From 45605c75c52c7ae7bfe902214343aabcfe5ba0ff Mon Sep 17 00:00:00 2001
From: Wang Hai <wanghai38@huawei.com>
Date: Wed, 16 Nov 2022 01:24:07 +0800
Subject: [PATCH] e100: Fix possible use after free in e100_xmit_prepare
Git-commit: 45605c75c52c7ae7bfe902214343aabcfe5ba0ff
Patch-mainline: v6.1-rc8
References: git-fixes
In e100_xmit_prepare(), if we can't map the skb, then return -ENOMEM, so
e100_xmit_frame() will return NETDEV_TX_BUSY and the upper layer will
resend the skb. But the skb is already freed, which will cause UAF bug
when the upper layer resends the skb.
Remove the harmful free.
Fixes: 5e5d49422dfb ("e100: Release skb when DMA mapping is failed in e100_xmit_prepare")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/ethernet/intel/e100.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c
index 560d1d442232..d3fdc290937f 100644
--- a/drivers/net/ethernet/intel/e100.c
+++ b/drivers/net/ethernet/intel/e100.c
@@ -1741,11 +1741,8 @@ static int e100_xmit_prepare(struct nic *nic, struct cb *cb,
dma_addr = dma_map_single(&nic->pdev->dev, skb->data, skb->len,
DMA_TO_DEVICE);
/* If we can't map the skb, have the upper layer try later */
- if (dma_mapping_error(&nic->pdev->dev, dma_addr)) {
- dev_kfree_skb_any(skb);
- skb = NULL;
+ if (dma_mapping_error(&nic->pdev->dev, dma_addr))
return -ENOMEM;
- }
/*
* Use the last 4 bytes of the SKB payload packet as the CRC, used for
--
2.35.3