Re: [yocto-patches] [pseudo] [PATCH 6/7] exec*: Replace bash workaround to avoid memory corruption

Hello Richard,

On Wed Jul 1, 2026 at 3:13 PM CEST, Richard Purdie via lists.yoctoproject.org wrote:
> Bash intercepts getenv/setenv/unsetenv and does magic with it internally.
>
> The data pointed to by environ may not be allocated by glibc but by bash
> and the glibc env functions have their own memory handling outside of malloc.
> Unfortuantely bash doesn't keep environ and the result of setenv/getenv/unsetenv
> in sync either. This means the current workaround badly corrupts memory and it
> is just luck we're not breaking more often than the occasional opkg-build segfaults
> we've been seeing.
>
> Fixing this is tricky, the best we can probably do is to read through environ and
> create our own copy of the it, modifying it how we need to keep the pseudo variables
> correct.
>
> We do already have a function which can copyn and modify the environment, we can

s,copyn,copy,

> therefore swap some setupenv calls for setupenvp and switch out environ around
> the exec calls.
>
> Signed-off-by: Richard Purdie <[email protected]>
> ---
>  ports/common/guts/execv.c  | 19 ++++++++++++++-----
>  ports/common/guts/execvp.c | 15 ++++++++++++---
>  ports/unix/guts/popen.c    | 16 +++++++++++++---
>  ports/unix/guts/system.c   | 16 +++++++++++++---

Don't you need to make these changes to execve(), and posix_spawn{,p}()?
i.e. in files:
 - ports/common/guts/posix_spawnp.c
 - ports/common/guts/posix_spawn.c
 - ports/common/guts/execve.c

Regards,
Gaël