CVE-2026-98052: net: bcmasp: clear txcb->last before writing each descriptor

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: net: bcmasp: clear txcb->last before writing each descriptor bcmasp_xmit() only wrote txcb->last = true for the final fragment of an SKB; non-final fragments left the field untouched. If a descriptor slot was reused while it still held a stale true from a previous SKB (possible when tx_spb_ring_full() underreported fullness), bcmasp_tx_reclaim() would see last == true mid-SKB and call dev_consume_skb_any() prematurely, freeing the sk_buff while its remaining fragments were still in flight. Unconditionally clear txcb->last before the conditional set so every descriptor slot starts from a known false state regardless of what a prior transmission left behind.

Affected products

Linux kernel: from 6.6 before 6.6.158; from 6.7 before 6.12.111; from 6.13 before 6.18.53; from 6.19 before 7.2.7; 7.3-rc1, 7.3-rc2 — fixed in 6.12.111, 6.18.53, 6.6.158, 7.2.7

How to fix

Upgrade to a fixed version: Linux kernel 6.12.111, 6.18.53, 6.6.158, 7.2.7. Check the vendor advisory for mitigations.

References

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