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| author | Xi Wang <xi.wang@gmail.com> | 2013-01-22 17:49:29 -0500 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2013-01-23 13:51:27 +0200 |
| commit | 3cff53369acdb3bc0695dd6d5df51457fdaa16ce (patch) | |
| tree | 7a087bd477b07976adc2788a539241b2cd4ef98a | |
| parent | 2e4130037cf3b64921976fbff4579bda0e91dc87 (diff) | |
| download | ffmpeg-3cff53369acdb3bc0695dd6d5df51457fdaa16ce.tar.gz | |
rtmp: fix multiple broken overflow checks
Sanity checks like `data + size >= data_end || data + size < data' are
broken, because `data + size < data' assumes pointer overflow, which is
undefined behavior in C. Many compilers such as gcc/clang optimize such
checks away.
Use `size < 0 || size >= data_end - data' instead.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
| -rw-r--r-- | libavformat/rtmppkt.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/libavformat/rtmppkt.c b/libavformat/rtmppkt.c index aed188dcc7..a9d0a0d9f3 100644 --- a/libavformat/rtmppkt.c +++ b/libavformat/rtmppkt.c @@ -356,11 +356,11 @@ int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end) data++; break; } - if (data + size >= data_end || data + size < data) + if (size < 0 || size >= data_end - data) return -1; data += size; t = ff_amf_tag_size(data, data_end); - if (t < 0 || data + t >= data_end) + if (t < 0 || t >= data_end - data) return -1; data += t; } @@ -389,7 +389,7 @@ int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end, int size = bytestream_get_be16(&data); if (!size) break; - if (data + size >= data_end || data + size < data) + if (size < 0 || size >= data_end - data) return -1; data += size; if (size == namelen && !memcmp(data-size, name, namelen)) { @@ -410,7 +410,7 @@ int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end, return 0; } len = ff_amf_tag_size(data, data_end); - if (len < 0 || data + len >= data_end || data + len < data) + if (len < 0 || len >= data_end - data) return -1; data += len; } @@ -481,13 +481,13 @@ static void ff_amf_tag_contents(void *ctx, const uint8_t *data, const uint8_t *d data++; break; } - if (data + size >= data_end || data + size < data) + if (size < 0 || size >= data_end - data) return; data += size; av_log(ctx, AV_LOG_DEBUG, " %s: ", buf); ff_amf_tag_contents(ctx, data, data_end); t = ff_amf_tag_size(data, data_end); - if (t < 0 || data + t >= data_end) + if (t < 0 || t >= data_end - data) return; data += t; } |