X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=lib%2Fvsprintf.c;h=ae02e421b75fa4648091114fe575418ccde9e5ad;hp=d74c317f4b29d29783c5bb74eeb2e0a46328da8b;hb=fad79858d2f2d8d18c3a1a4d1f4bb87a0c49b1d1;hpb=1b772a147a183c09462f0d23e041b077f158fa0f

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index d74c317f4b29..ae02e421b75f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -25,6 +25,7 @@
 #include <linux/kallsyms.h>
 #include <linux/uaccess.h>
 #include <linux/ioport.h>
+#include <linux/cred.h>
 #include <net/addrconf.h>
 
 #include <asm/page.h>		/* for PAGE_SIZE */
@@ -892,10 +893,35 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 				spec.field_width = 2 * sizeof(void *);
 			return string(buf, end, "pK-error", spec);
 		}
-		if (!((kptr_restrict == 0) ||
-		      (kptr_restrict == 1 &&
-		       has_capability_noaudit(current, CAP_SYSLOG))))
+
+		switch (kptr_restrict) {
+		case 0:
+			/* Always print %pK values */
+			break;
+		case 1: {
+			/*
+			 * Only print the real pointer value if the current
+			 * process has CAP_SYSLOG and is running with the
+			 * same credentials it started with. This is because
+			 * access to files is checked at open() time, but %pK
+			 * checks permission at read() time. We don't want to
+			 * leak pointer values if a binary opens a file using
+			 * %pK and then elevates privileges before reading it.
+			 */
+			const struct cred *cred = current_cred();
+
+			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
+			    cred->euid != cred->uid ||
+			    cred->egid != cred->gid)
+				ptr = NULL;
+			break;
+		}
+		case 2:
+		default:
+			/* Always print 0's for %pK */
 			ptr = NULL;
+			break;
+		}
 		break;
 	}
 	spec.flags |= SMALL;