Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1641091

Re: [PATCH] ipc/sem: Avoid indexing past end of sem_array

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

Hi Kees,

On 05/09/2017 12:23 AM, Kees Cook wrote:
> This changes the struct + trailing data pattern to using a void * so that
> the end of sem_array is found without possibly indexing past the end which
> can upset some static analyzers. Mostly, this ends up avoiding a cast
> between different non-void types, which the future randstruct GCC plugin
> was warning about.
Two question:
- Would the attached patch work with the randstruct plugin as well?
   If we touch the code, then I would propose that we remove sem_base 
entirely.

- ipc/util.h contains

 > #define ipc_rcu_to_struct(p)  ((void *)(p+1))

Does this trigger a warning with randstruct as well?
If we have to touch it, then I would remove it by merging struct 
kern_ipc_perm and struct ipc_rcu.

And, obviously:
Do you see any issues with the attached patch?
--
     Manfred

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH] ipc/sem: Avoid indexing past end of sem_array Manfred Spraul <manfred@colorfullife.com> - 2017-05-14 16:00 +0200
  Re: [PATCH] ipc/sem: Avoid indexing past end of sem_array Kees Cook <keescook@chromium.org> - 2017-05-15 19:50 +0200

csiph-web