diff options
Diffstat (limited to 'src/liblzma/common/common.c')
| -rw-r--r-- | src/liblzma/common/common.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c index 10fc8840..8de37d00 100644 --- a/src/liblzma/common/common.c +++ b/src/liblzma/common/common.c @@ -289,13 +289,21 @@ lzma_code(lzma_stream *strm, lzma_action action) strm->next_in, &in_pos, strm->avail_in, strm->next_out, &out_pos, strm->avail_out, action); - strm->next_in += in_pos; - strm->avail_in -= in_pos; - strm->total_in += in_pos; + // Updating next_in and next_out has to be skipped when they are NULL + // to avoid null pointer + 0 (undefined behavior). Do this by checking + // in_pos > 0 and out_pos > 0 because this way NULL + non-zero (a bug) + // will get caught one way or other. + if (in_pos > 0) { + strm->next_in += in_pos; + strm->avail_in -= in_pos; + strm->total_in += in_pos; + } - strm->next_out += out_pos; - strm->avail_out -= out_pos; - strm->total_out += out_pos; + if (out_pos > 0) { + strm->next_out += out_pos; + strm->avail_out -= out_pos; + strm->total_out += out_pos; + } strm->internal->avail_in = strm->avail_in; |