On 9/22/23 11:28, 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 ip_sf_socklist.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Thanks
--
Gustavo
---
include/linux/igmp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/igmp.h b/include/linux/igmp.h
index ebf4349a53af..5171231f70a8 100644
--- a/include/linux/igmp.h
+++ b/include/linux/igmp.h
@@ -39,7 +39,7 @@ struct ip_sf_socklist {
unsigned int sl_max;
unsigned int sl_count;
struct rcu_head rcu;
- __be32 sl_addr[];
+ __be32 sl_addr[] __counted_by(sl_max);
};
#define IP_SFBLOCK 10 /* allocate this many at once */
