FAILED: patch "[PATCH] RDMA/mana: Remove user triggerable WARN_ON() in" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 159f2efabc89d3f931d38f2d35876535d4abf0a3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026051229-jelly-reverence-0bf5@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 159f2efabc89d3f931d38f2d35876535d4abf0a3 Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <[email protected]>
Date: Tue, 28 Apr 2026 13:17:38 -0300
Subject: [PATCH] RDMA/mana: Remove user triggerable WARN_ON() in
mana_ib_create_qp_rss()

Sashiko points out that the user can specify WQs sharing the same CQ as a part of the uAPI and this will trigger the WARN_ON() then go on to corrupt the kernel.

Just reject it outright and fail the QP creation.

index f4cbe21763bf..2d682428ef20 100644
@@ -137,8 +137,9 @@ int mana_ib_install_cq_cb(struct mana_ib_dev *mdev, struct mana_ib_cq *cq)
 
 	if (cq->queue.id >= gc->max_num_cqs)
 		return -EINVAL;
-	/* Create CQ table entry */
-	WARN_ON(gc->cq_table[cq->queue.id]);
+	/* Create CQ table entry, sharing a CQ between WQs is not supported */
+	if (gc->cq_table[cq->queue.id])
+		return -EINVAL;
 	if (cq->queue.kmem)
 		gdma_cq = cq->queue.kmem;
 	else

From: Jason Gunthorpe <[email protected]>

[ Upstream commit 159f2efabc89d3f931d38f2d35876535d4abf0a3 ]

Sashiko points out that the user can specify WQs sharing the same CQ as a part of the uAPI and this will trigger the WARN_ON() then go on to corrupt the kernel.

Just reject it outright and fail the QP creation.

---
 drivers/infiniband/hw/mana/cq.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

index f04a679d28714..54cf3868b2977 100644
@@ -120,8 +120,9 @@ int mana_ib_install_cq_cb(struct mana_ib_dev *mdev, struct mana_ib_cq *cq)
 
 	if (cq->queue.id >= gc->max_num_cqs)
 		return -EINVAL;
-	/* Create CQ table entry */
-	WARN_ON(gc->cq_table[cq->queue.id]);
+	/* Create CQ table entry, sharing a CQ between WQs is not supported */
+	if (gc->cq_table[cq->queue.id])
+		return -EINVAL;
 	gdma_cq = kzalloc(sizeof(*gdma_cq), GFP_KERNEL);
 	if (!gdma_cq)
 		return -ENOMEM;

2.53.0