CVE-2022-49112

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

mt76: fix monitor mode crash with sdio driver

mt7921s driver may receive frames with fragment buffers. If there is a

CTS packet received in monitor mode, the payload is 10 bytes only and

need 6 bytes header padding after RXD buffer. However, only RXD in the

first linear buffer, if we pull buffer size RXD-size+6 bytes with

skb_pull(), that would trigger "BUG_ON(skb->len < skb->data_len)" in

__skb_pull().

To avoid the nonlinear buffer issue, enlarge the RXD size from 128 to

256 to make sure all MCU operation in linear buffer.

[ 52.007562] kernel BUG at include/linux/skbuff.h:2313!

[ 52.007578] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP

[ 52.007987] pc : skb_pull+0x48/0x4c

[ 52.008015] lr : mt7921_queue_rx_skb+0x494/0x890 [mt7921_common]

[ 52.008361] Call trace:

[ 52.008377] skb_pull+0x48/0x4c

[ 52.008400] mt76s_net_worker+0x134/0x1b0 [mt76_sdio 35339a92c6eb7d4bbcc806a1d22f56365565135c]

[ 52.0084

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References