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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/capability.c
parent457fb605834504af294916411be128a9b21fc3f6 (diff)
downloadlinux-linaro-stable-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/capability.c')
-rw-r--r--security/capability.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/security/capability.c b/security/capability.c
index 9e99f36a8b5c..2c6e06d18fab 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -40,7 +40,6 @@ static struct security_operations capability_ops = {
.inode_need_killpriv = cap_inode_need_killpriv,
.inode_killpriv = cap_inode_killpriv,
- .task_kill = cap_task_kill,
.task_setscheduler = cap_task_setscheduler,
.task_setioprio = cap_task_setioprio,
.task_setnice = cap_task_setnice,