path: root/security/smack
diff options
authorSerge Hallyn <serge@hallyn.com>2008-02-29 15:14:57 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2008-03-20 09:46:36 -0700
commitaedb60a67c10a0861af179725d060765262ba0fb (patch)
tree4a4a316f9f7d1ab0bf4da2cdd5c802bfb05c947f /security/smack
parent457fb605834504af294916411be128a9b21fc3f6 (diff)
file capabilities: remove cap_task_kill()
The original justification for cap_task_kill() was as follows: check_kill_permission() does appropriate uid equivalence checks. However with file capabilities it becomes possible for an unprivileged user to execute a file with file capabilities resulting in a more privileged task with the same uid. However now that cap_task_kill() always returns 0 (permission granted) when p->uid==current->uid, the whole hook is worthless, and only likely to create more subtle problems in the corner cases where it might still be called but return -EPERM. Those cases are basically when uids are different but euid/suid is equivalent as per the check in check_kill_permission(). One example of a still-broken application is 'at' for non-root users. This patch removes cap_task_kill(). Signed-off-by: Serge Hallyn <serge@hallyn.com> Acked-by: Andrew G. Morgan <morgan@kernel.org> Earlier-version-tested-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security/smack')
1 files changed, 0 insertions, 5 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 38d707593b3..732ba27923c 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1117,11 +1117,6 @@ static int smack_task_movememory(struct task_struct *p)
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
int sig, u32 secid)
- int rc;
- rc = cap_task_kill(p, info, sig, secid);
- if (rc != 0)
- return rc;
* Special cases where signals really ought to go through
* in spite of policy. Stephen Smalley suggests it may