Fix illegal memory access bug in nm when run on a corrupt binary.

PR binutils/21150 * nm.c (file_symbol): Add test of string length before testing string characters.
10 years ago · c12214021d
2 changed files with 8 additions and 1 deletions
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@ -1,3 +1,9 @@
+2017-02-13  Nick Clifton  <nickc@redhat.com>
+
+	PR binutils/21150
+	* nm.c (file_symbol): Add test of string length before testing
+	string characters.
+
 2017-02-13  Nick Clifton  <nickc@redhat.com>

 	PR binutils/21135
--- a/binutils/nm.c
+++ b/binutils/nm.c
@ -685,7 +685,8 @@ size_forward1 (const void *P_x, const void *P_y)

 #define file_symbol(s, sn, snl)			\
  (((s)->flags & BSF_FILE) != 0			\
-   || ((sn)[(snl) - 2] == '.'			\
+   || ((snl) > 2				\
+       && (sn)[(snl) - 2] == '.'		\
       && ((sn)[(snl) - 1] == 'o'		\
 	   || (sn)[(snl) - 1] == 'a')))