OSS-Fuzz issue 42877

[Mark Wielaard]

Hi Evgeny,

On Fri, Dec 24, 2021 at 12:49:53AM +0300, Evgeny Vereshchagin wrote:
> All those issues can be reproduced by downloading public testcases and
> passing them to ./fuzz/dwfl-core. That particular issue can be reproduced with
> ```
> autoreconf -i -f
> ./configure --enable-maintainer-mode --enable-sanitize-address --enable-sanitize-undefined
> make -j$(nproc) V=1
> make -C tests fuzz-dwfl-core
> 
> wget -O CRASH https://oss-fuzz.com/download?testcase_id=4756614962348032
> 
> LD_LIBRARY_PATH="./libdw;./libelf" ./tests/fuzz-dwfl-core ./CRASH
> Running: ./CRASH
> =================================================================
> ==266852==ERROR: AddressSanitizer: unknown-crash on address 0x7f492ff9c000 at pc 0x7f4934340b00 bp 0x7ffc09558f30 sp 0x7ffc095586e0
> READ of size 64 at 0x7f492ff9c000 thread T0
>     #0 0x7f4934340aff in __interceptor_memcpy (/lib64/libasan.so.6+0x39aff)
>     #1 0x7f4933f2aa90 in memcpy /usr/include/bits/string_fortified.h:29
>     #2 0x7f4933f2aa90 in dwfl_segment_report_module /home/vagrant/elfutils/libdwfl/dwfl_segment_report_module.c:385

Thanks that is useful. I think this issue has the same root cause as
an issue found by afl-fuzz for which I posted a patch here:
https://sourceware.org/pipermail/elfutils-devel/2021q4/004597.html

Cheers,

Mark