[PATCH] Improve DST handling (Bug 23102, Bug 21942, Bug 18018, Bug, 23259, CVE-2011-0536 ).

[Carlos O'Donell]

On 06/06/2018 10:15 AM, Florian Weimer wrote:
> On 06/06/2018 07:02 AM, Carlos O'Donell wrote:
>> +/* Passed the start of a DST sequence at the first '$' occurrence.
>> +Â Â  See the DL_DST_COUNT macro which inlines the strchr to find the
>> +Â Â  first occurrence of '$' and optimizes that likely case that there
>> +   is no DST.  If there is a DST we call into _dl_dst_count to count
>> +   the number of DSTs.  We count all known DSTs regardless of
>> +Â Â  __libc_enable_secure; the caller is responsible for enforcing
>> +Â Â  the security of the substitution rules (usually
>> +   _dl_dst_substitute).  */
> 
> Maybe kill DL_DST_COUNT?  It doesn't look useful to me.

Killed.

>> +      /* All DSTs must follow ELF gABI rules, see is_dst ().  */
>> +Â Â Â Â Â  if ((len = is_dst (name, "ORIGIN")) != 0
>> +Â Â Â Â Â  || (len = is_dst (name, "PLATFORM")) != 0
>> +Â Â Â Â Â  || (len = is_dst (name, "LIB")) != 0)
>> Â Â Â Â Â  ++cnt;
> 
> len is never read, so you can remove the variable.

Removed.

v2 patch coming up.

Cheers,
Carlos