mmapfail

Bash script to detect bad checks of mmap() return value

what?

The mmap() POSIX function returns MAP_FAILED or -1 when an error occurs. A common mistake is to check the return value for 0 instead. This script tries to heuristically find such bugs in an automated way.

findings

• efivar: rhboot/efivar#152
• GNOME/gvfs: https://gitlab.gnome.org/GNOME/gvfs/-/issues/477
• Geeqie: BestImageViewer/geeqie#771
• ZoneDetect: BertoldVdb/ZoneDetect#26
• GDB: https://sourceware.org/bugzilla/show_bug.cgi?id=26016
• GNOME/gdk-pixbuf: https://gitlab.gnome.org/GNOME/gdk-pixbuf/-/issues/158
• KDE/kwayland: https://bugs.kde.org/show_bug.cgi?id=421868
• Mesa: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5150
• QEMU: https://bugs.launchpad.net/qemu/+bug/1879998
• GNOME/Tracker: https://gitlab.gnome.org/GNOME/tracker-miners/-/merge_requests/201

Article (in German):

• Golem.de: mmap - Codeanalyse mit sechs Zeilen Bash