Re: [PATCH] fs/select: Annotate struct poll_list with __counted_by()

From: Gustavo A. R. Silva
Date: Thu Aug 08 2024 - 11:11:25 EST




On 08/08/24 09:00, Thorsten Blum wrote:
Add the __counted_by compiler attribute to the flexible array member
entries to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxxx>

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

Thanks
--
Gustavo

---
fs/select.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/select.c b/fs/select.c
index 9515c3fa1a03..1a4849e2afb9 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -840,7 +840,7 @@ SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg)
struct poll_list {
struct poll_list *next;
unsigned int len;
- struct pollfd entries[];
+ struct pollfd entries[] __counted_by(len);
};
#define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd))