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author | Nick Mathewson <nickm@torproject.org> | 2017-06-20 12:26:57 -0400 |
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committer | Nick Mathewson <nickm@torproject.org> | 2017-06-20 12:26:57 -0400 |
commit | 9328bd524e38befe240fd729a9febb4dfe8b5be4 (patch) | |
tree | 93510123bf30cf23af636cb7f9c4a62b7e84970d /src/common | |
parent | 945256188ab3a9b5842455f714d51e1871b0bf69 (diff) | |
download | tor-9328bd524e38befe240fd729a9febb4dfe8b5be4.tar.gz tor-9328bd524e38befe240fd729a9febb4dfe8b5be4.zip |
Enforce the rule that COMPRESS_OK means progress was made.
If COMPRESS_OK occurs but data is neither consumed nor generated,
treat it as a BUG and a COMPRESS_ERROR.
This change is meant to prevent infinite loops in the case where
we've made a mistake in one of our compression backends.
Closes ticket 22672.
Diffstat (limited to 'src/common')
-rw-r--r-- | src/common/compress.c | 36 |
1 files changed, 25 insertions, 11 deletions
diff --git a/src/common/compress.c b/src/common/compress.c index c16d1b51ee..46aa1d52ba 100644 --- a/src/common/compress.c +++ b/src/common/compress.c @@ -548,28 +548,42 @@ tor_compress_process(tor_compress_state_t *state, int finish) { tor_assert(state != NULL); + const size_t in_len_orig = *in_len; + const size_t out_len_orig = *out_len; + tor_compress_output_t rv; switch (state->method) { case GZIP_METHOD: case ZLIB_METHOD: - return tor_zlib_compress_process(state->u.zlib_state, - out, out_len, in, in_len, - finish); + rv = tor_zlib_compress_process(state->u.zlib_state, + out, out_len, in, in_len, + finish); + break; case LZMA_METHOD: - return tor_lzma_compress_process(state->u.lzma_state, - out, out_len, in, in_len, - finish); + rv =tor_lzma_compress_process(state->u.lzma_state, + out, out_len, in, in_len, + finish); + break; case ZSTD_METHOD: - return tor_zstd_compress_process(state->u.zstd_state, - out, out_len, in, in_len, - finish); + rv = tor_zstd_compress_process(state->u.zstd_state, + out, out_len, in, in_len, + finish); + break; case NO_METHOD: - return tor_cnone_compress_process(out, out_len, in, in_len, - finish); + rv = tor_cnone_compress_process(out, out_len, in, in_len, + finish); + break; + default: case UNKNOWN_METHOD: goto err; } + if (BUG((rv == TOR_COMPRESS_OK) && + *in_len == in_len_orig && + *out_len == out_len_orig)) { + return TOR_COMPRESS_ERROR; + } + return rv; err: return TOR_COMPRESS_ERROR; } |