Messages in this thread | | | From | Kees Cook <> | Date | Tue, 12 Jun 2018 15:52:19 -0700 | Subject | Re: REGRESSION?: debugfs: inode: debugfs_create_dir uses mode permission from parent |
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On Tue, Jun 12, 2018 at 3:40 PM, John Stultz <john.stultz@linaro.org> wrote: > Hey all, > I noticed recently that linus/master (plus patches) stopped booting > to UI on HiKey960, and I bisected the issue down to: > 92170b62f1c1 ("debugfs: inode: debugfs_create_dir uses mode permission > from parent") > > On the HiKey960 board, we mount debugfs via: > mount debugfs /sys/kernel/debug /sys/kernel/debug mode=755 > > But since the change, it seems most of the nodes in /sys/kernel/debug > are: drwx------ > > Which ends up breaking the egl library, keeping it from loading. > > This seems to be the expected behavior of the patch, but I'm surprised > the mode override is now ignored. It seems like the potential fix here > would be to set the /sys/kernel/debug dir to 755 prior to mounting? Or > is there some other advised solution?
This change has already be reverted from other people reporting the problem. Perhaps the root cause is the lack of propagation of the mode= value?
-Kees
-- Kees Cook Pixel Security
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