Bug 2507157 (CVE-2026-64446)

Summary: CVE-2026-64446 kernel: staging: rtl8723bs: fix heap buffer overflow in rtw_cfg80211_set_wpa_ie()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's rtl8723bs Wi-Fi driver. A local user can exploit this vulnerability by supplying a crafted Wi-Fi Protected Access (WPA) Information Element (IE) during a connection request. This can lead to a one-byte heap buffer overflow, potentially causing memory corruption and affecting system stability or leading to information disclosure.
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Description OSIDB Bzimport 2026-07-25 10:08:03 UTC
In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: fix heap buffer overflow in rtw_cfg80211_set_wpa_ie()

supplicant_ie is a 256-byte array in struct security_priv. The WPA and
WPA2 IE copy paths use:

    memcpy(padapter->securitypriv.supplicant_ie, &pwpa[0], wpa_ielen + 2);

where wpa_ielen is the raw IE length field (u8, 0-255). When a local user
supplies a connect request via nl80211 with a crafted WPA IE of length 255,
wpa_ielen + 2 equals 257, overflowing the 256-byte buffer by one byte into
the adjacent last_mic_err_time field.

rtw_parse_wpa_ie() does not prevent this: its length consistency check
compares *(wpa_ie+1) against (u8)(wpa_ie_len-2), which is (u8)(255) == 255
when wpa_ie_len = 257, so the check passes silently.

Add explicit bounds checks for both the WPA and WPA2 paths before the
memcpy, rejecting any IE whose total size (wpa_ielen + 2) exceeds the
supplicant_ie buffer.

Comment 1 Mauro Matteo Cascella 2026-08-02 13:35:25 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072540-CVE-2026-64446-f81d@gregkh/T