ss: avoid passing negative numbers to malloc

Example:

$ ss state established \( sport = :4060  or sport = :4061 or sport = :4062  or sport = :4063 or sport = :4064  or sport = :4065 or sport = :4066  or sport = :4067 \)  > /dev/null
Aborted

In the example above ssfilter_bytecompile(...) will return (int)136.
char l1 = 136; means -120 which will result in a negative number
being passed to malloc at misc/ss.c:913.

Simply declare l1 and l2 as integers to avoid the char overflow.

This is one of the issues originally reported in http://bugs.debian.org/511720

Fix the same problem in other code paths as well (thanks to Eric Dumazet).

Reported-by: Andreas Schuldei <andreas@debian.org>
Signed-off-by: Andreas Henriksson <andreas@fatal.se>
Reviewed-by: Eric Dumazet <edumazet@google.com>

diff --git a/misc/ss.c b/misc/ss.c
index c0369f11ef40af5662a21aee100bfe83b6d0114e..6f38ae7ed3524b5b5ad62e9a9e810dd8ba1ad50a 100644 (file)
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -894,7 +894,8 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode)
 
                case SSF_AND:
        {
-               char *a1, *a2, *a, l1, l2;
+               char *a1, *a2, *a;
+               int l1, l2;
                l1 = ssfilter_bytecompile(f->pred, &a1);
                l2 = ssfilter_bytecompile(f->post, &a2);
                if (!(a = malloc(l1+l2))) abort();
@@ -907,7 +908,8 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode)
        }
                case SSF_OR:
        {
-               char *a1, *a2, *a, l1, l2;
+               char *a1, *a2, *a;
+               int l1, l2;
                l1 = ssfilter_bytecompile(f->pred, &a1);
                l2 = ssfilter_bytecompile(f->post, &a2);
                if (!(a = malloc(l1+l2+4))) abort();
@@ -920,7 +922,8 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode)
        }
                case SSF_NOT:
        {
-               char *a1, *a, l1;
+               char *a1, *a;
+               int l1;
                l1 = ssfilter_bytecompile(f->pred, &a1);
                if (!(a = malloc(l1+4))) abort();
                memcpy(a, a1, l1);