From: Yonglong Liu liuyonglong@huawei.com
[ Upstream commit a06656211304fec653c1931c2ca6d644013b5bbb ]
Enable promisc mode of PF, set VF link state to enable, and run iperf of the VF, then do self test of the PF. The self test will fail with a low frequency, and may cause a use-after-free problem.
[ 87.142126] selftest:000004a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 87.159722] ================================================================== [ 87.174187] BUG: KASAN: use-after-free in hex_dump_to_buffer+0x140/0x608 [ 87.187600] Read of size 1 at addr ffff003b22828000 by task ethtool/1186 [ 87.201012] [ 87.203978] CPU: 7 PID: 1186 Comm: ethtool Not tainted 5.5.0-rc4-gfd51c473-dirty #4 [ 87.219306] Hardware name: Huawei TaiShan 2280 V2/BC82AMDA, BIOS TA BIOS 2280-A CS V2.B160.01 01/15/2020 [ 87.238292] Call trace: [ 87.243173] dump_backtrace+0x0/0x280 [ 87.250491] show_stack+0x24/0x30 [ 87.257114] dump_stack+0xe8/0x140 [ 87.263911] print_address_description.isra.8+0x70/0x380 [ 87.274538] __kasan_report+0x12c/0x230 [ 87.282203] kasan_report+0xc/0x18 [ 87.288999] __asan_load1+0x60/0x68 [ 87.295969] hex_dump_to_buffer+0x140/0x608 [ 87.304332] print_hex_dump+0x140/0x1e0 [ 87.312000] hns3_lb_check_skb_data+0x168/0x170 [ 87.321060] hns3_clean_rx_ring+0xa94/0xfe0 [ 87.329422] hns3_self_test+0x708/0x8c0
The length of packet sent by the selftest process is only 128 + 14 bytes, and the min buffer size of a BD is 256 bytes, and the receive process will make sure the packet sent by the selftest process is in the linear part, so only check the linear part in hns3_lb_check_skb_data().
So fix this use-after-free by using skb_headlen() to dump skb->data instead of skb->len.
Fixes: c39c4d98dc65 ("net: hns3: Add mac loopback selftest support in hns3 driver") Signed-off-by: Yonglong Liu liuyonglong@huawei.com Signed-off-by: Huazhong Tan tanhuazhong@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c index 0c34ea1223580..1cb6f95f3a946 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c @@ -151,18 +151,21 @@ static void hns3_lb_check_skb_data(struct hns3_enet_ring *ring, { struct hns3_enet_tqp_vector *tqp_vector = ring->tqp_vector; unsigned char *packet = skb->data; + u32 len = skb_headlen(skb); u32 i;
- for (i = 0; i < skb->len; i++) + len = min_t(u32, len, HNS3_NIC_LB_TEST_PACKET_SIZE); + + for (i = 0; i < len; i++) if (packet[i] != (unsigned char)(i & 0xff)) break;
/* The packet is correctly received */ - if (i == skb->len) + if (i == HNS3_NIC_LB_TEST_PACKET_SIZE) tqp_vector->rx_group.total_packets++; else print_hex_dump(KERN_ERR, "selftest:", DUMP_PREFIX_OFFSET, 16, 1, - skb->data, skb->len, true); + skb->data, len, true);
dev_kfree_skb_any(skb); }