Hi Helge!
* Helge Kreutzmann <deb...@helgefjell.de>, 2019-03-23, 20:48:
+ /* Create a secure private temporary directory */
+ fifosdir = mkdtemp(FIFODIR "tvtimeXXXXXX");
The mkdtemp(2) man page says: "Since it will be modified, template must
not be a string constant, but should be declared as a character array."
This is the reason it segfaults.
Also, slash is missing between FIFODIR and "tvtime".
You would need something like this:
char *fifosdir;
char fifosdir_buf[] = FIFODIR "/tvtimeXXXXXX";
fifosdir = mkdtemp(fifosdir_buf);
So (with the addition of error handling) this would fix insecure use of
/tmp; but it also breaks communication between tvtime-command(1) and
tvtime(1). They need to use the same fifo to communicate, but mkdtemp()
ensures that this is never the case:
$ tvtime-command QUIT
Reading configuration from /etc/tvtime/tvtime.xml
Reading configuration from /home/jwilk/.tvtime/tvtime.xml
tvtime-command: Cannot open /tmp/tvtimeHH48wA/.TV-jwilk/tvtimefifo-borsuk: No
such file or directory
It would be best to avoid using /tmp for fifos. tvtime already falls
back to $HOME when /tmp couldn't be used (grep for "put the fifo in
$HOME" in src/utils.c), to this should be a matter of disabling the /tmp
codepath.
--
Jakub Wilk
