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| author | Denys Vlasenko | 2021-06-15 15:07:57 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2021-06-15 15:14:00 +0200 |
| commit | 04f052c56ded5ab6a904e3a264a73dc0412b2e78 (patch) | |
| tree | 607ac1970ec5f880b317f2937f9f664e52d65c44 /archival | |
| parent | 4d4fc5ca5ee4faae5dc4237f801d9527a3fb20cc (diff) | |
| download | busybox-04f052c56ded5ab6a904e3a264a73dc0412b2e78.zip busybox-04f052c56ded5ab6a904e3a264a73dc0412b2e78.tar.gz | |
unlzma: fix a case where we could read before beginning of buffer
Testcase:
21 01 01 00 00 00 00 00 e7 01 01 01 ef 00 df b6
00 17 02 10 11 0f ff 00 16 00 00
Unfortunately, the bug is not reliably causing a segfault,
the behavior depends on what's in memory before the buffer.
function old new delta
unpack_lzma_stream 2762 2768 +6
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'archival')
| -rw-r--r-- | archival/libarchive/decompress_unlzma.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/archival/libarchive/decompress_unlzma.c b/archival/libarchive/decompress_unlzma.c index 0744f23..fb5aac8 100644 --- a/archival/libarchive/decompress_unlzma.c +++ b/archival/libarchive/decompress_unlzma.c @@ -290,8 +290,11 @@ unpack_lzma_stream(transformer_state_t *xstate) uint32_t pos; pos = buffer_pos - rep0; - if ((int32_t)pos < 0) + if ((int32_t)pos < 0) { pos += header.dict_size; + if ((int32_t)pos < 0) + goto bad; + } match_byte = buffer[pos]; do { int bit; |