* [PATCH net-next] net: ethernet: SP7021: fix a use after free of skb->len
@ 2022-05-18 17:37 Dan Carpenter
2022-05-19 14:23 ` 呂芳騰
2022-05-20 1:00 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Dan Carpenter @ 2022-05-18 17:37 UTC (permalink / raw)
To: Wells Lu
Cc: David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Andrew Lunn, netdev, kernel-janitors
The netif_receive_skb() function frees "skb" so store skb->len before
it is freed.
Fixes: fd3040b9394c ("net: ethernet: Add driver for Sunplus SP7021")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/net/ethernet/sunplus/spl2sw_int.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/sunplus/spl2sw_int.c b/drivers/net/ethernet/sunplus/spl2sw_int.c
index 69b1e2e0271e..a37c9a4c281f 100644
--- a/drivers/net/ethernet/sunplus/spl2sw_int.c
+++ b/drivers/net/ethernet/sunplus/spl2sw_int.c
@@ -29,6 +29,7 @@ int spl2sw_rx_poll(struct napi_struct *napi, int budget)
u32 mask;
int port;
u32 cmd;
+ u32 len;
/* Process high-priority queue and then low-priority queue. */
for (queue = 0; queue < RX_DESC_QUEUE_NUM; queue++) {
@@ -63,10 +64,11 @@ int spl2sw_rx_poll(struct napi_struct *napi, int budget)
skb_put(skb, pkg_len - 4); /* Minus FCS */
skb->ip_summed = CHECKSUM_NONE;
skb->protocol = eth_type_trans(skb, comm->ndev[port]);
+ len = skb->len;
netif_receive_skb(skb);
stats->rx_packets++;
- stats->rx_bytes += skb->len;
+ stats->rx_bytes += len;
/* Allocate a new skb for receiving. */
new_skb = netdev_alloc_skb(NULL, comm->rx_desc_buff_size);
--
2.35.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] net: ethernet: SP7021: fix a use after free of skb->len
2022-05-18 17:37 [PATCH net-next] net: ethernet: SP7021: fix a use after free of skb->len Dan Carpenter
@ 2022-05-19 14:23 ` 呂芳騰
2022-05-20 1:00 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: 呂芳騰 @ 2022-05-19 14:23 UTC (permalink / raw)
To: Dan Carpenter
Cc: David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Andrew Lunn, netdev, kernel-janitors
Hi Dan,
> The netif_receive_skb() function frees "skb" so store skb->len before
> it is freed.
>
> Fixes: fd3040b9394c ("net: ethernet: Add driver for Sunplus SP7021")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/net/ethernet/sunplus/spl2sw_int.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/sunplus/spl2sw_int.c b/drivers/net/ethernet/sunplus/spl2sw_int.c
> index 69b1e2e0271e..a37c9a4c281f 100644
> --- a/drivers/net/ethernet/sunplus/spl2sw_int.c
> +++ b/drivers/net/ethernet/sunplus/spl2sw_int.c
> @@ -29,6 +29,7 @@ int spl2sw_rx_poll(struct napi_struct *napi, int budget)
> u32 mask;
> int port;
> u32 cmd;
> + u32 len;
>
> /* Process high-priority queue and then low-priority queue. */
> for (queue = 0; queue < RX_DESC_QUEUE_NUM; queue++) {
> @@ -63,10 +64,11 @@ int spl2sw_rx_poll(struct napi_struct *napi, int budget)
> skb_put(skb, pkg_len - 4); /* Minus FCS */
> skb->ip_summed = CHECKSUM_NONE;
> skb->protocol = eth_type_trans(skb, comm->ndev[port]);
> + len = skb->len;
> netif_receive_skb(skb);
>
> stats->rx_packets++;
> - stats->rx_bytes += skb->len;
> + stats->rx_bytes += len;
>
> /* Allocate a new skb for receiving. */
> new_skb = netdev_alloc_skb(NULL, comm->rx_desc_buff_size);
> --
> 2.35.1
>
Thanks a lot for fixing the bug.
Can we just move the statement "stats->rx_bytes += skb->len;" to
before free skb?
For example,
skb_put(skb, pkg_len - 4); /* Minus FCS */
skb->ip_summed = CHECKSUM_NONE;
skb->protocol = eth_type_trans(skb, comm->ndev[port]);
stats->rx_packets++;
stats->rx_bytes += skb->len;
netif_receive_skb(skb);
/* Allocate a new skb for receiving. */
new_skb = netdev_alloc_skb(NULL, comm->rx_desc_buff_size);
Best regards,
Wells
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] net: ethernet: SP7021: fix a use after free of skb->len
2022-05-18 17:37 [PATCH net-next] net: ethernet: SP7021: fix a use after free of skb->len Dan Carpenter
2022-05-19 14:23 ` 呂芳騰
@ 2022-05-20 1:00 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-05-20 1:00 UTC (permalink / raw)
To: Dan Carpenter
Cc: wellslutw, davem, edumazet, kuba, pabeni, andrew, netdev,
kernel-janitors
Hello:
This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Wed, 18 May 2022 20:37:15 +0300 you wrote:
> The netif_receive_skb() function frees "skb" so store skb->len before
> it is freed.
>
> Fixes: fd3040b9394c ("net: ethernet: Add driver for Sunplus SP7021")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/net/ethernet/sunplus/spl2sw_int.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
Here is the summary with links:
- [net-next] net: ethernet: SP7021: fix a use after free of skb->len
https://git.kernel.org/netdev/net-next/c/df98714e432a
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
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2022-05-18 17:37 [PATCH net-next] net: ethernet: SP7021: fix a use after free of skb->len Dan Carpenter
2022-05-19 14:23 ` 呂芳騰
2022-05-20 1:00 ` patchwork-bot+netdevbpf
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