SELinux: more GFP_NOFS fixups to prevent selinux from re-entering the fs code

More cases where SELinux must not re-enter the fs code. Called from the
d_instantiate security hook.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

security/selinux/hooks.c

@@ -1143,7 +1143,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 		}
 
 		len = INITCONTEXTLEN;
-		context = kmalloc(len, GFP_KERNEL);
+		context = kmalloc(len, GFP_NOFS);
 		if (!context) {
 			rc = -ENOMEM;
 			dput(dentry);
@@ -1161,7 +1161,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			}
 			kfree(context);
 			len = rc;
-			context = kmalloc(len, GFP_KERNEL);
+			context = kmalloc(len, GFP_NOFS);
 			if (!context) {
 				rc = -ENOMEM;
 				dput(dentry);
@@ -1185,7 +1185,8 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			rc = 0;
 		} else {
 			rc = security_context_to_sid_default(context, rc, &sid,
-			                                     sbsec->def_sid);
+							     sbsec->def_sid,
+							     GFP_NOFS);
 			if (rc) {
 				printk(KERN_WARNING "%s:  context_to_sid(%s) "
 				       "returned %d for dev=%s ino=%ld\n",

security/selinux/include/security.h

@@ -86,7 +86,8 @@ int security_sid_to_context(u32 sid, char **scontext,
 int security_context_to_sid(char *scontext, u32 scontext_len,
 	u32 *out_sid);
 
-int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *out_sid, u32 def_sid);
+int security_context_to_sid_default(char *scontext, u32 scontext_len,
+				    u32 *out_sid, u32 def_sid, gfp_t gfp_flags);
 
 int security_get_user_sids(u32 callsid, char *username,
 			   u32 **sids, u32 *nel);

security/selinux/ss/services.c

@@ -680,7 +680,8 @@ int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
 
 }
 
-static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
+static int security_context_to_sid_core(char *scontext, u32 scontext_len,
+					u32 *sid, u32 def_sid, gfp_t gfp_flags)
 {
 	char *scontext2;
 	struct context context;
@@ -709,7 +710,7 @@ static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *s
 	   null suffix to the copy to avoid problems with the existing
 	   attr package, which doesn't view the null terminator as part
 	   of the attribute value. */
-	scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
+	scontext2 = kmalloc(scontext_len+1, gfp_flags);
 	if (!scontext2) {
 		rc = -ENOMEM;
 		goto out;
@@ -809,7 +810,7 @@ static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *s
 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
 {
 	return security_context_to_sid_core(scontext, scontext_len,
-	                                    sid, SECSID_NULL);
+					    sid, SECSID_NULL, GFP_KERNEL);
 }
 
 /**
@@ -829,10 +830,11 @@ int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
  * memory is available, or 0 on success.
  */
-int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
+int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid,
+				    u32 def_sid, gfp_t gfp_flags)
 {
 	return security_context_to_sid_core(scontext, scontext_len,
-	                                    sid, def_sid);
+					    sid, def_sid, gfp_flags);
 }
 
 static int compute_sid_handle_invalid_context(