Bug 2440669 (CVE-2025-71234)

Summary: CVE-2025-71234 kernel: wifi: rtl8xxxu: fix slab-out-of-bounds in rtl8xxxu_sta_add
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2026-02-18 16:03:42 UTC 
In the Linux kernel, the following vulnerability has been resolved:

wifi: rtl8xxxu: fix slab-out-of-bounds in rtl8xxxu_sta_add

The driver does not set hw->sta_data_size, which causes mac80211 to
allocate insufficient space for driver private station data in
__sta_info_alloc(). When rtl8xxxu_sta_add() accesses members of
struct rtl8xxxu_sta_info through sta->drv_priv, this results in a
slab-out-of-bounds write.

KASAN report on RISC-V (VisionFive 2) with RTL8192EU adapter:

  BUG: KASAN: slab-out-of-bounds in rtl8xxxu_sta_add+0x31c/0x346
  Write of size 8 at addr ffffffd6d3e9ae88 by task kworker/u16:0/12

Set hw->sta_data_size to sizeof(struct rtl8xxxu_sta_info) during
probe, similar to how hw->vif_data_size is configured. This ensures
mac80211 allocates sufficient space for the driver's per-station
private data.

Tested on StarFive VisionFive 2 v1.2A board.
Comment 1 Alexander B 2026-02-18 20:31:39 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026021805-CVE-2025-71234-3bb7@gregkh/T