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-rw-r--r--src/liblzma/common/block_decoder.c5
-rw-r--r--src/liblzma/common/block_encoder.c7
-rw-r--r--src/liblzma/common/common.c20
-rw-r--r--src/liblzma/common/index_decoder.c13
-rw-r--r--src/liblzma/common/index_encoder.c11
-rw-r--r--src/liblzma/common/index_hash.c13
-rw-r--r--src/liblzma/delta/delta_decoder.c7
-rw-r--r--src/liblzma/delta/delta_encoder.c12
-rw-r--r--src/liblzma/simple/simple_coder.c6
9 files changed, 72 insertions, 22 deletions
diff --git a/src/liblzma/common/block_decoder.c b/src/liblzma/common/block_decoder.c
index 4827e0f0..be647d48 100644
--- a/src/liblzma/common/block_decoder.c
+++ b/src/liblzma/common/block_decoder.c
@@ -123,7 +123,10 @@ block_decode(void *coder_ptr, const lzma_allocator *allocator,
return LZMA_DATA_ERROR;
}
- if (!coder->ignore_check)
+ // Don't waste time updating the integrity check if it will be
+ // ignored. Also skip it if no new output was produced. This
+ // avoids null pointer + 0 (undefined behavior) when out == 0.
+ if (!coder->ignore_check && out_used > 0)
lzma_check_update(&coder->check, coder->block->check,
out + out_start, out_used);
diff --git a/src/liblzma/common/block_encoder.c b/src/liblzma/common/block_encoder.c
index 520ecc5a..4a136ef6 100644
--- a/src/liblzma/common/block_encoder.c
+++ b/src/liblzma/common/block_encoder.c
@@ -77,8 +77,11 @@ block_encode(void *coder_ptr, const lzma_allocator *allocator,
// checked it at the beginning of this function.
coder->uncompressed_size += in_used;
- lzma_check_update(&coder->check, coder->block->check,
- in + in_start, in_used);
+ // Call lzma_check_update() only if input was consumed. This
+ // avoids null pointer + 0 (undefined behavior) when in == 0.
+ if (in_used > 0)
+ lzma_check_update(&coder->check, coder->block->check,
+ in + in_start, in_used);
if (ret != LZMA_STREAM_END || action == LZMA_SYNC_FLUSH)
return ret;
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;
diff --git a/src/liblzma/common/index_decoder.c b/src/liblzma/common/index_decoder.c
index cc07a1b8..868d3d27 100644
--- a/src/liblzma/common/index_decoder.c
+++ b/src/liblzma/common/index_decoder.c
@@ -200,9 +200,16 @@ index_decode(void *coder_ptr, const lzma_allocator *allocator,
}
out:
- // Update the CRC32,
- coder->crc32 = lzma_crc32(in + in_start,
- *in_pos - in_start, coder->crc32);
+ // Update the CRC32.
+ //
+ // Avoid null pointer + 0 (undefined behavior) in "in + in_start".
+ // In such a case we had no input and thus in_used == 0.
+ {
+ const size_t in_used = *in_pos - in_start;
+ if (in_used > 0)
+ coder->crc32 = lzma_crc32(in + in_start,
+ in_used, coder->crc32);
+ }
return ret;
}
diff --git a/src/liblzma/common/index_encoder.c b/src/liblzma/common/index_encoder.c
index ac97d0ce..364522ce 100644
--- a/src/liblzma/common/index_encoder.c
+++ b/src/liblzma/common/index_encoder.c
@@ -153,8 +153,15 @@ index_encode(void *coder_ptr,
out:
// Update the CRC32.
- coder->crc32 = lzma_crc32(out + out_start,
- *out_pos - out_start, coder->crc32);
+ //
+ // Avoid null pointer + 0 (undefined behavior) in "out + out_start".
+ // In such a case we had no input and thus out_used == 0.
