From 910f3c2443bc9d902d3cb268cd88f268e7d9a45f Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Tue, 16 Sep 2025 15:27:50 +0100
Subject: [PATCH] io_uring/zcrx: check all niovs filled with dma addresses

[ Upstream commit d7ae46b454eb05e3df0d46c2ac9c61416a4d9057 ]

Add a warning if io_populate_area_dma() can't fill in all net_iovs, it
should never happen.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 io_uring/zcrx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index 2035c77a16357..23ffc95caa427 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -75,6 +75,9 @@ static int io_populate_area_dma(struct io_zcrx_ifq *ifq,
 			niov_idx++;
 		}
 	}
+
+	if (WARN_ON_ONCE(niov_idx != area->nia.num_niovs))
+		return -EFAULT;
 	return 0;
 }
 
-- 
2.47.3