[PATCH net-next v3 1/2] keys, dns: drop unused upayload->data NUL terminator

[PATCH net-next v3 1/2] keys, dns: drop unused upayload->data NUL terminator

[Thorsten Blum]

->data includes an extra NUL terminator despite never being used as a C
string and only accessing ->datalen bytes. Remove the redundant NUL
terminator and allocate one byte less in dns_resolver_preparse().

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v3:
- Update commit message
- v2: https://lore.kernel.org/lkml/20260409225703.158552-4-thorsten.blum@linux.dev/

Changes in v2:
- No changes in patch 1/2
- v1: https://lore.kernel.org/lkml/20260406175810.1018681-3-thorsten.blum@linux.dev/
---
 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 net-next v3 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 bounds checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v3:
- Formatting only, do not split the declaration into two lines (Jarkko)
- v2: https://lore.kernel.org/lkml/20260409225703.158552-7-thorsten.blum@linux.dev/

Changes in v2:
- Use __aligned(8) as suggested by David
- v1: https://lore.kernel.org/lkml/20260409073711.57020-6-thorsten.blum@linux.dev/
---
 include/keys/user-type.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/keys/user-type.h b/include/keys/user-type.h
index 386c31432789..30de4f92a721 100644
--- a/include/keys/user-type.h
+++ b/include/keys/user-type.h
@@ -27,7 +27,7 @@
 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[] __aligned(8) __counted_by(datalen); /* actual data */
 };
 
 extern struct key_type key_type_user;