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| author | Roman Arutyunyan <arut@nginx.com> | 2024-08-12 18:20:43 +0400 |
|---|---|---|
| committer | Roman Arutyunyan <arut@nginx.com> | 2024-08-12 18:20:43 +0400 |
| commit | 3dc0fba5adec4c033eed76976f7275f2af7d5ddd (patch) | |
| tree | de65c44639aa78a3a61a23382db0edc460134010 | |
| parent | e1daadc3883ad94e0c450ad46e8f11ad5539dcfc (diff) | |
| download | nginx-3dc0fba5adec4c033eed76976f7275f2af7d5ddd.tar.gz nginx-3dc0fba5adec4c033eed76976f7275f2af7d5ddd.zip | |
Mp4: fixed buffer underread while updating stsz atom.
While cropping an stsc atom in ngx_http_mp4_crop_stsc_data(), a 32-bit integer
overflow could happen, which could result in incorrect seeking and a very large
value stored in "samples". This resulted in a large invalid value of
trak->end_chunk_samples. This value is further used to calculate the value of
trak->end_chunk_samples_size in ngx_http_mp4_update_stsz_atom(). While doing
this, a large invalid value of trak->end_chunk_samples could result in reading
memory before stsz atom start. This could potentially result in a segfault.
| -rw-r--r-- | src/http/modules/ngx_http_mp4_module.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c index 03175dea2..1cd017c27 100644 --- a/src/http/modules/ngx_http_mp4_module.c +++ b/src/http/modules/ngx_http_mp4_module.c @@ -3099,7 +3099,8 @@ static ngx_int_t ngx_http_mp4_crop_stsc_data(ngx_http_mp4_file_t *mp4, ngx_http_mp4_trak_t *trak, ngx_uint_t start) { - uint32_t start_sample, chunk, samples, id, next_chunk, n, + uint64_t n; + uint32_t start_sample, chunk, samples, id, next_chunk, prev_samples; ngx_buf_t *data, *buf; ngx_uint_t entries, target_chunk, chunk_samples; @@ -3160,7 +3161,7 @@ ngx_http_mp4_crop_stsc_data(ngx_http_mp4_file_t *mp4, "samples:%uD, id:%uD", start_sample, chunk, next_chunk - chunk, samples, id); - n = (next_chunk - chunk) * samples; + n = (uint64_t) (next_chunk - chunk) * samples; if (start_sample < n) { goto found; @@ -3182,7 +3183,7 @@ ngx_http_mp4_crop_stsc_data(ngx_http_mp4_file_t *mp4, "sample:%uD, chunk:%uD, chunks:%uD, samples:%uD", start_sample, chunk, next_chunk - chunk, samples); - n = (next_chunk - chunk) * samples; + n = (uint64_t) (next_chunk - chunk) * samples; if (start_sample > n) { ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0, |