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[linux] Port libzstd UBSAN fix

dev
Nick Terrell 2017-06-19 15:48:30 -07:00
parent 55f9cd4942
commit a48e129d48
2 changed files with 14 additions and 4 deletions
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7
contrib/linux-kernel/lib/zstd/compress.c
View File

@ -1978,10 +1978,15 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx *ctx, const void *src, size_t src
break; /* nothing found : store previous solution */
}
/* NOTE:
* start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
* (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
* overflows the pointer, which is undefined behavior.
*/
/* catch up */
if (offset) {
while ((start > anchor) && (start > base + offset - ZSTD_REP_MOVE) &&
(start[-1] == start[-1 - offset + ZSTD_REP_MOVE])) /* only search for offset within prefix */
(start[-1] == (start-offset+ZSTD_REP_MOVE)[-1])) /* only search for offset within prefix */
{
start--;
matchLength++;

11
contrib/linux-kernel/zstd.diff
View File

@ -1599,10 +1599,10 @@ index 0000000..a826b99
+#endif /* BITSTREAM_H_MODULE */
diff --git a/lib/zstd/compress.c b/lib/zstd/compress.c
new file mode 100644
index 0000000..42236a3
index 0000000..1aff542
--- /dev/null
+++ b/lib/zstd/compress.c
@@ -0,0 +1,3463 @@
@@ -0,0 +1,3468 @@
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
@ -3583,10 +3583,15 @@ index 0000000..42236a3
+ break; /* nothing found : store previous solution */
+ }
+
+ /* NOTE:
+ * start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
+ * (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
+ * overflows the pointer, which is undefined behavior.
+ */
+ /* catch up */
+ if (offset) {
+ while ((start > anchor) && (start > base + offset - ZSTD_REP_MOVE) &&
+ (start[-1] == start[-1 - offset + ZSTD_REP_MOVE])) /* only search for offset within prefix */
+ (start[-1] == (start-offset+ZSTD_REP_MOVE)[-1])) /* only search for offset within prefix */
+ {
+ start--;
+ matchLength++;