From: Kees Cook <keescook@chromium.org>
Date: Fri, 15 Sep 2023 20:14:14 +0000 (-0700)
Subject: aio: Annotate struct kioctx_table with __counted_by
X-Git-Tag: v6.6.17~3856^2~7
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=db7fcc884d8a1e8265a87306e728c3d3239b0ca2;p=platform%2Fkernel%2Flinux-rpi.git

aio: Annotate struct kioctx_table with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct kioctx_table.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: linux-aio@kvack.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Message-Id: <20230915201413.never.881-kees@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---

diff --git a/fs/aio.c b/fs/aio.c
index a4c2a6b..f8589ca 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -80,7 +80,7 @@ struct aio_ring {
 struct kioctx_table {
 	struct rcu_head		rcu;
 	unsigned		nr;
-	struct kioctx __rcu	*table[];
+	struct kioctx __rcu	*table[] __counted_by(nr);
 };
 
 struct kioctx_cpu {