_acquire()
> immediately passes that handle to nfp_cpp_mutex_trylock().
> 
> However, nfp_cpp_mutex_alloc() returns NULL on failure.  If that happens
> for a matching table entry, the resource lookup still returns success and
> the following trylock dereferences a NULL mutex pointer while opening the
> resource.
> 
> nfp_resource_acquire() already treats failure to allocate the table mutex
> as -ENOMEM.  Do the same for the resource mutex and fail the lookup before
> publishing the rest of the resource handle.
> 
> This issue was found by a static analysis checker and confirmed by
> manual source review.
> 
> Fixes: f01a2161577d ("nfp: add support for resources")
> Signed-off-by: Ruoyu Wang <ruoyuw560@xxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>