[v1,2/2] seccomp: Set PF_SUPERPRIV when checking capability
diff mbox series

Message ID 20201030123849.770769-3-mic@digikod.net
State New, archived
Headers show
Series
  • Fix misuse of security_capable()
Related show

Commit Message

Mickaël Salaün Oct. 30, 2020, 12:38 p.m. UTC
From: Mickaël Salaün <mic@linux.microsoft.com>

Replace the use of security_capable(current_cred(), ...) with
ns_capable_noaudit() which set PF_SUPERPRIV.

Since commit 98f368e9e263 ("kernel: Add noaudit variant of
ns_capable()"), a new ns_capable_noaudit() helper is available.  Let's
use it!

Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Will Drewry <wad@chromium.org>
Cc: stable@vger.kernel.org
Fixes: e2cfabdfd075 ("seccomp: add system call filtering using BPF")
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
---
 kernel/seccomp.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Jann Horn Oct. 30, 2020, 3:34 p.m. UTC | #1
On Fri, Oct 30, 2020 at 1:39 PM Mickaël Salaün <mic@digikod.net> wrote:
> Replace the use of security_capable(current_cred(), ...) with
> ns_capable_noaudit() which set PF_SUPERPRIV.
>
> Since commit 98f368e9e263 ("kernel: Add noaudit variant of
> ns_capable()"), a new ns_capable_noaudit() helper is available.  Let's
> use it!
>
> Cc: Jann Horn <jannh@google.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
> Cc: Will Drewry <wad@chromium.org>
> Cc: stable@vger.kernel.org
> Fixes: e2cfabdfd075 ("seccomp: add system call filtering using BPF")
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>

Reviewed-by: Jann Horn <jannh@google.com>

Patch
diff mbox series

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 8ad7a293255a..53a7d1512dd7 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -38,7 +38,7 @@ 
 #include <linux/filter.h>
 #include <linux/pid.h>
 #include <linux/ptrace.h>
-#include <linux/security.h>
+#include <linux/capability.h>
 #include <linux/tracehook.h>
 #include <linux/uaccess.h>
 #include <linux/anon_inodes.h>
@@ -558,8 +558,7 @@  static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
 	 * behavior of privileged children.
 	 */
 	if (!task_no_new_privs(current) &&
-	    security_capable(current_cred(), current_user_ns(),
-				     CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) != 0)
+			!ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN))
 		return ERR_PTR(-EACCES);
 
 	/* Allocate a new seccomp_filter */