[PATCH net-next v6 1/6] tls: Purge async_hold in tls_decrypt_async_wait()

[Chuck Lever <cel@kernel.org>]

From: Chuck Lever <chuck.lever@oracle.com>

The async_hold queue pins encrypted input skbs while
the AEAD engine references their scatterlist data. Once
tls_decrypt_async_wait() returns, every AEAD operation
has completed and the engine no longer references those
skbs, so they can be freed unconditionally.

A subsequent patch adds batch async decryption to
tls_sw_read_sock(), introducing a new call site that
must drain pending AEAD operations and release held
skbs. Move __skb_queue_purge(&ctx->async_hold) into
tls_decrypt_async_wait() so the purge is centralized
and every caller -- recvmsg's drain path, the -EBUSY
fallback in tls_do_decryption(), and the new read_sock
batch path -- releases held skbs on synchronization
without each site managing the purge independently.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/tls/tls_sw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index a656ce235758..20f8fc84c5f5 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -246,6 +246,7 @@ static int tls_decrypt_async_wait(struct tls_sw_context_rx *ctx)
 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
 	atomic_inc(&ctx->decrypt_pending);
 
+	__skb_queue_purge(&ctx->async_hold);
 	return ctx->async_wait.err;
 }
 
@@ -2224,7 +2225,6 @@ int tls_sw_recvmsg(struct sock *sk,
 
 		/* Wait for all previously submitted records to be decrypted */
 		ret = tls_decrypt_async_wait(ctx);
-		__skb_queue_purge(&ctx->async_hold);
 
 		if (ret) {
 			if (err >= 0 || err == -EINPROGRESS)

-- 
2.53.0