[binutils-gdb] demand_copy_C_string NUL check

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=70433886683b67b5a28abe35eac7e9ab82a4a9e4

commit 70433886683b67b5a28abe35eac7e9ab82a4a9e4
Author: Alan Modra <amodra@gmail.com>
Date:   Tue Feb 16 14:32:36 2021 +1030

    demand_copy_C_string NUL check
    
            * read.c (demand_copy_C_string): Really check for embedded zeros.

Diff:
---
 gas/ChangeLog | 4 ++++
 gas/read.c    | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 9c6fe109d92..f4c9d0a0fa6 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,7 @@
+2021-02-16  Alan Modra  <amodra@gmail.com>
+
+	* read.c (demand_copy_C_string): Really check for embedded zeros.
+
 2021-02-15  Andreas Krebbel  <krebbel@linux.ibm.com>
 
 	* config/tc-s390.c (s390_parse_cpu): New entry for arch14.
diff --git a/gas/read.c b/gas/read.c
index ede811b0a03..3e760653289 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -5743,12 +5743,12 @@ demand_copy_C_string (int *len_pointer)
 
       for (len = *len_pointer; len > 0; len--)
 	{
-	  if (*s == 0)
+	  if (s[len - 1] == 0)
 	    {
 	      s = 0;
-	      len = 1;
 	      *len_pointer = 0;
 	      as_bad (_("this string may not contain \'\\0\'"));
+	      break;
 	    }
 	}
     }