[PATCH] selinux: tracer SID fix

Fix SELinux to not reset the tracer SID when the child is already being
traced, since selinux_ptrace is also called by proc for access checking
outside of the context of a ptrace attach.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index b7773bf..b65c201 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1262,7 +1262,7 @@ static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
 
        rc = task_has_perm(parent, child, PROCESS__PTRACE);
        /* Save the SID of the tracing process for later use in apply_creds. */
-       if (!rc)
+       if (!(child->ptrace & PT_PTRACED) && !rc)
                csec->ptrace_sid = psec->sid;
        return rc;
 }