Predictable glusterfs log filename in world writable /tmp

[Ville Skyttä <ville.skytta@xxxxxxxxxxx>]

Hello!

I happened to stumble upon this:

$ grep /tmp engines/glusterfs.c
glfs_set_logging(fs, "/tmp/fio_gfapi.log", 7);

IIUC glfs starts appending to that file if it exists, which would mean
a vulnerability to arbitrary file append via a symlink. Briefly
discussed in private mail with Jens, agreed to send here for info.

Cheers, Ville