| Message ID | YoUuy4iTjFAcSn03@kili (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | df98714e432abf5cbdac3e4c1a13f94c65ddb8d3 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] net: ethernet: SP7021: fix a use after free of skb->len | expand |
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
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!
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);
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(-)