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| author |   Lasse Collin <lasse.collin@tukaani.org> | 2021-10-11 05:31:39 +0800 |
|---|---|---|
| committer |   Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-10-19 23:44:30 +0800 |
| commit | 83d3c4f22a36d005b55f44628f46cc0d319a75e8 (patch) | |
| tree | 148fa15f84c3fcea07fa515dcc305494417a46b0 /lib/decompress_unxz.c | |
| parent | erofs: introduce readmore decompression strategy (diff) | |
| download | linux-dev-83d3c4f22a36d005b55f44628f46cc0d319a75e8.tar.xz linux-dev-83d3c4f22a36d005b55f44628f46cc0d319a75e8.zip | |
lib/xz: Avoid overlapping memcpy() with invalid input with in-place decompression
With valid files, the safety margin described in lib/decompress_unxz.c
ensures that these buffers cannot overlap. But if the uncompressed size
of the input is larger than the caller thought, which is possible when
the input file is invalid/corrupt, the buffers can overlap. Obviously
the result will then be garbage (and usually the decoder will return
an error too) but no other harm will happen when such an over-run occurs.
This change only affects uncompressed LZMA2 chunks and so this
should have no effect on performance.
Link: https://lore.kernel.org/r/20211010213145.17462-2-xiang@kernel.org
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'lib/decompress_unxz.c')
| -rw-r--r-- | lib/decompress_unxz.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/decompress_unxz.c b/lib/decompress_unxz.c index a2f38e23004a..f7a3dc13316a 100644 --- a/lib/decompress_unxz.c +++ b/lib/decompress_unxz.c @@ -167,7 +167,7 @@ * memeq and memzero are not used much and any remotely sane implementation * is fast enough. memcpy/memmove speed matters in multi-call mode, but * the kernel image is decompressed in single-call mode, in which only - * memcpy speed can matter and only if there is a lot of uncompressible data + * memmove speed can matter and only if there is a lot of uncompressible data * (LZMA2 stores uncompressible chunks in uncompressed form). Thus, the * functions below should just be kept small; it's probably not worth * optimizing for speed. |