Niels de Vos said: > On Mon, Apr 9, 2012 at 3:38 PM, Eric Paris <eparis at redhat.com> wrote: >> On Mon, 2012-04-09 at 00:31 +0200, Kevin Kofler wrote: >>> It also >>> breaks crash reporters such as DrKonqi (for DrKonqi, we work around this by >>> disabling the flag in kde-runtime's %post script, but there are other >>> similar debuggers in upstream software, some not packaged in Fedora) >> >> I ask in the bug how DrKonqi works on other distros with the YAMA >> security module enabled which implements a slightly different semantic >> and didn't hear a response. I have patches which I will try to get into >> the Fedora kernel later today that will allow us to seamlessly allow gdb >> to trace children. gdb -p would still require disabling the boolean. >> (Think about it a moment. gdb -p is the same as firefox trying to >> ptrace gnome-keyring) Eric and Dan, please don't reinvent the wheel here. >It seems that there is prctl() call to allow a specific PID (like gdb >stared by the signal-handler of DrKonqi) to trace the calling/crached >process. The idea comes from following the gdb discussion here: >- http://sourceware.org/ml/gdb-patches/2012-03/msg00274.html Please just use Yama -- it's already in the mainline kernel[1]. You don't need to create anything new. All the crash handlers and other tools (Firefox, Chrome, DrKonqi/KDE, and Wine) are already aware of how to declare ptrace relationships with prctl(PR_SET_PTRACER) from when I wrote Yama and sent patches to various upstreams. Just allowing child process relationships isn't sufficient, which is why PR_SET_PTRACER was created so that things like Wine could declare the entire cluster of wine-server-spawned processes as ptraceable, etc. Why go a totally new route when all of these problems were already solved? Please just read through the module documentation[2] and enable it[3], it'll make all of this just go away. You can even patch the ptrace manpage for PTRACE_ATTACH[4] so people know where to get more details. -Kees [1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=tree;f=security/yama;hb=HEAD [2] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/security/Yama.txt;hb=HEAD [3] http://git.kernel.org/?p=linux/kernel/git/kees/linux.git;a=commitdiff;h=25de2d649334d53ab168eb8178e0889a3533f3c1 [4] http://manpages.ubuntu.com/ptrace -- Kees Cook -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
