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
........

Merged revisions 403015 from http://svn.asterisk.org/svn/asterisk/branches/11
........

Merged revisions 403016 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@403017 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 29 insertions, 30 deletions

diff --git a/main/translate.c b/main/translate.c
index 96019f1c7..df2754d11 100644
--- a/main/translate.c
+++ b/main/translate.c
@@ -518,41 +518,40 @@ 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;
 }