1 files changed, 22 insertions, 15 deletions

diff --git a/fs/open.c b/fs/open.c
index a1450086e92f..a99ad09c3197 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -16,6 +16,7 @@
 #include <linux/namei.h>
 #include <linux/backing-dev.h>
 #include <linux/capability.h>
+#include <linux/securebits.h>
 #include <linux/security.h>
 #include <linux/mount.h>
 #include <linux/vfs.h>
@@ -425,7 +426,7 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
 {
         struct nameidata nd;
         int old_fsuid, old_fsgid;
-        kernel_cap_t old_cap;
+        kernel_cap_t uninitialized_var(old_cap);  /* !SECURE_NO_SETUID_FIXUP */
         int res;
 
         if (mode & ~S_IRWXO)    /* where's F_OK, X_OK, W_OK, R_OK? */
@@ -433,23 +434,27 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
 
         old_fsuid = current->fsuid;
         old_fsgid = current->fsgid;
-        old_cap = current->cap_effective;
 
         current->fsuid = current->uid;
         current->fsgid = current->gid;
 
-        /*
-         * Clear the capabilities if we switch to a non-root user
-         *
-         * FIXME: There is a race here against sys_capset.  The
-         * capabilities can change yet we will restore the old
-         * value below.  We should hold task_capabilities_lock,
-         * but we cannot because user_path_walk can sleep.
-         */
-        if (current->uid)
-                cap_clear(current->cap_effective);
-        else
-                current->cap_effective = current->cap_permitted;
+        if (!issecure(SECURE_NO_SETUID_FIXUP)) {
+                /*
+                 * Clear the capabilities if we switch to a non-root user
+                 */
+#ifndef CONFIG_SECURITY_FILE_CAPABILITIES
+                /*
+                 * FIXME: There is a race here against sys_capset.  The
+                 * capabilities can change yet we will restore the old
+                 * value below.  We should hold task_capabilities_lock,
+                 * but we cannot because user_path_walk can sleep.
+                 */
+#endif /* ndef CONFIG_SECURITY_FILE_CAPABILITIES */
+                if (current->uid)
+                        old_cap = cap_set_effective(__cap_empty_set);
+                else
+                        old_cap = cap_set_effective(current->cap_permitted);
+        }
 
         res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
         if (res)
@@ -478,7 +483,9 @@ out_path_release:
 out:
         current->fsuid = old_fsuid;
         current->fsgid = old_fsgid;
-        current->cap_effective = old_cap;
+
+        if (!issecure(SECURE_NO_SETUID_FIXUP))
+                cap_set_effective(old_cap);
 
         return res;
 }