[PATCH 5.16 197/285] qede: confirm skb is allocated before using

Greg Kroah-Hartman
2022-04-12T08:26:42Z

From: Jamie Bainbridge <jamie.bainbridge@gmail.com>

[ Upstream commit 4e910dbe36508654a896d5735b318c0b88172570 ]

qede_build_skb() assumes build_skb() always works and goes straight
to skb_reserve(). However, build_skb() can fail under memory pressure.
This results in a kernel panic because the skb to reserve is NULL.

Add a check in case build_skb() failed to allocate and return NULL.

The NULL return is handled correctly in callers to qede_build_skb().

Fixes: 8a8633978b842 ("qede: Add build_skb() support.")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/qlogic/qede/qede_fp.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qede/qede_fp.c b/drivers/net/ethernet/qlogic/qede/qede_fp.c
index 999abcfe3310..17f895250e04 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_fp.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_fp.c
@@ -747,6 +747,9 @@ qede_build_skb(struct qede_rx_queue *rxq,
buf = page_address(bd->data) + bd->page_offset;
skb = build_skb(buf, rxq->rx_buf_seg_size);

+ if (unlikely(!skb))
+ return NULL;
+
skb_reserve(skb, pad);
skb_put(skb, len);

--
2.35.1