FAILED: patch "[PATCH] RDMA/irdma: Fix kernel stack leak in irdma_create_user_ah()" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-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 <stable@vger.kernel.org>.

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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 74586c6da9ea222a61c98394f2fc0a604748438c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026030901-book-commodity-3938@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 74586c6da9ea222a61c98394f2fc0a604748438c Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@ziepe.ca>
Date: Mon, 16 Feb 2026 11:02:49 -0400
Subject: [PATCH] RDMA/irdma: Fix kernel stack leak in irdma_create_user_ah()

struct irdma_create_ah_resp {  // 8 bytes, no padding
    __u32 ah_id;               // offset 0 - SET (uresp.ah_id = ah->sc_ah.ah_info.ah_idx)
    __u8  rsvd[4];             // offset 4 - NEVER SET <- LEAK
};

rsvd[4]: 4 bytes of stack memory leaked unconditionally. Only ah_id is assigned before ib_respond_udata().

The reserved members of the structure were not zeroed.

Cc: stable@vger.kernel.org
Fixes: b48c24c2d710 ("RDMA/irdma: Implement device supported verb APIs")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://patch.msgid.link/3-v1-83e918d69e73+a9-rdma_udata_rc_jgg@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/irdma/verbs.c b/drivers/infiniband/hw/irdma/verbs.c
index 15af53237217..7251cd7a2147 100644
--- a/drivers/infiniband/hw/irdma/verbs.c
+++ b/drivers/infiniband/hw/irdma/verbs.c
@@ -5212,7 +5212,7 @@ static int irdma_create_user_ah(struct ib_ah *ibah,
 #define IRDMA_CREATE_AH_MIN_RESP_LEN offsetofend(struct irdma_create_ah_resp, rsvd)
 	struct irdma_ah *ah = container_of(ibah, struct irdma_ah, ibah);
 	struct irdma_device *iwdev = to_iwdev(ibah->pd->device);
-	struct irdma_create_ah_resp uresp;
+	struct irdma_create_ah_resp uresp = {};
 	struct irdma_ah *parent_ah;
 	int err;