2023-07-14 12:09:27

by Polaris Pi

[permalink] [raw]
Subject: [PATCH v5] wifi: mwifiex: Fix OOB and integer underflow when rx packets

Make sure mwifiex_process_mgmt_packet and its callers
mwifiex_process_sta_rx_packet and mwifiex_process_uap_rx_packet
not out-of-bounds access the skb->data buffer.

Fixes: 2dbaf751b1de ("mwifiex: report received management frames to cfg80211")
Signed-off-by: Polaris Pi <[email protected]>
---
V5: Follow chromeos comments: preserve the original flow of mwifiex_process_uap_rx_packet
---
drivers/net/wireless/marvell/mwifiex/sta_rx.c | 3 ++-
drivers/net/wireless/marvell/mwifiex/uap_txrx.c | 11 +++++++++++
drivers/net/wireless/marvell/mwifiex/util.c | 5 +++++
3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/sta_rx.c b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
index 13659b02ba88..88aaec645291 100644
--- a/drivers/net/wireless/marvell/mwifiex/sta_rx.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
@@ -194,7 +194,8 @@ int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,

rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;

- if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
+ if ((rx_pkt_offset + rx_pkt_length) > (u16)skb->len ||
+ skb->len - rx_pkt_offset < sizeof(*rx_pkt_hdr)) {
mwifiex_dbg(adapter, ERROR,
"wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
skb->len, rx_pkt_offset, rx_pkt_length);
diff --git a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
index e495f7eaea03..32f4626a4d76 100644
--- a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
@@ -367,6 +367,17 @@ int mwifiex_process_uap_rx_packet(struct mwifiex_private *priv,
rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

+ if (le16_to_cpu(uap_rx_pd->rx_pkt_offset) > skb->len ||
+ skb->len - le16_to_cpu(uap_rx_pd->rx_pkt_offset) < sizeof(*rx_pkt_hdr)) {
+ mwifiex_dbg(adapter, ERROR,
+ "wrong rx packet offset: len=%d, offset=%d\n",
+ skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset));
+ priv->stats.rx_dropped++;
+
+ dev_kfree_skb_any(skb);
+ return 0;
+ }
+
ether_addr_copy(ta, rx_pkt_hdr->eth803_hdr.h_source);

if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
diff --git a/drivers/net/wireless/marvell/mwifiex/util.c b/drivers/net/wireless/marvell/mwifiex/util.c
index 94c2d219835d..31e1a82883e4 100644
--- a/drivers/net/wireless/marvell/mwifiex/util.c
+++ b/drivers/net/wireless/marvell/mwifiex/util.c
@@ -399,6 +399,11 @@ mwifiex_process_mgmt_packet(struct mwifiex_private *priv,

pkt_len = le16_to_cpu(rx_pd->rx_pkt_length);

+ if (pkt_len < sizeof(struct ieee80211_hdr) || skb->len < pkt_len) {
+ mwifiex_dbg(priv->adapter, ERROR, "invalid rx_pkt_length");
+ return -1;
+ }
+
ieee_hdr = (void *)skb->data;
if (ieee80211_is_mgmt(ieee_hdr->frame_control)) {
if (mwifiex_parse_mgmt_packet(priv, (u8 *)ieee_hdr,
--
2.25.1



2023-07-14 22:29:16

by Matthew Wang

[permalink] [raw]
Subject: Re: [PATCH v5] wifi: mwifiex: Fix OOB and integer underflow when rx packets