+ {
+ const size_t out_used = *out_pos - out_start;
+ if (out_used > 0)
+ coder->crc32 = lzma_crc32(out + out_start,
+ out_used, coder->crc32);
+ }
return ret;
}
diff --git a/src/liblzma/common/index_hash.c b/src/liblzma/common/index_hash.c
index 5c9d3140..18556a1a 100644
--- a/src/liblzma/common/index_hash.c
+++ b/src/liblzma/common/index_hash.c
@@ -325,9 +325,16 @@ lzma_index_hash_decode(lzma_index_hash *index_hash, const uint8_t *in,
}
out:
- // Update the CRC32,
- index_hash->crc32 = lzma_crc32(in + in_start,
- *in_pos - in_start, index_hash->crc32);
+ // Update the CRC32.
+ //
+ // Avoid null pointer + 0 (undefined behavior) in "in + in_start".
+ // In such a case we had no input and thus in_used == 0.
+ {
+ const size_t in_used = *in_pos - in_start;
+ if (in_used > 0)
+ index_hash->crc32 = lzma_crc32(in + in_start,
+ in_used, index_hash->crc32);
+ }
return ret;
}
diff --git a/src/liblzma/delta/delta_decoder.c b/src/liblzma/delta/delta_decoder.c
index 13d8a28f..77cf65cc 100644
--- a/src/liblzma/delta/delta_decoder.c
+++ b/src/liblzma/delta/delta_decoder.c
@@ -42,7 +42,12 @@ delta_decode(void *coder_ptr, const lzma_allocator *allocator,
in, in_pos, in_size, out, out_pos, out_size,
action);
- decode_buffer(coder, out + out_start, *out_pos - out_start);
+ // out might be NULL. In that case size == 0. Null pointer + 0 is
+ // undefined behavior so skip the call in that case as it would
+ // do nothing anyway.
+ const size_t size = *out_pos - out_start;
+ if (size > 0)
+ decode_buffer(coder, out + out_start, size);
return ret;
}
diff --git a/src/liblzma/delta/delta_encoder.c b/src/liblzma/delta/delta_encoder.c
index 38416515..056bf746 100644
--- a/src/liblzma/delta/delta_encoder.c
+++ b/src/liblzma/delta/delta_encoder.c
@@ -63,7 +63,12 @@ delta_encode(void *coder_ptr, const lzma_allocator *allocator,
const size_t out_avail = out_size - *out_pos;
const size_t size = my_min(in_avail, out_avail);
- copy_and_encode(coder, in + *in_pos, out + *out_pos, size);
+ // in and out might be NULL. In such cases size == 0.
+ // Null pointer + 0 is undefined behavior so skip
+ // the call in that case as it would do nothing anyway.
+ if (size > 0)
+ copy_and_encode(coder, in + *in_pos, out + *out_pos,
+ size);
*in_pos += size;
*out_pos += size;
@@ -78,7 +83,10 @@ delta_encode(void *coder_ptr, const lzma_allocator *allocator,
in, in_pos, in_size, out, out_pos, out_size,
action);
- encode_in_place(coder, out + out_start, *out_pos - out_start);
+ // Like above, avoid null pointer + 0.
+ const size_t size = *out_pos - out_start;
+ if (size > 0)
+ encode_in_place(coder, out + out_start, size);
}
return ret;
diff --git a/src/liblzma/simple/simple_coder.c b/src/liblzma/simple/simple_coder.c
index 4f499bef..ed2d7fb0 100644
--- a/src/liblzma/simple/simple_coder.c
+++ b/src/liblzma/simple/simple_coder.c
@@ -139,9 +139,11 @@ simple_code(void *coder_ptr, const lzma_allocator *allocator,
return ret;
}
- // Filter out[].
+ // Filter out[] unless there is nothing to filter.
+ // This way we avoid null pointer + 0 (undefined behavior)
+ // when out == NULL.
const size_t size = *out_pos - out_start;
- const size_t filtered = call_filter(
+ const size_t filtered = size == 0 ? 0 : call_filter(
coder, out + out_start, size);
const size_t unfiltered = size - filtered;
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-20 04:28:53 +0000