diff mbox series

netem: Annotate struct disttable with __counted_by

Message ID 20231003231823.work.684-kees@kernel.org (mailing list archive)
State Mainlined
Commit 0fef0907d6faaab280d052e385d0da876182a1d2
Headers show
Series netem: Annotate struct disttable with __counted_by | expand

Commit Message

Kees Cook Oct. 3, 2023, 11:18 p.m. UTC
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 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 disttable.

Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/sched/sch_netem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Gustavo A. R. Silva Oct. 3, 2023, 11:38 p.m. UTC | #1
On 10/4/23 01:18, Kees Cook wrote:
> 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 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 disttable.
> 
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Cc: Cong Wang <xiyou.wangcong@gmail.com>
> Cc: Jiri Pirko <jiri@resnulli.us>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: netdev@vger.kernel.org
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
>   net/sched/sch_netem.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
> index 4ad39a4a3cf5..6ba2dc191ed9 100644
> --- a/net/sched/sch_netem.c
> +++ b/net/sched/sch_netem.c
> @@ -67,7 +67,7 @@
>   
>   struct disttable {
>   	u32  size;
> -	s16 table[];
> +	s16 table[] __counted_by(size);
>   };
>   
>   struct netem_sched_data {
Stephen Hemminger Oct. 4, 2023, 3:32 a.m. UTC | #2
On Tue,  3 Oct 2023 16:18:23 -0700
Kees Cook <keescook@chromium.org> wrote:

> 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 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 disttable.
> 
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Cc: Cong Wang <xiyou.wangcong@gmail.com>
> Cc: Jiri Pirko <jiri@resnulli.us>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: netdev@vger.kernel.org
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@chromium.org

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>

PS: size is intended wrong in original code but that is not important.
Should have lined up with table[].
patchwork-bot+netdevbpf@kernel.org Oct. 6, 2023, 1:40 a.m. UTC | #3
Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue,  3 Oct 2023 16:18:23 -0700 you wrote:
> 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 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 disttable.
> 
> [...]

Here is the summary with links:
  - netem: Annotate struct disttable with __counted_by
    https://git.kernel.org/netdev/net-next/c/0fef0907d6fa

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 4ad39a4a3cf5..6ba2dc191ed9 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -67,7 +67,7 @@ 
 
 struct disttable {
 	u32  size;
-	s16 table[];
+	s16 table[] __counted_by(size);
 };
 
 struct netem_sched_data {