On 8/17/23 14:22, 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 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 sidtab_str_cache.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
Cc: Stephen Smalley <stephen.smalley.work@xxxxxxxxx>
Cc: Eric Paris <eparis@xxxxxxxxxxxxxx>
Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Cc: selinux@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Thanks
--
Gustavo
---
security/selinux/ss/sidtab.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index d8ead463b8df..732fd8e22a12 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -25,7 +25,7 @@ struct sidtab_str_cache {
struct list_head lru_member;
struct sidtab_entry *parent;
u32 len;
- char str[];
+ char str[] __counted_by(len);
};
#define index_to_sid(index) ((index) + SECINITSID_NUM + 1)
