Re: [PATCH] staging: greybus: don't use index pointer after iter

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jul 07, 2022 at 03:59:54PM +0530, Karthik Alapati wrote:
> There are some usages of index pointer of list(w) which may not point to
> the right entry when the required entry is not found and the list traversal
> completes with index pointer pointing to the last entry. So, use w_found
> flag to track the case where the entry is found.
> 
> Currently, When the condition (w->dapm != dapm) is true the loop continues
> and when it is not then it compares the name strings and breaks out of the
> loop if they match with w pointing to the right entry and it also breaks
> out of loop if they didn't match by additionally setting w to NULL. But
> what if the condition (w->dapm != dapm) is never false and the list
> traversal completes with w pointing to last entry then usage of it after
> the iter may not be correct. And there is no way to know whether the entry
> is found. So, if we introduce w_found to track when the entry is found
> then we can account for the case where the entry is not actually found and
> the list traversal completes.
> 
> Fixes coccinelle error:
> drivers/staging/greybus/audio_helper.c:135:7-8: ERROR:
> invalid reference to the index variable of the iterator on line 127
> 
> Signed-off-by: Karthik Alapati <mail@karthek.com>

Also, always at the very least, test-build your patches to ensure that
they pass that step.  This patch fails to build :(

greg k-h