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" <da...@davemloft.net> Cc: Martin KaFai Lau <martin....@kernel.org> Cc: "Gustavo A. R. Silva" <gustavo...@kernel.org> Cc: Eric Dumazet <eduma...@google.com> Cc: Alexei Starovoitov <a...@kernel.org> Cc: Jakub Kicinski <k...@kernel.org> Signed-off-by: Kees Cook <keesc...@chromium.org> --- 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 */ -- 2.34.1
