---

yaml --- r: 372895 b: refs/heads/master c: 6e15eb3 h: refs/heads/master i: 372893: 99bdcba 372891: d67bf74 372887: 619d769 372879: efe0a8e 372863: d05a1aa v: v3
git-mirror · May 4, 2013 · 58a754b · 58a754b
1 parent 815fafa
commit 58a754b
Show file tree

Hide file tree

Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 741a698f420c34c458294a6accecfbad702a7c52
+refs/heads/master: 6e15eb3ba6c0249c9e8c783517d131b47db995ca
diff --git a/trunk/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/trunk/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -442,8 +442,18 @@ static int branch_type(unsigned long from, unsigned long to)
 			return X86_BR_NONE;
 
 		addr = buf;
-	} else
-		addr = (void *)from;
+	} else {
+		/*
+		 * The LBR logs any address in the IP, even if the IP just
+		 * faulted. This means userspace can control the from address.
+		 * Ensure we don't blindy read any address by validating it is
+		 * a known text address.
+		 */
+		if (kernel_text_address(from))
+			addr = (void *)from;
+		else
+			return X86_BR_NONE;
+	}
 
 	/*
 	 * decoder needs to know the ABI especially