From: Nick Terrell terrelln@fb.com
[ Upstream commit 77618db346455129424fadbbaec596a09feaf3bb ]
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 Signed-off-by: Sasha Levin sashal@kernel.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 2c8bbe3e4c148..f37b7aec088ec 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;