FAILED: patch "[PATCH] octeon_ep_vf: add NULL check for napi_build_skb()" failed to apply to 7.0-stable tree

gregkh
2026-05-01T12:30:19Z

The patch below does not apply to the 7.0-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-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x dd66b42854705e4e4ee7f14d260f86c578bed3e3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050148-renounce-robin-688e@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From dd66b42854705e4e4ee7f14d260f86c578bed3e3 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Thu, 9 Apr 2026 19:40:09 +0100
Subject: [PATCH] octeon_ep_vf: add NULL check for napi_build_skb()

napi_build_skb() can return NULL on allocation failure. In
__octep_vf_oq_process_rx(), the result is used directly without a NULL
check in both the single-buffer and multi-fragment paths, leading to a
NULL pointer dereference.

Add NULL checks after both napi_build_skb() calls, properly advancing
descriptors and consuming remaining fragments on failure.

Fixes: 1cd3b407977c ("octeon_ep_vf: add Tx/Rx processing and interrupt support")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Link: https://patch.msgid.link/20260409184009.930359-3-devnexen@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c
index 7bd1b9b8d7f5..d98247408242 100644
--- a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c
+++ b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c
@@ -414,10 +414,15 @@ static int __octep_vf_oq_process_rx(struct octep_vf_device *oct,
data_offset = OCTEP_VF_OQ_RESP_HW_SIZE;
rx_ol_flags = 0;
}
- rx_bytes += buff_info->len;
-
if (buff_info->len <= oq->max_single_buffer_size) {
skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
+ if (!skb) {
+ oq->stats->alloc_failures++;
+ desc_used++;
+ read_idx = octep_vf_oq_next_idx(oq, read_idx);
+ continue;
+ }
+ rx_bytes += buff_info->len;
skb_reserve(skb, data_offset);
skb_put(skb, buff_info->len);
desc_used++;
@@ -427,6 +432,27 @@ static int __octep_vf_oq_process_rx(struct octep_vf_device *oct,
u16 data_len;

skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
+ if (!skb) {
+ oq->stats->alloc_failures++;
+ desc_used++;
+ read_idx = octep_vf_oq_next_idx(oq, read_idx);
+ data_len = buff_info->len - oq->max_single_buffer_size;
+ while (data_len) {
+ dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ buff_info = (struct octep_vf_rx_buffer *)
+ &oq->buff_info[read_idx];
+ buff_info->page = NULL;
+ if (data_len < oq->buffer_size)
+ data_len = 0;
+ else
+ data_len -= oq->buffer_size;
+ desc_used++;
+ read_idx = octep_vf_oq_next_idx(oq, read_idx);
+ }
+ continue;
+ }
+ rx_bytes += buff_info->len;
skb_reserve(skb, data_offset);
/* Head fragment includes response header(s);
* subsequent fragments contains only data.