According to the link in the article, the qsort() bug can only be triggered with a non-transitive cmp() function. Would such a cmp function ever be useful?
You don’t necessarily have to write a non-transitive cmp() function willingly, it may happen that you write one without realizing due to some edge cases where it’s not transitive.
"A qsort vulnerability is due to a missing bounds check and can lead to memory corruption. It has been present in all versions of glibc since 1992. "
This one amazes me. Imagine how many vulnerabilities future researchers will discover in ancient software that persisted/persist for decades.
C is just crazy. You accidentally forget to put the bounds in a sorting function, and now you are root.
According to the link in the article, the qsort() bug can only be triggered with a non-transitive cmp() function. Would such a cmp function ever be useful?
You don’t necessarily have to write a non-transitive cmp() function willingly, it may happen that you write one without realizing due to some edge cases where it’s not transitive.