crypto: zstd - Annotate struct zstd_ctx with __counted_by

Add the __counted_by() compiler attribute to the flexible array member
'wksp' to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Use struct_size(), which provides additional compile-time checks for
structures with flexible array members (e.g., __must_be_array()), for
the allocation size for a new 'zstd_ctx' while we're at it.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Thorsten Blum 2025-11-08 13:07:40 +01:00 committed by Herbert Xu
parent af3852cda3
commit 6cf3260755
1 changed files with 3 additions and 2 deletions

View File

@ -10,6 +10,7 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/overflow.h>
#include <linux/vmalloc.h>
#include <linux/zstd.h>
#include <crypto/internal/acompress.h>
@ -25,7 +26,7 @@ struct zstd_ctx {
zstd_dctx *dctx;
size_t wksp_size;
zstd_parameters params;
u8 wksp[] __aligned(8);
u8 wksp[] __aligned(8) __counted_by(wksp_size);
};
static DEFINE_MUTEX(zstd_stream_lock);
@ -44,7 +45,7 @@ static void *zstd_alloc_stream(void)
if (!wksp_size)
return ERR_PTR(-EINVAL);
ctx = kvmalloc(sizeof(*ctx) + wksp_size, GFP_KERNEL);
ctx = kvmalloc(struct_size(ctx, wksp, wksp_size), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);