[PATCH v2] hcom: fix crash on input with corrupt dictionary (CVE-2017-11358)

[PATCH v2] hcom: fix crash on input with corrupt dictionary (CVE-2017-11358)

[Mans Rullgard]

The previous patch was incorrect.
---
 src/hcom.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/hcom.c b/src/hcom.c
index e76820e9333f..be17d9d2e58e 100644
--- a/src/hcom.c
+++ b/src/hcom.c
@@ -73,6 +73,14 @@ typedef struct {
   size_t pos;                /* Where next byte goes */
 } priv_t;
 
+static int dictvalid(int n, int size, int left, int right)
+{
+        if (n > 0 && left < 0)
+                return 1;
+
+        return (unsigned)left < size && (unsigned)right < size;
+}
+
 static int startread(sox_format_t * ft)
 {
         priv_t *p = (priv_t *) ft->priv;
@@ -150,6 +158,11 @@ static int startread(sox_format_t * ft)
                 lsx_debug("%d %d",
                        p->dictionary[i].dict_leftson,
                        p->dictionary[i].dict_rightson);
+                if (!dictvalid(i, dictsize, p->dictionary[i].dict_leftson,
+                               p->dictionary[i].dict_rightson)) {
+                        lsx_fail_errno(ft, SOX_EHDR, "Invalid dictionary");
+                        return SOX_EOF;
+                }
         }
         rc = lsx_skipbytes(ft, (size_t) 1); /* skip pad byte */
         if (rc)
-- 
2.17.0


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
SoX-devel mailing list
SoX-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sox-devel