[apparmor] [PATCH] parser: Quiet valgrind false positive

[Steve Beattie]

On Wed, Feb 05, 2014 at 01:22:42PM -0500, Tyler Hicks wrote:
> strlen() assumes that it can read an entire word but when a char array
> array does not end on a word boundary, it reads past the end of the
> array. This results in the following valgrind warning:
> 
>  Invalid read of size 4
>     at 0x40A162: yylex() (parser_lex.l:277)
>     by 0x40FA14: yyparse() (parser_yacc.c:1487)
>     by 0x40C5B9: process_profile(int, char const*) (parser_main.c:1003)
>     by 0x404074: main (parser_main.c:1340)
>   Address 0x578d870 is 16 bytes inside a block of size 18 alloc'd
>     at 0x4C2A420: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
>     by 0x53E31C9: strdup (strdup.c:42)
>     by 0x40A145: yylex() (parser_lex.l:276)
>     by 0x40FA14: yyparse() (parser_yacc.c:1487)
>     by 0x40C5B9: process_profile(int, char const*) (parser_main.c:1003)
>     by 0x404074: main (parser_main.c:1340)
> 
> This patch quiets the warning by not using strlen(). This can be done
> because yyleng already contains the length of string.
> 
> Signed-off-by: Tyler Hicks <tyhicks at canonical.com>

Yes, much better. Acked-by: Steve Beattie <steve at nxnw.org>

With that, we can get rid of the valgrind supression that applies for
that bit of code. Here's the patch to do that:

Signed-off-by: Steve Beattie <steve at nxnw.org>
---
 parser/tst/valgrind_simple.py |    9 ---------
 1 file changed, 9 deletions(-)

Index: b/parser/tst/valgrind_simple.py
===================================================================
--- a/parser/tst/valgrind_simple.py
+++ b/parser/tst/valgrind_simple.py
@@ -33,15 +33,6 @@ VALGRIND_SUPPRESSIONS = '''
 }
 
 {
-    valgrind-yylex-obsessive-overreads
-    Memcheck:Addr4
-    fun:_Z?yylex?
-    fun:_Z*yyparse*
-    fun:_Z*process_profile*
-    fun:main
-}
-
-{
     valgrind-serialize_profile-obsessive-overreads
     Memcheck:Addr4
     fun:_Z*sd_serialize_profile*

-- 
Steve Beattie
<sbeattie at ubuntu.com>
http://NxNW.org/~steve/
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