On 2024-04-06, Страхиња Радић <cont...@strahinja.org> wrote: > Дана 24/04/06 06:04PM, Stuart Henderson написа: >> The fact that these all started hitting this with the same printf string >> (including tmux, which is in base) makes me wonder if it's coming from a >> library, the most likely being libcurses which was updated between 7.4 >> and 7.5 (which all of those use). >> >> Try to ascertain what's going on when that message is logged. ktrace >> might give some clues. > > Of course, the package containing the code passing NULL to *printf should be > identified first, and the bug report should be sent to that package. It is > entirely possible that it is libcurses or another library. In the case of > dunst, it was dunst.
libcurses and tmux are not packages, they are in the base OS. > Passing NULL to *printf is Undefined Behavior in C, and there is a > StackOverflow answer detailing the reasons at [1]. > > [1]: https://stackoverflow.com/a/11589500 Yes. It's very common though, especially when constructing strings for debug logging. I see this a lot with software in the GNOME ecosystem using sprintf for this. That's interesting about the compiler optimisation for printf->puts, though I think it won't be used in many cases where the pointer nay be null so many uses of this won't trigger crashes for that reason. -- Please keep replies on the mailing list.
