SELinux: better printk when file with invalid label found

Currently when an inode is read into the kernel with an invalid label string (can often happen with removable media) we output a string like: SELinux: inode_doinit_with_dentry: context_to_sid([SOME INVALID LABEL]) returned -22 dor dev=[blah] ino=[blah] Which is all but incomprehensible to all but a couple of us. Instead, on EINVAL only, I plan to output a much more user friendly string and I plan to ratelimit the printk since many of these could be generated very rapidly. Signed-off-by: Eric Paris <[email protected]> Acked-by: Stephen Smalley <[email protected]> Signed-off-by: James Morris <[email protected]>
ambv · Feb 13, 2009 · 4ba0a8a · 4ba0a8a
1 parent 200ac53
commit 4ba0a8a
Showing 1 changed file with 13 additions and 4 deletions.
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
@@ -1315,10 +1315,19 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 							     sbsec->def_sid,
 							     GFP_NOFS);
 			if (rc) {
-				printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
-				       "returned %d for dev=%s ino=%ld\n",
-				       __func__, context, -rc,
-				       inode->i_sb->s_id, inode->i_ino);
+				char *dev = inode->i_sb->s_id;
+				unsigned long ino = inode->i_ino;
+
+				if (rc == -EINVAL) {
+					if (printk_ratelimit())
+						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
+							"context=%s.  This indicates you may need to relabel the inode or the "
+							"filesystem in question.\n", ino, dev, context);
+				} else {
+					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
+					       "returned %d for dev=%s ino=%ld\n",
+					       __func__, context, -rc, dev, ino);
+				}
 				kfree(context);
 				/* Leave with the unlabeled SID */
 				rc = 0;