Subject: [PATCH net-next v6 1/2] xsk: advance cq/fq check when shared umem is used

From: Jason Xing <[email-masked]>
Date: Sun, 4 Jan 2026 09:21:24 +0800

From: Jason Xing <[email-masked]>

In the shared umem mode with different queues or devices, either
uninitialized cq or fq is not allowed which was previously done in
xp_assign_dev_shared(). The patch advances the check at the beginning
so that 1) we can avoid a few memory allocation and stuff if cq or fq
is NULL, 2) it can be regarded as preparation for the next patch in
the series.

Signed-off-by: Jason Xing <[email-masked]>
---
 net/xdp/xsk.c           | 7 +++++++
 net/xdp/xsk_buff_pool.c | 4 ----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index f093c3453f64..3c52fafae47c 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -1349,6 +1349,13 @@ static int xsk_bind(struct socket *sock, struct sockaddr_unsized *addr, int addr
 		}
 
 		if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
+			/* One fill and completion ring required for each queue id. */
+			if (!xsk_validate_queues(xs)) {
+				err = -EINVAL;
+				sockfd_put(sock);
+				goto out_unlock;
+			}
+
 			/* Share the umem with another socket on another qid
 			 * and/or device.
 			 */
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 51526034c42a..6bf84316e2ad 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -247,10 +247,6 @@ int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 	u16 flags;
 	struct xdp_umem *umem = umem_xs->umem;
 
-	/* One fill and completion ring required for each queue id. */
-	if (!pool->fq || !pool->cq)
-		return -EINVAL;
-
 	flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
 	if (umem_xs->pool->uses_need_wakeup)
 		flags |= XDP_USE_NEED_WAKEUP;
-- 
2.41.3