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| author | Lasse Collin <lasse.collin@tukaani.org> | 2022-09-09 13:51:57 +0300 |
|---|---|---|
| committer | Lasse Collin <lasse.collin@tukaani.org> | 2022-09-09 13:51:57 +0300 |
| commit | f8ee61e74eb40600445fdb601c374d582e1e9c8a (patch) | |
| tree | 7f2d7b0545b4824a91b3947b220b77987c791ba3 /src/liblzma/api | |
| parent | liblzma: lzma_index_append: Add missing integer overflow check. (diff) | |
| download | xz-f8ee61e74eb40600445fdb601c374d582e1e9c8a.tar.xz | |
liblzma: lzma_filters_copy: Keep dest[] unmodified if an error occurs.
lzma_stream_encoder() and lzma_stream_encoder_mt() always assumed
this. Before this patch, failing lzma_filters_copy() could result
in free(invalid_pointer) or invalid memory reads in stream_encoder.c
or stream_encoder_mt.c.
To trigger this, allocating memory for a filter options structure
has to fail. These are tiny allocations so in practice they very
rarely fail.
Certain badness in the filter chain array could also make
lzma_filters_copy() fail but both stream_encoder.c and
stream_encoder_mt.c validate the filter chain before
trying to copy it, so the crash cannot occur this way.
Diffstat (limited to 'src/liblzma/api')
| -rw-r--r-- | src/liblzma/api/lzma/filter.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/liblzma/api/lzma/filter.h b/src/liblzma/api/lzma/filter.h index 8c859314..04825c65 100644 --- a/src/liblzma/api/lzma/filter.h +++ b/src/liblzma/api/lzma/filter.h @@ -108,7 +108,9 @@ extern LZMA_API(lzma_bool) lzma_filter_decoder_is_supported(lzma_vli id) * need to be initialized by the caller in any way. * * If an error occurs, memory possibly already allocated by this function - * is always freed. + * is always freed. liblzma versions older than 5.2.7 may modify the dest + * array and leave its contents in an undefined state if an error occurs. + * liblzma 5.2.7 and newer only modify the dest array when returning LZMA_OK. * * \return - LZMA_OK * - LZMA_MEM_ERROR |