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>
This reverts commit 651e28c553.
This caused a regression:
"The specific problem is that dnsmasq refuses to start on openSUSE Leap
42.2. The specific cause is that and attempt to open a PF_LOCAL socket
gets EACCES. This means that networking doesn't function on a system
with a 4.14-rc2 system."
Sadly, the developers involved seemed to be in denial for several weeks
about this, delaying the revert. This has not been a good release for
the security subsystem, and this area needs to change development
practices.
Reported-and-bisected-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Tracked-by: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Seth Arnold <seth.arnold@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 8014370f12 ("apparmor: move path_link mediation to using labels")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This is a temporary step, towards using the file->ctx for delegation,
and also helps speed up file queries, until the permission lookup
cache is introduced.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Begin the actual switch to using domain labels by storing them on
the context and converting the label to a singular profile where
possible.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Instead of running file revalidation lazily when read/write are called
copy selinux and revalidate the file table on exec. This avoids
extra mediation overhead in read/write and also prevents file handles
being passed through to a grand child unchecked.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Dynamically allocating buffers is problematic and is an extra layer
that is a potntial point of failure and can slow down mediation.
Change path lookup to use the preallocated per cpu buffers.
Signed-off-by: John Johansen <john.johansen@canonical.com>
The aad macro can replace aad strings when it is not intended to. Switch
to a fn macro so it is only applied when intended.
Also at the same time cleanup audit_data initialization by putting
common boiler plate behind a macro, and dropping the gfp_t parameter
which will become useless.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Having ops be an integer that is an index into an op name table is
awkward and brittle. Every op change requires an edit for both the
op constant and a string in the table. Instead switch to using const
strings directly, eliminating the need for the table that needs to
be kept in sync.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Prepare to mark sensitive kernel structures for randomization by making
sure they're using designated initializers. These were identified during
allyesconfig builds of x86, arm, and arm64, with most initializer fixes
extracted from grsecurity.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
most of the ->d_inode uses there refer to the same inode IO would
go to, i.e. d_backing_inode()
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
It isn't needed. If you don't set the type of the data associated with
that type it is a pretty obvious programming bug. So why waste the cycles?
Signed-off-by: Eric Paris <eparis@redhat.com>
Linus found that the gigantic size of the common audit data caused a big
perf hit on something as simple as running stat() in a loop. This patch
requires LSMs to declare the LSM specific portion separately rather than
doing it in a union. Thus each LSM can be responsible for shrinking their
portion and don't have to pay a penalty just because other LSMs have a
bigger space requirement.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix failure in aa_change_onexec api when the request is made from a confined
task. This failure was caused by two problems
The AA_MAY_ONEXEC perm was not being mapped correctly for this case.
The executable name was being checked as second time instead of using the
requested onexec profile name, which may not be the same as the exec
profile name. This mistake can not be exploited to grant extra permission
because of the above flaw where the ONEXEC permission was not being mapped
so it will not be granted.
BugLink: http://bugs.launchpad.net/bugs/963756
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Move the path name lookup failure messages into the main path name lookup
routine, as the information is useful in more than just aa_path_perm.
Also rename aa_get_name to aa_path_name as it is not getting a reference
counted object with a corresponding put fn.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
The mapping of AA_MAY_META_READ for the allow mask was also being mapped
to the audit and quiet masks. This would result in some operations being
audited when the should not.
This flaw was hidden by the previous audit bug which would drop some
messages that where supposed to be audited.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
AppArmor does files enforcement via pathname matching. Matching is done
at file open using a dfa match engine. Permission is against the final
file object not parent directories, ie. the traversal of directories
as part of the file match is implicitly allowed. In the case of nonexistant
files (creation) permissions are checked against the target file not the
directory. eg. In case of creating the file /dir/new, permissions are
checked against the match /dir/new not against /dir/.
The permissions for matches are currently stored in the dfa accept table,
but this will change to allow for dfa reuse and also to allow for sharing
of wider accept states.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
