Re: [PATCH userspace 1/2] libselinux: fix invalid free in store_stem()/load_mmap()

[Petr Lautrbach <plautrba@redhat.com>]

Christian Göttsche <cgzones@googlemail.com> writes:

> Am Mi., 12. Mai 2021 um 12:25 Uhr schrieb Ondrej Mosnacek <omosnace@redhat.com>:
>>
>> Building libselinux with GCC 11.1.1 produces the following warning:
>> ```
>> In file included from label_file.c:24:
>> In function ‘store_stem’,
>>     inlined from ‘load_mmap’ at label_file.c:277:12,
>>     inlined from ‘process_file’ at label_file.c:551:5:
>> label_file.h:289:25: error: ‘free’ called on pointer ‘*mmap_area.next_addr’ with nonzero offset 4 [-Werror=free-nonheap-object]
>>   289 |                         free(buf);
>>       |                         ^~~~~~~~~
>> ```
>>
>> Indeed, in this case the pointer shouldn't be freed as it comes from
>> mmap. Fix this by adding a from_mmap parameter to store_stem() instead
>> of overriding the saved_data::from_mmap value in load_mmap().
>>
>> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
>
> See https://patchwork.kernel.org/project/selinux/patch/20210503175350.55954-17-cgzones@googlemail.com/
> for an alternative.

https://patchwork.kernel.org/project/selinux/patch/20210503175350.55954-17-cgzones@googlemail.com/ - Accepted

https://patchwork.kernel.org/project/selinux/patch/20210512102529.122753-2-omosnace@redhat.com/ - Rejected

Thanks to both!