mainline inclusion from mainline-v5.16-rc5 commit 94cddf1e9227a171b27292509d59691819c458db category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S211 CVE: CVE-2021-47520

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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After calling netif_receive_skb(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is dereferenced just after the call netif_receive_skb(skb).

Reordering the lines solves the issue.

Fixes: b21d18b51b31 ("can: Topcliff: Add PCH_CAN driver.") Link: https://lore.kernel.org/all/20211123111654.621610-1-mailhol.vincent@wanadoo.... Cc: stable@vger.kernel.org Signed-off-by: Vincent Mailhol mailhol.vincent@wanadoo.fr Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de

Signed-off-by: Luo Gengkun luogengkun2@huawei.com --- drivers/net/can/pch_can.c | 2 +- drivers/net/can/pch_can.c.rej | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) create mode 100644 drivers/net/can/pch_can.c.rej

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c index c1317889d3d8..ced11ea89269 100644 --- a/drivers/net/can/pch_can.c +++ b/drivers/net/can/pch_can.c @@ -703,11 +703,11 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota) cf->data[i + 1] = data_reg >> 8; }

- netif_receive_skb(skb); rcv_pkts++; stats->rx_packets++; quota--; stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb);

pch_fifo_thresh(priv, obj_num); obj_num++; diff --git a/drivers/net/can/pch_can.c.rej b/drivers/net/can/pch_can.c.rej new file mode 100644 index 000000000000..229429bfb45c --- /dev/null +++ b/drivers/net/can/pch_can.c.rej @@ -0,0 +1,14 @@ +diff a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c (rejected hunks) +@@ -692,11 +692,11 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota) + cf->data[i + 1] = data_reg >> 8; + } + +- netif_receive_skb(skb); + rcv_pkts++; + stats->rx_packets++; + quota--; + stats->rx_bytes += cf->len; ++ netif_receive_skb(skb); + + pch_fifo_thresh(priv, obj_num); + obj_num++;