[GIT] Apparmor bugfix

From: James Morris
Date: Tue Mar 27 2012 - 10:14:01 EST


Hi Linus,

Please pull this fix for Apparmor.

The following changes since commit e22057c8599373e5caef0bc42bdb95d2a361ab0d:
Linus Torvalds (1):
Merge tag 'stable/for-linus-3.4-tag-two' of git://git.kernel.org/.../konrad/xen

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git for-linus

John Johansen (1):
apparmor: Fix change_onexec when called from a confined task

security/apparmor/domain.c | 3 ++-
security/apparmor/file.c | 2 ++
2 files changed, 4 insertions(+), 1 deletions(-)

commit 0421ea91ddc7895a5a68d3bc670ed4b8e6448a42
Author: John Johansen <john.johansen@xxxxxxxxxxxxx>
Date: Tue Mar 27 04:14:33 2012 -0700

apparmor: Fix change_onexec when called from a confined task

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@xxxxxxxxxxxxx>
Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx>

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 7c69599..6327685 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -410,7 +410,8 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
* exec\0change_profile
*/
state = aa_dfa_null_transition(profile->file.dfa, state);
- cp = change_profile_perms(profile, cxt->onexec->ns, name,
+ cp = change_profile_perms(profile, cxt->onexec->ns,
+ cxt->onexec->base.name,
AA_MAY_ONEXEC, state);

if (!(cp.allow & AA_MAY_ONEXEC))
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index 3022c0f..5d176f2 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -215,6 +215,8 @@ static struct file_perms compute_perms(struct aa_dfa *dfa, unsigned int state,
/* change_profile wasn't determined by ownership in old mapping */
if (ACCEPT_TABLE(dfa)[state] & 0x80000000)
perms.allow |= AA_MAY_CHANGE_PROFILE;
+ if (ACCEPT_TABLE(dfa)[state] & 0x40000000)
+ perms.allow |= AA_MAY_ONEXEC;

return perms;
}
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