CVE-2026-43495: net: wwan: t7xx: validate port_count against message length in t7xx_port_enum_msg_handler

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-21 · updated 2026-07-23
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: net: wwan: t7xx: validate port_count against message length in t7xx_port_enum_msg_handler t7xx_port_enum_msg_handler() uses the modem-supplied port_count field as a loop bound over port_msg->data[] without checking that the message buffer contains sufficient data. A modem sending port_count=65535 in a 12-byte buffer triggers a slab-out-of-bounds read of up to 262140 bytes. Add a sizeof(*port_msg) check before accessing the port message header fields to guard against undersized messages. Add a struct_size() check after extracting port_count and before the loop. In t7xx_parse_host_rt_data(), guard the rt_feature header read with a remaining-buffer check before accessing data_len, validate feat_data_len against the actual remaining buffer to prevent OOB reads and signed integer overflow on offset. Pass msg_len from both call sites: skb->len at the DPMAIF path after skb_pull(), and the validated feat_data_len at the handshake path.

Affected products

Linux kernel: from 5.19 before 6.1.176; from 6.2 before 6.6.140; from 6.7 before 6.12.88; from 6.13 before 6.18.30; from 6.19 before 7.0.7; 7.1-rc1, 7.1-rc2 — fixed in 6.1.176, 6.12.88, 6.18.30, 6.6.140, 7.0.7

How to fix

Upgrade to a fixed version: Linux kernel 6.1.176, 6.12.88, 6.18.30, 6.6.140. Check the vendor advisory for mitigations.

References

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