From: Andre Noll <maan@tuebingen.mpg.de>
Date: Wed, 29 Jun 2022 11:38:02 +0000 (+0200)
Subject: mp4: Don't abort on truncated files.
X-Git-Tag: v0.7.1~7^2
X-Git-Url: http://git.tuebingen.mpg.de/?a=commitdiff_plain;h=7944326236f20f9ecccfe6ed0e471d665aba0123;p=paraslash.git

mp4: Don't abort on truncated files.

If the source file got truncated it may happen that a chunk cannot
be read because the computed file offset is beyond EOF. Currently,
aac_afh_get_chunk() aborts in this case because we assert that the
file offset is within range. Return a proper error code instead and
also change aac_get_file_info() to bail out if aac_afh_get_chunk()
returns negative.
---

diff --git a/aac_afh.c b/aac_afh.c
index 7be441ab..79fa30dd 100644
--- a/aac_afh.c
+++ b/aac_afh.c
@@ -101,7 +101,8 @@ static int aac_afh_get_chunk(uint32_t chunk_num, void *afh_context,
 	ret = mp4_get_sample_size(c->mp4, chunk_num, &ss);
 	if (ret < 0)
 		return ret;
-	assert(ss + offset <= c->mapsize);
+	if (ss + offset > c->mapsize) /* file got truncated?! */
+		return -E_MP4_CORRUPT;
 	*buf = c->map + offset;
 	*len = ss;
 	return 1;
@@ -141,18 +142,21 @@ static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 
 	afhi->max_chunk_size = 0;
 	for (n = 0; n < afhi->chunks_total; n++) {
-		if (aac_afh_get_chunk(n, c, &buf, &len) < 0)
-			break;
+		ret = aac_afh_get_chunk(n, c, &buf, &len);
+		if (ret < 0)
+			goto out;
 		afhi->max_chunk_size = PARA_MAX(afhi->max_chunk_size, len);
 	}
 	milliseconds = mp4_get_duration(c->mp4);
 	afhi->seconds_total = milliseconds / 1000;
 	ms2tv(milliseconds / afhi->chunks_total, &afhi->chunk_tv);
-	if (aac_afh_get_chunk(0, c, &buf, &len) >= 0)
-		numbytes -= buf - map;
+	if (aac_afh_get_chunk(0, c, &buf, &len) < 0)
+		goto out;
+	numbytes -= buf - map;
 	afhi->bitrate = 8 * numbytes / afhi->seconds_total / 1000;
 	aac_afh_get_taginfo(c->mp4, &afhi->tags);
 	ret = 1;
+out:
 	aac_afh_close(c);
 	return ret;
 }