From: Albin Tonnerre on
This patch fixes 2 issues with the LZO decompressor:
- It doesn't handle the case where a block isn't compressed at all. In
this case, calling lzo1x_decompress_safe will fail, so we need to
just use memcpy() instead (the upstream LZO code does something
similar)
- Since commit 54291362d2a5738e1b0495df2abcb9e6b0563a3f, the
decompressor return code is checked in the init/initramfs.c
The LZO decompressor didn't return the expected value, causing the
initramfs code to falsely believe a decompression error occured

Signed-off-by: Albin Tonnerre <albin.tonnerre(a)free-electrons.com>
Tested-By: bert schulze <spambemyguest(a)googlemail.com>
--
lib/decompress_unlzo.c | 22 +++++++++++++++-------
1 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/lib/decompress_unlzo.c b/lib/decompress_unlzo.c
index db521f4..bcb3a4b 100644
--- a/lib/decompress_unlzo.c
+++ b/lib/decompress_unlzo.c
@@ -97,7 +97,7 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
u32 src_len, dst_len;
size_t tmp;
u8 *in_buf, *in_buf_save, *out_buf;
- int obytes_processed = 0;
+ int ret = -1;

set_error_fn(error_fn);

@@ -174,15 +174,22 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,

/* decompress */
tmp = dst_len;
- r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
+
+ /* When the input data is not compressed at all,
+ * lzo1x_decompress_safe will fail, so call memcpy()
+ * instead */
+ if (unlikely(dst_len == src_len))
+ memcpy(out_buf, in_buf, src_len);
+ else {
+ r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
out_buf, &tmp);

- if (r != LZO_E_OK || dst_len != tmp) {
- error("Compressed data violation");
- goto exit_2;
+ if (r != LZO_E_OK || dst_len != tmp) {
+ error("Compressed data violation");
+ goto exit_2;
+ }
}

- obytes_processed += dst_len;
if (flush)
flush(out_buf, dst_len);
if (output)
@@ -196,6 +203,7 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
in_buf += src_len;
}

+ ret = 0;
exit_2:
if (!input)
free(in_buf);
@@ -203,7 +211,7 @@ exit_1:
if (!output)
free(out_buf);
exit:
- return obytes_processed;
+ return ret;
}

#define decompress unlzo
--
1.7.0.4

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