diff options
| author | Xi Wang <xi.wang@gmail.com> | 2012-11-14 03:25:41 -0500 |
|---|---|---|
| committer | Anton Khirnov <anton@khirnov.net> | 2012-11-21 14:35:26 +0100 |
| commit | b655cfefafd565590bfc5976b9ce8dd141b3c41c (patch) | |
| tree | 9deaab26b20f1fbc2e3e6e51eb6e3f80eaf46aa0 /libavformat/apetag.c | |
| parent | 17fecb4a59926fc85d76efd0d0405f1aa84e429b (diff) | |
apetag: fix error handling in ff_ape_parse_tag()
The following error handling is broken due to signedness.
int file_size;
uint32_t tag_bytes;
int64_t tag_start;
...
tag_start = file_size - tag_bytes - APE_TAG_FOOTER_BYTES;
if (tag_start < 0) { ... }
Note that tag_bytes is unsigned, which makes the right-hand side of
`tag_start = ...' unsigned, too. The 32-bit unsigned value is then
zero-extended to 64 bits. Therefore, tag_start must be non-negative,
and the check (tag_start < 0) is always false, which breaks the error
handling. This patch fixes the check.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Diffstat (limited to 'libavformat/apetag.c')
| -rw-r--r-- | libavformat/apetag.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/libavformat/apetag.c b/libavformat/apetag.c index 28a3ff7753..0d2cb973fb 100644 --- a/libavformat/apetag.c +++ b/libavformat/apetag.c @@ -144,11 +144,11 @@ int64_t ff_ape_parse_tag(AVFormatContext *s) return 0; } - tag_start = file_size - tag_bytes - APE_TAG_FOOTER_BYTES; - if (tag_start < 0) { + if (tag_bytes > file_size - APE_TAG_FOOTER_BYTES) { av_log(s, AV_LOG_ERROR, "Invalid tag size %u.\n", tag_bytes); return 0; } + tag_start = file_size - tag_bytes - APE_TAG_FOOTER_BYTES; fields = avio_rl32(pb); /* number of fields */ if (fields > 65536) { |