Bug#883407: libc6: getpwnam_r() leaks memory

[Aurelien Jarno <aurelien@aurel32.net>]

On 2017-12-03 17:34, Tim Rühsen wrote:
> Package: libc6
> Version: 2.25-3
> Severity: normal
> 
> Dear Maintainer,
> 
> valgrinding a C code shows the following:
> 
> ==27943== 4,096 bytes in 1 blocks are definitely lost in loss record 3 of 3
> ==27943==    by 0x6C27715: getpwnam_r@@GLIBC_2.2.5 (getXXbyYY_r.c:314)
> ==27943==    by 0x4E8569F: rpl_glob (glob.c:781)
> 
> That rpl_glob() is gnulib's glob replacement. The code there looks good.
> And valgrind doesn't/didn't show this leak with previous (2.24 and lower)
> versions of glibc.
> 
> I can't currently provide you with a short reproducer (out of time here).

It's not something I can reproduce here, but getpwnam_r can behave very
differently depending on the nss configuration your system. A small
reproducer and the content of /etc/nsswitch.conf would definitely help.

That said libc6 version 2.25-3 included security fixes and memory leak
fixes for the glob function. Can you confirm the version you used, and
if it's really 2.25-3 try with version 2.25-2 which is still in testing.

Thanks,
Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net