diff options
| author | Serge Hallyn <serge@hallyn.com> | 2008-02-29 15:14:57 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-03-20 09:46:36 -0700 |
| commit | aedb60a67c10a0861af179725d060765262ba0fb (patch) | |
| tree | 4a4a316f9f7d1ab0bf4da2cdd5c802bfb05c947f /security/smack | |
| parent | 457fb605834504af294916411be128a9b21fc3f6 (diff) | |
| download | linux-aedb60a67c10a0861af179725d060765262ba0fb.tar.gz | |
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')
| -rw-r--r-- | security/smack/smack_lsm.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 38d707593b31..732ba27923c4 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 |