From: Teng Qi starmiku1207184332@gmail.com

stable inclusion from stable-v5.10.84 commit 22519eff7df2d88adcc2568d86046ce1e2b52803 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S24Z CVE: CVE-2021-47548

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit a66998e0fbf213d47d02813b9679426129d0d114 ]

The if statement: if (port >= DSAF_GE_NUM) return;

limits the value of port less than DSAF_GE_NUM (i.e., 8). However, if the value of port is 6 or 7, an array overflow could occur: port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off;

because the length of dsaf_dev->mac_cb is DSAF_MAX_PORT_NUM (i.e., 6).

To fix this possible array overflow, we first check port and if it is greater than or equal to DSAF_MAX_PORT_NUM, the function returns.

Reported-by: TOTE Robot oslab@tsinghua.edu.cn Signed-off-by: Teng Qi starmiku1207184332@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Cheng Yu serein.chengyu@huawei.com --- drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c index 8791d4eb1985..13affb9ce0c3 100644 --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c @@ -422,6 +422,10 @@ static void hns_dsaf_ge_srst_by_port(struct dsaf_device *dsaf_dev, u32 port, return;

if (!HNS_DSAF_IS_DEBUG(dsaf_dev)) { + /* DSAF_MAX_PORT_NUM is 6, but DSAF_GE_NUM is 8. + We need check to prevent array overflow */ + if (port >= DSAF_MAX_PORT_NUM) + return; reg_val_1 = 0x1 << port; port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off; /* there is difference between V1 and V2 in register.*/