linux_dsm_epyc7002/security
Arnd Bergmann 7bba39ae52 apparmor: initialized returned struct aa_perms
gcc-4.4 points out suspicious code in compute_mnt_perms, where
the aa_perms structure is only partially initialized before getting
returned:

security/apparmor/mount.c: In function 'compute_mnt_perms':
security/apparmor/mount.c:227: error: 'perms.prompt' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.hide' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.cond' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.complain' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.stop' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.deny' is used uninitialized in this function

Returning or assigning partially initialized structures is a bit tricky,
in particular it is explicitly allowed in c99 to assign a partially
initialized structure to another, as long as only members are read that
have been initialized earlier. Looking at what various compilers do here,
the version that produced the warning copied uninitialized stack data,
while newer versions (and also clang) either set the other members to
zero or don't update the parts of the return buffer that are not modified
in the temporary structure, but they never warn about this.

In case of apparmor, it seems better to be a little safer and always
initialize the aa_perms structure. Most users already do that, this
changes the remaining ones, including the one instance that I got the
warning for.

Fixes: fa488437d0f9 ("apparmor: add mount mediation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-11-21 02:15:50 -08:00
..
apparmor apparmor: initialized returned struct aa_perms 2017-11-21 02:15:50 -08:00
integrity Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-07-05 11:26:35 -07:00
keys KEYS: load key flags and expiry time atomically in proc_keys_show() 2017-10-18 09:12:41 +01:00
loadpin security: mark LSM hooks as __ro_after_init 2017-03-06 11:00:15 +11:00
selinux selinux/stable-4.14 PR 20170831 2017-09-12 13:21:00 -07:00
smack lsm: fix smack_inode_removexattr and xattr_getsecurity memleak 2017-10-04 18:03:15 +11:00
tomoyo exec: Rename bprm->cred_prepared to called_set_creds 2017-08-01 12:02:48 -07:00
yama doc: ReSTify Yama.txt 2017-05-18 10:33:04 -06:00
commoncap.c commoncap: move assignment of fs_ns to avoid null pointer dereference 2017-10-19 13:09:33 +11:00
device_cgroup.c security/device_cgroup: Fix RCU_LOCKDEP_WARN() condition 2015-09-03 18:13:10 -07:00
inode.c securityfs: add the ability to support symlinks 2017-06-08 12:51:43 -07:00
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00
lsm_audit.c lsm_audit: update my email address 2017-08-17 15:33:39 -04:00
Makefile LSM: LoadPin for kernel file loading restrictions 2016-04-21 10:47:27 +10:00
min_addr.c mmap_min_addr check CAP_SYS_RAWIO only for write 2010-04-23 08:56:31 +10:00
security.c selinux/stable-4.14 PR 20170831 2017-09-12 13:21:00 -07:00