[PATCH] sysctl: fix the selinux_sysctl_get_sid

I goofed and when reenabling the fine grained selinux labels for
sysctls and forgot to add the "/sys" prefix before consulting
the policy database.  When computing the same path using
proc_dir_entries we got the "/sys" for free as it was part
of the tree, but it isn't true for clt_table trees.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 118ddfb614ee..b8ede1c7607b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1451,6 +1451,12 @@ static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
                 path = end;
                 table = table->parent;
         }
+        buflen -= 4;
+        if (buflen < 0)
+                goto out_free;
+        end -= 4;
+        memcpy(end, "/sys", 4);
+        path = end;
         rc = security_genfs_sid("proc", path, tclass, sid);
 out_free:
         free_page((unsigned long)buffer);