lz4: fix system halt at boot kernel on x86_64

Sometimes, on x86_64, decompression fails with the following
error:

Decompressing Linux...

Decoding failed

 -- System halted

This condition is not needed for a 64bit kernel(from commit d5e7caf):

if( ... ||
    (op + COPYLENGTH) > oend)
    goto _output_error

macro LZ4_SECURE_COPY() tests op and does not copy any data
when op exceeds the value.

added by analogy to lz4_uncompress_unknownoutputsize(...)

Signed-off-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Tested-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Tested-by: Caleb Jorden <cjorden@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
index 26cc602..6d940c7 100644 (file)
--- a/lib/lz4/lz4_decompress.c
+++ b/lib/lz4/lz4_decompress.c
@@ -140,8 +140,12 @@ static int lz4_uncompress(const char *source, char *dest, int osize)
                        /* Error: request to write beyond destination buffer */
                        if (cpy > oend)
                                goto _output_error;
+#if LZ4_ARCH64
+                       if ((ref + COPYLENGTH) > oend)
+#else
                        if ((ref + COPYLENGTH) > oend ||
                                        (op + COPYLENGTH) > oend)
+#endif
                                goto _output_error;
                        LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
                        while (op < cpy)
@@ -266,7 +270,13 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
                if (cpy > oend - COPYLENGTH) {
                        if (cpy > oend)
                                goto _output_error; /* write outside of buf */
-
+#if LZ4_ARCH64
+                       if ((ref + COPYLENGTH) > oend)
+#else
+                       if ((ref + COPYLENGTH) > oend ||
+                                       (op + COPYLENGTH) > oend)
+#endif
+                               goto _output_error;
                        LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
                        while (op < cpy)
                                *op++ = *ref++;