Re: [PATCH] slab: Saturate to SIZE_MAX for allocation size overflows

[Vlastimil Babka (SUSE)]

On 2/25/26 08:15, Kees Cook wrote:
> On Wed, Feb 25, 2026 at 03:59:08AM +0000, Matthew Wilcox wrote:
>> On Tue, Feb 24, 2026 at 05:40:02PM -0800, Kees Cook wrote:
>> > +++ b/include/linux/slab.h
>> > @@ -1105,7 +1105,7 @@ static inline __alloc_size(1, 2) void *kmalloc_array_noprof(size_t n, size_t siz
>> >  	size_t bytes;
>> >  
>> >  	if (unlikely(check_mul_overflow(n, size, &bytes)))
>> > -		return NULL;
>> > +		bytes = SIZE_MAX;
>> >  	return kmalloc_noprof(bytes, flags);
>> 
>> Wouldn't this be better written as:
>> 
>> 	return kmalloc_noprof(size_mul(n, size), flags);
>> 
>> (etc)
> 
> Sure, I can convert them all that way if that's preferred?

Yeah I think it's better than effectively open-code the same thing?