|Summary:||libsemanage calls mkdir() without setting the umask properly|
|Product:||Red Hat Enterprise Linux 7||Reporter:||Jakub Hrozek <jhrozek>|
|Component:||libsemanage||Assignee:||Vit Mojzis <vmojzis>|
|Status:||CLOSED ERRATA||QA Contact:||Jan Zarsky <jzarsky>|
|Version:||7.1||CC:||awilliam, dapospis, dpal, dwalsh, jzarsky, ksrot, lvrabec, mgrepl, mmalik, plautrba, pvrabec, ssekidde|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|:||1371389 (view as bug list)||Environment:|
|Last Closed:||2018-10-30 09:35:42 UTC||Type:||Bug|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
Description Jakub Hrozek 2015-01-27 16:16:06 UTC
Description of problem: On some places, like semanage_copy_dir(), libsemanage creates a directory with certain permissions using mkdir(path, 0700) and relies on the permissions being correct. But it never sets or checks the umask, so programs using libsemanage with a very restrictive umask (like deamons) might end up creating the directory with wrong permissions. Version-Release number of selected component (if applicable): How reproducible: always Steps to Reproduce: 1. set a restrictive umask 2. call libsemanage functions 3. ls -ld /etc/selinux/targeted/modules/active Actual results: clobbered permissions Expected results: permissions are as libsemanage expects them. Additional info:
Comment 2 Roland Mainz 2015-01-27 16:39:56 UTC
Basically libsemanage should fix the permissions after the |mkdir()| call like the mkdir(1) code in https://searchcode.com/codesearch/view/5481405/ line 160 does. An even better way would be to use |mkdirat()| and |fchmodat()| to prevent attacks which swap the parent directory, e.g. you |dirfd = open(parentdirname, O_SEARCH)| and then do |mkdirat(dirfd, ...| and |fchmodat(dirfd, ...)|. Note that Linux does not have POSIX |O_SEARCH| but aliasing it to |O_PATH| works fine, e.g. do this ... -- snip -- #ifndef O_SEARCH #define O_SEARCH (O_PATH) #endif -- snip -- ... and you're done...
Comment 4 Petr Lautrbach 2015-07-21 14:49:59 UTC
It needs to be fixed and discussed upstream first. When an user sets umask, she could have a reason for that. I,m postponing this bug to 7.3. Sorry.
Comment 7 Jan Zarsky 2016-08-30 06:49:35 UTC
Described reproducer causes clobbered permissions on RHEL-7.2 and older, on RHEL-7.3 with libsemanage-2.5-3.el7.x86_64 it passes, the permissions stays the same. So this bug is fixed for RHEL-7.3. (There is clone of this bug for RHEL6: https://bugzilla.redhat.com/show_bug.cgi?id=1371389 )
Comment 16 errata-xmlrpc 2018-10-30 09:35:42 UTC
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2018:3088
Comment 17 Adam Williamson 2018-12-18 01:39:07 UTC
See also (RIP the 'See also' field, apparently a casualty of the Bugzilla 5 migration :<): https://bugzilla.redhat.com/show_bug.cgi?id=1654537 and https://bugzilla.redhat.com/show_bug.cgi?id=1644919 . Now this has been fixed, perhaps this chunk of sssd: https://pagure.io/SSSD/sssd/blob/945865a/f/src/providers/ipa/selinux_child.c#_144 may not be needed any more? It has caused us some issues lately.