CVE-2026-93784: wifi: cfg80211: validate IEs in cfg80211_wext_siwgenie()

CVE-2026-93784: wifi: cfg80211: validate IEs in cfg80211_wext_siwgenie()

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

wifi: cfg80211: validate IEs in cfg80211_wext_siwgenie()

The KASAN allocation trace shows that a malformed IE buffer is
stored via SIOCSIWGENIE (cfg80211_wext_siwgenie()) without any
validation. The crash trace shows that a subsequent SIOCSIWESSID
triggers a connection attempt which calls cfg80211_sme_get_conn_ies()
to process the stored IE buffer, causing:

 - An out-of-bounds read in skip_ie() which reads ies[pos+1]
   (the length byte) past the end of the 1-byte buffer.

 - An integer underflow in the memcpy size argument when offs
   returned by ieee80211_ie_split() exceeds ies_len, causing
   unsigned subtraction to wrap to SIZE_MAX and triggering a
   fortify panic.

Fix this by validating the IE buffer in cfg80211_wext_siwgenie()
before storing it.

[drop unnecessary ie_len check, update commit message]

The Linux kernel CVE team has assigned CVE-2026-93784 to this issue.


Affected and fixed versions
===========================

	Fixed in 6.12.111 with commit c970879e03b23a27df42caf7ba506485a165fb96
	Fixed in 6.18.53 with commit 01cc395cecfaa73134d39fb9a401d9605d8bb2c5
	Fixed in 7.2 with commit a2f5286ca4f304d3fd469f01b96b518608912a5c

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-93784
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/wireless/wext-sme.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/c970879e03b23a27df42caf7ba506485a165fb96
	https://git.kernel.org/stable/c/01cc395cecfaa73134d39fb9a401d9605d8bb2c5
	https://git.kernel.org/stable/c/a2f5286ca4f304d3fd469f01b96b518608912a5c