On Fri, 17 Oct 2014 06:30:29 +0900 Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> wrote:
> Regarding UMH_NO_WAIT, the sub_info structure can be freed by > __call_usermodehelper() before the worker thread returns from > do_execve(), allowing memory corruption when do_execve() failed > after exec_mmap() is called. > > Regarding UMH_WAIT_EXEC, the call to umh_complete() allows > call_usermodehelper_exec() to continue which then frees sub_info. > > To fix this race, we need to make sure that the call to > call_usermodehelper_freeinfo() in call_usermodehelper_exec() is > always made after the last store to sub_info->retval. I like this improved description for the UMH_NO_WAIT and UMH_WAIT_EXEC cases. I mix it with parts of the original description. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
