CVE-2017-18222: Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119)
value: In the Linux kernel before 4.12, Hisilicon Network Subsystem (HNS) does not consider the ETH_SS_PRIV_FLAGS case when retrieving sset_count data, which allows local users to cause a denial of service (buffer overflow and memory corruption) or possibly have unspecified other impact, as demonstrated by incompatibility between hns_get_sset_count and ethtool_get_strings.
CWE description: The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
CVSS v3 base score: 7.8
Published: 2018-03-08T14:29Z
Repository: https://github.com/torvalds/linux
Language: C
Files changed: drivers/net/ethernet/hisilicon/hns/hns_dsaf_gmac.c, drivers/net/ethernet/hisilicon/hns/hns_dsaf_ppe.c, drivers/net/ethernet/hisilicon/hns/hns_dsaf_rcb.c, drivers/net/ethernet/hisilicon/hns/hns_dsaf_xgmac.c
Commit date: 2017-05-02 15:08:21 -0400
Commit message: net: hns: fix ethtool_get_strings overflow in hns driver

hns_get_sset_count() returns HNS_NET_STATS_CNT and the data space allocated
is not enough for ethtool_get_strings(), which will cause random memory
corruption.

When SLAB and DEBUG_SLAB are both enabled, memory corruptions like the
the following can be observed without this patch:
[   43.115200] Slab corruption (Not tainted): Acpi-ParseExt start=ffff801fb0b69030, len=80
[   43.115206] Redzone: 0x9f911029d006462/0x5f78745f31657070.
[   43.115208] Last user: [<5f7272655f746b70>](0x5f7272655f746b70)
[   43.115214] 010: 70 70 65 31 5f 74 78 5f 70 6b 74 00 6b 6b 6b 6b  ppe1_tx_pkt.kkkk
[   43.115217] 030: 70 70 65 31 5f 74 78 5f 70 6b 74 5f 6f 6b 00 6b  ppe1_tx_pkt_ok.k
[   43.115218] Next obj: start=ffff801fb0b69098, len=80
[   43.115220] Redzone: 0x706d655f6f666966/0x9f911029d74e35b.
[   43.115229] Last user: [<ffff0000084b11b0>](acpi_os_release_object+0x28/0x38)
[   43.115231] 000: 74 79 00 6b 6b 6b 6b 6b 70 70 65 31 5f 74 78 5f  ty.kkkkkppe1_tx_
[   43.115232] 010: 70 6b 74 5f 65 72 72 5f 63 73 75 6d 5f 66 61 69  pkt_err_csum_fai

Signed-off-by: Timmy Li <lixiaoping3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Diff: diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_gmac.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_gmac.c
index 74bd260ca02a88..86944bc3b273fd 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_gmac.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_gmac.c
@@ -664,11 +664,11 @@ static void hns_gmac_get_strings(u32 stringset, u8 *data)
 	}
 }
 
 static int hns_gmac_get_sset_count(int stringset)
 {
-	if (stringset == ETH_SS_STATS)
+	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
 		return ARRAY_SIZE(g_gmac_stats_string);
 
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_ppe.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_ppe.c
index 93e71e27401b4d..b62816c1574eb8 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_ppe.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_ppe.c
@@ -420,11 +420,11 @@ void hns_ppe_update_stats(struct hns_ppe_cb *ppe_cb)
 		+= dsaf_read_dev(ppe_cb, PPE_HIS_TX_PKT_CS_FAIL_CNT_REG);
 }
 
 int hns_ppe_get_sset_count(int stringset)
 {
-	if (stringset == ETH_SS_STATS)
+	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
 		return ETH_PPE_STATIC_NUM;
 	return 0;
 }
 
 int hns_ppe_get_regs_count(void)
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_rcb.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_rcb.c
index e2e28532e4dc2d..6f3570cfb50160 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_rcb.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_rcb.c
@@ -874,11 +874,11 @@ void hns_rcb_get_stats(struct hnae_queue *queue, u64 *data)
  *@stringset:ethtool cmd
  *return rcb ring string set count
  */
 int hns_rcb_get_ring_sset_count(int stringset)
 {
-	if (stringset == ETH_SS_STATS)
+	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
 		return HNS_RING_STATIC_REG_NUM;
 
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_xgmac.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_xgmac.c
index 37a2fc35148f7f..51e7e9f5af4992 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_xgmac.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_xgmac.c
@@ -779,11 +779,11 @@ static void hns_xgmac_get_strings(u32 stringset, u8 *data)
  *@stringset: type of values in data
  *return xgmac string set count
  */
 static int hns_xgmac_get_sset_count(int stringset)
 {
-	if (stringset == ETH_SS_STATS)
+	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
 		return ARRAY_SIZE(g_xgmac_stats_string);
 
 	return 0;
 }
 

Vulnerable code: 	if (stringset == ETH_SS_STATS)
	if (stringset == ETH_SS_STATS)
	if (stringset == ETH_SS_STATS)
	if (stringset == ETH_SS_STATS)
Fixed code: 	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)
	if (stringset == ETH_SS_STATS || stringset == ETH_SS_PRIV_FLAGS)