Re: [PATCH] multipathd: Don't look at pointer to removed path

[Benjamin Marzinski <bmarzins@redhat.com>]

On Thu, Oct 29, 2026 at 07:50:14PM -0400, Benjamin Marzinski wrote:
> In uev_update_path(), if the path wwid changes, we remove it and use
> needs_reinit to re-add the path. Once we remove the path, pp is pointing to
> freed memory, but we still read the value it pp to see if it's NULL before we
> check needs_reinit. This doesn't cause any bugs, since we don't dereference it,
> but it would still be cleaner if we stopped accessing it completely after we
> freed it. This is easy to do, since we only ever set needs_reinit if pp is
> non-NULL. So just check needs_reinit before we check if pp is NULL.
> 
> Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

Since this is just a cosmetic change, I'll wait till Brian's
WWID verifying patch lands, and rebase on top of that.

-Ben

> ---
>  multipathd/main.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/multipathd/main.c b/multipathd/main.c
> index 9bce4d6b..792bee36 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -1769,6 +1769,9 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
>  	}
>  out:
>  	lock_cleanup_pop(vecs->lock);
> +	/* pp->initialized must not be INIT_PARTIAL if needs_reinit is set */
> +	if (needs_reinit)
> +		return uev_add_path(uev, vecs, 1);
>  	if (!pp) {
>  		/* If the path is blacklisted, print a debug/non-default verbosity message. */
>  		if (uev->udev) {
> @@ -1787,9 +1790,6 @@ out:
>  
>  		condlog(0, "%s: spurious uevent, path not found", uev->kernel);
>  	}
> -	/* pp->initialized must not be INIT_PARTIAL if needs_reinit is set */
> -	if (needs_reinit)
> -		retval = uev_add_path(uev, vecs, 1);
>  	return retval;
>  }
>  
> -- 
> 2.56.0
>