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authorAndrew G. Morgan <morgan@kernel.org>2008-06-12 15:21:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-06-12 18:05:40 -0700
commit8cdbc2b9826b3543fecff2f6d6400fa77b21ffdd (patch)
treee42ddc9142988fffb2b4128e2d94b3913914dbe6
parent57d3c64fd8130ebdacd85a36c9656ba5e221f3a3 (diff)
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capabilities: add (back) dummy support for KEEPCAPS
The dummy module is used by folk that run security conscious code(!?). A feature of such code (for example, dhclient) is that it tries to operate with minimum privilege (dropping unneeded capabilities). While the dummy module doesn't restrict code execution based on capability state, the user code expects the kernel to appear to support it. This patch adds back faked support for the PR_SET_KEEPCAPS etc., calls - making the kernel behave as before 2.6.26. For details see: http://bugzilla.kernel.org/show_bug.cgi?id=10748 Signed-off-by: Andrew G. Morgan <morgan@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--security/dummy.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/security/dummy.c b/security/dummy.c
index f50c6c3c32c9..b8916883b77f 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -27,6 +27,8 @@
#include <linux/hugetlb.h>
#include <linux/ptrace.h>
#include <linux/file.h>
+#include <linux/prctl.h>
+#include <linux/securebits.h>
static int dummy_ptrace (struct task_struct *parent, struct task_struct *child)
{
@@ -607,7 +609,27 @@ static int dummy_task_kill (struct task_struct *p, struct siginfo *info,
static int dummy_task_prctl (int option, unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5, long *rc_p)
{
- return 0;
+ switch (option) {
+ case PR_CAPBSET_READ:
+ *rc_p = (cap_valid(arg2) ? 1 : -EINVAL);
+ break;
+ case PR_GET_KEEPCAPS:
+ *rc_p = issecure(SECURE_KEEP_CAPS);
+ break;
+ case PR_SET_KEEPCAPS:
+ if (arg2 > 1)
+ *rc_p = -EINVAL;
+ else if (arg2)
+ current->securebits |= issecure_mask(SECURE_KEEP_CAPS);
+ else
+ current->securebits &=
+ ~issecure_mask(SECURE_KEEP_CAPS);
+ break;
+ default:
+ return 0;
+ }
+
+ return 1;
}
static void dummy_task_reparent_to_init (struct task_struct *p)