[PATCH RESEND net-next 1/2] keys, dns: drop unused upayload->data NUL terminator

[PATCH RESEND net-next 1/2] keys, dns: drop unused upayload->data NUL terminator

[Thorsten Blum]

In dns_resolver_preparse(), do not NUL-terminate ->data and allocate one
byte less. The NUL terminator is never used and only ->datalen bytes are
accessed.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Resending this because patch 2/2 didn't go to netdev@ (Jakub)
Cc: netdev@vger.kernel.org
---
 net/dns_resolver/dns_key.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index c3c8c3240ef9..451247864a63 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -203,7 +203,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 	kdebug("store result");
 	prep->quotalen = result_len;
 
-	upayload = kmalloc_flex(*upayload, data, result_len + 1);
+	upayload = kmalloc_flex(*upayload, data, result_len);
 	if (!upayload) {
 		kleave(" = -ENOMEM");
 		return -ENOMEM;
@@ -211,7 +211,6 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 
 	upayload->datalen = result_len;
 	memcpy(upayload->data, data, result_len);
-	upayload->data[result_len] = '\0';
 
 	prep->payload.data[dns_key_data] = upayload;
 	kleave(" = 0");

[PATCH RESEND net-next 2/2] KEYS: annotate struct user_key_payload with __counted_by

[Thorsten Blum]

Add the __counted_by() compiler attribute to the flexible array member
'data' to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Resending this because patch 2/2 didn't go to netdev@ (Jakub)
Cc: netdev@vger.kernel.org
---
 include/keys/user-type.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/keys/user-type.h b/include/keys/user-type.h
index 386c31432789..2305991f4fcd 100644
--- a/include/keys/user-type.h
+++ b/include/keys/user-type.h
@@ -27,7 +27,8 @@
 struct user_key_payload {
 	struct rcu_head	rcu;		/* RCU destructor */
 	unsigned short	datalen;	/* length of this data */
-	char		data[] __aligned(__alignof__(u64)); /* actual data */
+	char		data[]		/* actual data */
+			__aligned(__alignof__(u64)) __counted_by(datalen);
 };
 
 extern struct key_type key_type_user;

Re: [PATCH RESEND net-next 2/2] KEYS: annotate struct user_key_payload with __counted_by

[David Howells]

Thorsten Blum <thorsten.blum@linux.dev> wrote:

> +			__aligned(__alignof__(u64)) __counted_by(datalen);

Can that be __aligned(8)?

David

Re: [PATCH RESEND net-next 2/2] KEYS: annotate struct user_key_payload with __counted_by

[Thorsten Blum]

On Thu, Apr 09, 2026 at 06:37:13PM +0100, David Howells wrote:
> Thorsten Blum <thorsten.blum@linux.dev> wrote:
> 
> > +			__aligned(__alignof__(u64)) __counted_by(datalen);
> 
> Can that be __aligned(8)?

Sure, I can send a v2 with __aligned(8).