From: Nick Terrell <[email protected]>
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.
Reported-by: [email protected]
Reported-by: Eric Biggers <[email protected]>
Reported-by: Kees Cook <[email protected]>
Signed-off-by: Nick Terrell <[email protected]>
---
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 a0d06095be83..8dcb8ca39767 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;
--
2.42.0
On Thu, Oct 12, 2023 at 02:34:28PM -0700, Nick Terrell wrote:
> From: Nick Terrell <[email protected]>
>
> 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.
>
> Reported-by: [email protected]
> Reported-by: Eric Biggers <[email protected]>
> Reported-by: Kees Cook <[email protected]>
> Signed-off-by: Nick Terrell <[email protected]>
Thanks! This 1-element conversion doesn't appear to need any sizeof()
related changes, so AFAICT this header change is sufficient.
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook