From 77618db346455129424fadbbaec596a09feaf3bb Mon Sep 17 00:00:00 2001
From: Nick Terrell <terrelln@fb.com>
Date: Thu, 12 Oct 2023 12:55:34 -0700
Subject: [PATCH] zstd: Fix array-index-out-of-bounds UBSAN warning
Zstd used an array of length 1 to mean a flexible array for C89
compatibility. Switch to a C99 flexible array to fix the UBSAN warning.
Tested locally by booting the kernel and writing to and reading from a
BtrFS filesystem with zstd compression enabled. I was unable to reproduce
the issue before the fix, however it is a trivial change.
Link: https://lkml.kernel.org/r/20231012213428.1390905-1-nickrterrell@gmail.com
Reported-by: syzbot+1f2eb3e8cd123ffce499@syzkaller.appspotmail.com
Reported-by: Eric Biggers <ebiggers@kernel.org>
Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nick Terrell <terrelln@fb.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
lib/zstd/common/fse_decompress.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/zstd/common/fse_decompress.c b/lib/zstd/common/fse_decompress.c
index a0d06095be83d..8dcb8ca39767c 100644
--- a/lib/zstd/common/fse_decompress.c
+++ b/lib/zstd/common/fse_decompress.c
@@ -312,7 +312,7 @@ size_t FSE_decompress_wksp(void* dst, size_t dstCapacity, const void* cSrc, size
typedef struct {
short ncount[FSE_MAX_SYMBOL_VALUE + 1];
- FSE_DTable dtable[1]; /* Dynamically sized */
+ FSE_DTable dtable[]; /* Dynamically sized */
} FSE_DecompressWksp;
--
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