freebsd-nq/tests/sys/Makefile
John Baldwin 8ce99bb405 Properly do a deep copy of the ioctls capability array for fget_cap().
fget_cap() tries to do a cheaper snapshot of a file descriptor without
holding the file descriptor lock.  This snapshot does not do a deep
copy of the ioctls capability array, but instead uses a different
return value to inform the caller to retry the copy with the lock
held.  However, filecaps_copy() was returning 1 to indicate that a
retry was required, and fget_cap() was checking for 0 (actually
'!filecaps_copy()').  As a result, fget_cap() did not do a deep copy
of the ioctls array and just reused the original pointer.  This cause
multiple file descriptor entries to think they owned the same pointer
and eventually resulted in duplicate frees.

The only code path that I'm aware of that triggers this is to create a
listen socket that has a restricted list of ioctls and then call
accept() which calls fget_cap() with a valid filecaps structure from
getsock_cap().

To fix, change the return value of filecaps_copy() to return true if
it succeeds in copying the caps and false if it fails because the lock
is required.  I find this more intuitive than fixing the caller in
this case.  While here, change the return type from 'int' to 'bool'.

Finally, make filecaps_copy() more robust in the failure case by not
copying any of the source filecaps structure over.  This avoids the
possibility of leaking a pointer into a structure if a similar future
caller doesn't properly handle the return value from filecaps_copy()
at the expense of one more branch.

I also added a test case that panics before this change and now passes.

Reviewed by:	kib
Discussed with:	mjg (not a fan of the extra branch)
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D15047
2018-04-17 18:07:40 +00:00

36 lines
666 B
Makefile

# $FreeBSD$
.include <src.opts.mk>
TESTSDIR= ${TESTSBASE}/sys
TESTS_SUBDIRS+= acl
TESTS_SUBDIRS+= aio
TESTS_SUBDIRS+= capsicum
TESTS_SUBDIRS+= ${_cddl}
TESTS_SUBDIRS+= fifo
TESTS_SUBDIRS+= file
TESTS_SUBDIRS+= fs
TESTS_SUBDIRS+= geom
TESTS_SUBDIRS+= kern
TESTS_SUBDIRS+= kqueue
TESTS_SUBDIRS+= mac
TESTS_SUBDIRS+= mqueue
TESTS_SUBDIRS+= netinet
TESTS_SUBDIRS+= netipsec
TESTS_SUBDIRS+= netpfil
TESTS_SUBDIRS+= opencrypto
TESTS_SUBDIRS+= posixshm
TESTS_SUBDIRS+= sys
TESTS_SUBDIRS+= vfs
TESTS_SUBDIRS+= vm
.if ${MK_CDDL} != "no"
_cddl= cddl
.endif
# Items not integrated into kyua runs by default
SUBDIR+= pjdfstest
.include <bsd.test.mk>