On Fri, 2017-08-04 at 23:20 +0200, Yury V. Zaytsev wrote: > The most obvious reason for the segfault would have been that somebody has > freed `view->filename_vpath` without setting it to NULL, but a quick grep > for `->filename_vpath` doesn't reveal anything suspicious :-(
Discussion on IRC made us think that it was using memory that has been allocated but not initialised, because the MALLOC_PERTURB_=254 MALLOC_CHECK_=2 combination causes glibc to poison new memory allocations with 0xFE and if you then see 0xFE anywhere, that means that the program is buggy and interacting with uninitialised memory. https://www.gnu.org/software/libc/manual/html_node/Heap-Consistency-Checking.html http://udrepper.livejournal.com/11429.html > So this makes me think that maybe something else corrupted the memory > indirectly, but then I can't see how this can be reasonably investigated > without a sanitizer like report or even better a reproducer... The issue is easily reproducible for me and I think you could reproduce it by introducing a 5 second sleep call just before the panel setup. PS: you might be interested in the valgrind output for one of the sessions where I was able to press Ctrl+x q early enough. The log clearly shows that valgrind found a number of invalid reads. https://people.debian.org/~pabs/tmp/valgrind-mc.gz PS: I would suggest running the mc code through some static analysis tools, either via check-all-the-things or by manually running the tools listed in these two configuration files: https://anonscm.debian.org/cgit/collab-maint/check-all-the-things.git/tree/data/c.ini https://anonscm.debian.org/cgit/collab-maint/check-all-the-things.git/tree/data/elf.ini If you are fine with using proprietary services to improve free code, you could look at Coverity. You could also get Google to do some fuzzing of the mc codebase. https://scan.coverity.com/ https://www.linux.com/blog/2017/7/googles-oss-fuzz-tool-helps-secure-open-source-projects -- bye, pabs https://wiki.debian.org/PaulWise
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