translate: Move freeing of frame to after it is used.

When translating from one format to another it is possible
to inform the translation function that the source frame should
be freed. This was previously done immediately but shortly
afterwards the frame that was freed was accessed and used again.

This change moves code around a bit so that the frame is now
freed after it has been completely used.

(closes issue ASTERISK-22788)
Reported by: Corey Farrell
Patches:
	translate-access-after-free-11up.patch uploaded by coreyfarrell (license 5909)
	translate-access-after-free-1.8.patch uploaded by coreyfarrell (license 5909)
........

Merged revisions 403014 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@403015 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/translate.c b/main/translate.c
index 8901e779cba7bfe0daca75492cf1b6b9f1c58546..84e24e56fb2e5f817cf55196d21e5cfe69b26efa 100644 (file)
--- a/main/translate.c
+++ b/main/translate.c
@@ -521,41 +521,40 @@ struct ast_frame *ast_translate(struct ast_trans_pvt *path, struct ast_frame *f,
                }
                out = p->t->frameout(p);
        }
-       if (consume) {
-               ast_frfree(f);
-       }
-       if (out == NULL) {
-               return NULL;
-       }
-       /* we have a frame, play with times */
-       if (!ast_tvzero(delivery)) {
-               /* Regenerate prediction after a discontinuity */
-               if (ast_tvzero(path->nextout)) {
-                       path->nextout = ast_tvnow();
-               }
+       if (out) {
+               /* we have a frame, play with times */
+               if (!ast_tvzero(delivery)) {
+                       /* Regenerate prediction after a discontinuity */
+                       if (ast_tvzero(path->nextout)) {
+                               path->nextout = ast_tvnow();
+                       }
 
-               /* Use next predicted outgoing timestamp */
-               out->delivery = path->nextout;
+                       /* Use next predicted outgoing timestamp */
+                       out->delivery = path->nextout;
 
-               /* Predict next outgoing timestamp from samples in this
-                  frame. */
-               path->nextout = ast_tvadd(path->nextout, ast_samp2tv(out->samples, ast_format_rate(&out->subclass.format)));
-               if (f->samples != out->samples && ast_test_flag(out, AST_FRFLAG_HAS_TIMING_INFO)) {
-                       ast_debug(4, "Sample size different %u vs %u\n", f->samples, out->samples);
-                       ast_clear_flag(out, AST_FRFLAG_HAS_TIMING_INFO);
+                       /* Predict next outgoing timestamp from samples in this
+                          frame. */
+                       path->nextout = ast_tvadd(path->nextout, ast_samp2tv(out->samples, ast_format_rate(&out->subclass.format)));
+                       if (f->samples != out->samples && ast_test_flag(out, AST_FRFLAG_HAS_TIMING_INFO)) {
+                               ast_debug(4, "Sample size different %u vs %u\n", f->samples, out->samples);
+                               ast_clear_flag(out, AST_FRFLAG_HAS_TIMING_INFO);
+                       }
+               } else {
+                       out->delivery = ast_tv(0, 0);
+                       ast_set2_flag(out, has_timing_info, AST_FRFLAG_HAS_TIMING_INFO);
+                       if (has_timing_info) {
+                               out->ts = ts;
+                               out->len = len;
+                               out->seqno = seqno;
+                       }
                }
-       } else {
-               out->delivery = ast_tv(0, 0);
-               ast_set2_flag(out, has_timing_info, AST_FRFLAG_HAS_TIMING_INFO);
-               if (has_timing_info) {
-                       out->ts = ts;
-                       out->len = len;
-                       out->seqno = seqno;
+               /* Invalidate prediction if we're entering a silence period */
+               if (out->frametype == AST_FRAME_CNG) {
+                       path->nextout = ast_tv(0, 0);
                }
        }
-       /* Invalidate prediction if we're entering a silence period */
-       if (out->frametype == AST_FRAME_CNG) {
-               path->nextout = ast_tv(0, 0);
+       if (consume) {
+               ast_frfree(f);
        }
        return out;
 }