Author: allanjude
Date: Sun Sep 11 17:48:06 2016
New Revision: 305701
URL: https://svnweb.freebsd.org/changeset/base/305701
Log:
MFV r268120:
4936 lz4 could theoretically overflow a pointer with a certain input
illumos/illumos-gate@58d0718061c87e3d647c891ec5281b93c08dba4e
Reviewed by: delphij
MFC after: 2 weeks
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D7850
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/lz4.c
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/lz4.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/lz4.c Sun Sep 11
17:44:35 2016 (r305700)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/lz4.c Sun Sep 11
17:48:06 2016 (r305701)
@@ -187,21 +187,18 @@ lz4_decompress(void *s_start, void *d_st
defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || \
defined(__LP64__) || defined(_LP64))
#define LZ4_ARCH64 1
-/*
- * Illumos: On amd64 we have 20k of stack and 24k on sun4u and sun4v, so we
- * can spend 16k on the algorithm
- */
-/* FreeBSD: Use heap for all platforms for now */
-#define STACKLIMIT 0
#else
#define LZ4_ARCH64 0
+#endif
+
/*
- * Illumos: On i386 we only have 12k of stack, so in order to maintain the
- * same COMPRESSIONLEVEL we have to use heap allocation. Performance will
- * suck, but alas, it's ZFS on 32-bit we're talking about, so...
+ * Limits the amount of stack space that the algorithm may consume to hold
+ * the compression lookup table. The value `9' here means we'll never use
+ * more than 2k of stack (see above for a description of COMPRESSIONLEVEL).
+ * If more memory is needed, it is allocated from the heap.
*/
+/* FreeBSD: Use heap for all platforms for now */
#define STACKLIMIT 0
-#endif
/*
* Little Endian or Big Endian?
@@ -870,7 +867,7 @@ real_LZ4_compress(const char *source, ch
/* Decompression functions */
/*
- * Note: The decoding functionLZ4_uncompress_unknownOutputSize() is safe
+ * Note: The decoding function LZ4_uncompress_unknownOutputSize() is safe
* against "buffer overflow" attack type. They will never write nor
* read outside of the provided output buffers.
* LZ4_uncompress_unknownOutputSize() also insures that it will never
@@ -913,6 +910,9 @@ LZ4_uncompress_unknownOutputSize(const c
}
/* copy literals */
cpy = op + length;
+ /* CORNER-CASE: cpy might overflow. */
+ if (cpy < op)
+ goto _output_error; /* cpy was overflowed, bail! */
if ((cpy > oend - COPYLENGTH) ||
(ip + length > iend - COPYLENGTH)) {
if (cpy > oend)
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