2023-12-22 14:54:51

by Mark Brown

Subject: [PATCH v2] lsm: Add a __counted_by() annotation to lsm_ctx.ctx

The ctx in struct lsm_ctx is an array of size ctx_len, tell the compiler
about this using __counted_by() where supported to improve the ability to
detect overflow issues.

Reported-by: Aishwarya TCV <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
---
Changes in v2:
- Add explicit stddef.h inclusion in case __counted_by() definition
isn't otherwise pulled in.
- Link to v1: https://lore.kernel.org/r/[email protected]
---
include/uapi/linux/lsm.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h
index f0386880a78e..f8aef9ade549 100644
--- a/include/uapi/linux/lsm.h
+++ b/include/uapi/linux/lsm.h
@@ -9,6 +9,7 @@
#ifndef _UAPI_LINUX_LSM_H
#define _UAPI_LINUX_LSM_H

+#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/unistd.h>

@@ -36,7 +37,7 @@ struct lsm_ctx {
__u64 flags;
__u64 len;
__u64 ctx_len;
- __u8 ctx[];
+ __u8 ctx[] __counted_by(ctx_len);
};

/*

---
base-commit: ec4e9d630a64df500641892f4e259e8149594a99
change-id: 20231221-lsm-fix-counted-by-f9fd827e26aa

Best regards,
--
Mark Brown <[email protected]>

2023-12-22 23:00:54

by Paul Moore

Subject: Re: [PATCH v2] lsm: Add a __counted_by() annotation to lsm_ctx.ctx

On Dec 22, 2023 Mark Brown <[email protected]> wrote:
>
> The ctx in struct lsm_ctx is an array of size ctx_len, tell the compiler
> about this using __counted_by() where supported to improve the ability to
> detect overflow issues.
>
> Reported-by: Aishwarya TCV <[email protected]>
> Signed-off-by: Mark Brown <[email protected]>
> ---
> Changes in v2:
> - Add explicit stddef.h inclusion in case __counted_by() definition
> isn't otherwise pulled in.
> - Link to v1: https://lore.kernel.org/r/[email protected]
> ---
> include/uapi/linux/lsm.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

Applied to lsm/dev, thanks!

--
paul-moore.com