Re: [PATCH] mm: Handle ksize() vs __alloc_size by forgetting size

[Andrew Morton]

On Fri, 25 Feb 2022 14:16:25 -0800 Kees Cook <keescook@xxxxxxxxxxxx> wrote:

> If ksize() is used on an allocation, the compiler cannot make any
> assumptions about its size any more (as hinted by __alloc_size). Force
> it to forget.
> 
> One caller was using a container_of() construction that needed to be
> worked around.

Please, when fixing something do fully explain what that thing is.  I,
for one, simply cannot understand why this change is being proposed.

Especially when proposing a -stable backport!  Tell readers what was
the end-user impact of the bug.

> Link: https://github.com/ClangBuiltLinux/linux/issues/1599

Even that didn't tell me.  Is it just a clang warning?  Does the kernel
post your private keys on reddit then scribble all over your disk
drive?  I dunno.