On Fri, Jul 14, 2023 at 2:02 PM Polaris Pi <[email protected]> wrote:
>
> Make sure mwifiex_process_mgmt_packet and its callers
> mwifiex_process_sta_rx_packet and mwifiex_process_uap_rx_packet
> not out-of-bounds access the skb->data buffer.
>
> Fixes: 2dbaf751b1de ("mwifiex: report received management frames to cfg80211")
> Signed-off-by: Polaris Pi <[email protected]>
> ---
> V5: Follow chromeos comments: preserve the original flow of mwifiex_process_uap_rx_packet
> ---
> drivers/net/wireless/marvell/mwifiex/sta_rx.c | 3 ++-
> drivers/net/wireless/marvell/mwifiex/uap_txrx.c | 11 +++++++++++
> drivers/net/wireless/marvell/mwifiex/util.c | 5 +++++
> 3 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/sta_rx.c b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> index 13659b02ba88..88aaec645291 100644
> --- a/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> +++ b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> @@ -194,7 +194,8 @@ int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
>
> rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;
>
> - if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
> + if ((rx_pkt_offset + rx_pkt_length) > (u16)skb->len ||
> + skb->len - rx_pkt_offset < sizeof(*rx_pkt_hdr)) {
> mwifiex_dbg(adapter, ERROR,
> "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
> skb->len, rx_pkt_offset, rx_pkt_length);
> diff --git a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
> index e495f7eaea03..32f4626a4d76 100644
> --- a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
> +++ b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
> @@ -367,6 +367,17 @@ int mwifiex_process_uap_rx_packet(struct mwifiex_private *priv,
> rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
> rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
>
> + if (le16_to_cpu(uap_rx_pd->rx_pkt_offset) > skb->len ||
> + skb->len - le16_to_cpu(uap_rx_pd->rx_pkt_offset) < sizeof(*rx_pkt_hdr)) {

The second condition is strictly a subset of the first. Can we just make this:

le16_to_cpu(uap_rx_pd->rx_pkt_offset) + sizeof(*rx_pkt_hdr) > skb->len

> + mwifiex_dbg(adapter, ERROR,
> + "wrong rx packet offset: len=%d, offset=%d\n",
> + skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset));
> + priv->stats.rx_dropped++;
> +
> + dev_kfree_skb_any(skb);
> + return 0;
> + }
> +
> ether_addr_copy(ta, rx_pkt_hdr->eth803_hdr.h_source);
>
> if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
> diff --git a/drivers/net/wireless/marvell/mwifiex/util.c b/drivers/net/wireless/marvell/mwifiex/util.c
> index 94c2d219835d..31e1a82883e4 100644
> --- a/drivers/net/wireless/marvell/mwifiex/util.c
> +++ b/drivers/net/wireless/marvell/mwifiex/util.c
> @@ -399,6 +399,11 @@ mwifiex_process_mgmt_packet(struct mwifiex_private *priv,
>
> pkt_len = le16_to_cpu(rx_pd->rx_pkt_length);
>
> + if (pkt_len < sizeof(struct ieee80211_hdr) || skb->len < pkt_len) {
> + mwifiex_dbg(priv->adapter, ERROR, "invalid rx_pkt_length");
> + return -1;
> + }
> +
> ieee_hdr = (void *)skb->data;
> if (ieee80211_is_mgmt(ieee_hdr->frame_control)) {
> if (mwifiex_parse_mgmt_packet(priv, (u8 *)ieee_hdr,
> --
> 2.25.1
>

2023-07-14 22:46:08

by Polaris Pi

[permalink] [raw]
Subject: Re: [PATCH v5] wifi: mwifiex: Fix OOB and integer underflow when rx packets

> formatting issue, space after (u16)
Delete space is required by checkpatch.pl

> why return -1 instead of returning appropriate error code , may be EMSGSIZE
Because of all other error paths return -1, follow original return code

Thanks

2023-07-17 14:02:15

by David Laight

[permalink] [raw]
Subject: RE: [PATCH v5] wifi: mwifiex: Fix OOB and integer underflow when rx packets

From: Polaris Pi
> Sent: 14 July 2023 13:02
>
> Make sure mwifiex_process_mgmt_packet and its callers
> mwifiex_process_sta_rx_packet and mwifiex_process_uap_rx_packet
> not out-of-bounds access the skb->data buffer.
>
...
> diff --git a/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> index 13659b02ba88..88aaec645291 100644
> --- a/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> +++ b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
> @@ -194,7 +194,8 @@ int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
>
> rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;
>
> - if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
> + if ((rx_pkt_offset + rx_pkt_length) > (u16)skb->len ||
> + skb->len - rx_pkt_offset < sizeof(*rx_pkt_hdr)) {

What is the (u16) cast for?
The domain of both tx_pkt_offset and rx_pkt_length is 16bits.
Their sum is of type 'int', masking skb->len to 16 bits just
discards high bits (which are probably zero).

The second test should probably be:
rx_pkt_offset + sizeof(*rx_pkt_hdr) > skb->len
although the first test includes the 'offset > len' check.

David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)