On Wed, Sep 10, 2014 at 3:00 AM, Andrey Chernov <a...@freebsd.org> wrote:
> On 09.09.2014 21:53, Patrick Kelsey wrote: > > I don't think it is worth the trouble, as given the larger pattern of > > libc routines requiring multiple capsicum rights, it seems one will in > > general have to have libc implementation knowledge when using it in > > concert with capsicum. For example, consider the limitfd() routine in > > kdump.c, which provides rights for the TIOCGETA ioctl to be used on > > stdout so the eventual call to isatty() via printf() will work as > intended. > > > > I think the above kdump example is a good one for the subtle issues that > > can arise when using capsicum with libc. That call to isatty() is via a > > widely-used internal libc routine __smakebuf(). __smakebuf() also calls > > __swhatbuf(), which in turn calls _fstat(), all to make sure that output > > to a tty is line buffered by default. It would appear that programs > > that restrict rights on stdout without allowing CAP_IOCTL and CAP_FSTAT > > could be disabling the normally default line buffering when stdout is a > > tty. kdump goes the distance, but dhclient does not (restricting stdout > > to CAP_WRITE only). > > > > In any event, the patch attached to my first message is seeming like the > > way to go. > > Well, then commit it (if capsicum team agrees). > > > Will do - thanks for the feedback. -Patrick _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
