Executive brief
A memory management vulnerability was identified in the Linux kernel's Wi-Fi networking stack. Specifically, certain error conditions during wireless data transmission could lead to memory leaks because the system failed to properly release data buffers. This could allow a local attacker to exhaust system memory, potentially leading to a system crash or other unstable behavior.
Technical details
A memory leak (CWE-401) exists in the mac80211 subsystem of the Linux kernel. The function ieee80211_tx_prepare_skb() failed to free the socket buffer (skb) when ieee80211_tx_prepare() returned a TX_DROP status, whereas other error paths within the same function correctly handled the release. This inconsistency led to memory exhaustion over time. The fix introduces kfree_skb() to the missing error path and removes redundant free calls in driver-specific callers (ath9k, mt76, mac80211_hwsim) to prevent double-free vulnerabilities. This is a local attack vector requiring low privileges.
Affected products
- Linux Linux Kernel 3.13.1 to 6.18.20, 6.19 to 6.19.10, 7.0-rc1 to 7.0-rc7
Timeline
- 2026-03-14: other: Patch authored by Felix Fietkau
- 2026-04-03: disclosed: CVE published
- 2026-04-23: advisory: NIST initial analysis completed
References
- https://git.kernel.org/stable/c/06e769dddcbeb3baf2ce346273b53dd61fdbecf4
- https://git.kernel.org/stable/c/3b4d27acafaeab478fd24f79ad6e593a892828b9
- https://git.kernel.org/stable/c/50f1b690b4868923fbd242298def2fb88662f108
- https://git.kernel.org/stable/c/5ef8ca1c164786da24169af155c1ca1ff1353cf8
- https://git.kernel.org/stable/c/905ef207d5ed99ca64adfe39fba9ac46e434327a
- https://git.kernel.org/stable/c/9a779d1f480e83720b5384adf165604e7ee226bd
- https://git.kernel.org/stable/c/d5ad6ab61cbd89afdb60881f6274f74328af3ee9