From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 374C9526ABD; Wed, 23 Sep 2026 14:13:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790172802; cv=none; b=d8sZteLy5TZwKcUKGNjgBm6ylahgEsIDod9QrskfokVROGZq5faQS8l0Ron4NyOPhfia0Li6HHsn8pZGuqbG3NICxb6zGiXBQRGUtae4Vr0uhpP356JwLd4tusZh+ZcQhyjC5L/xrr8BUQ2rRpGU0RG1Ne+J9vxUE2cZ2KwMaMQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790172802; c=relaxed/simple; bh=dq7LShOowxdLbYtiVoZAORErGzWWkrVeP8WbbpfELtg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XTsmAFo0uwr/9jBlDwUJN/ntmphlt3AL2rNLiPM4xIaLhdJY/rfxrKQ4BabyvaYgWaDmFgsX2Ap+eLiuw2GePn346GE8eIgycGApUNYb6vQaDeKouLC9YC/8CLBNO4cTraY553g6IWGfYS8kTl6HDNBgn14PcpJuVQ8GiLfyXHY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HZMq9M5v; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HZMq9M5v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8577C1F000FF; Wed, 23 Sep 2026 14:13:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790172801; bh=AMZZ2fEyCb1ZVtVNkW5q7/+99rNLIDqmouyft3i/jkw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HZMq9M5vWe/kp+MiKU40pwPhO0DEzgOVF19E4HC5UxHyHOUvzWskEXKygBGRDtdDv VMGraohxNXqJfZy+grPrXEMGOtGMY/hTKUChf9Tyh/GBmuWGbA02HsRo6G9xMowdaA SeAkhc6DPrNJ8TrSDfZLwTbvt4SYTP4BbL9b3bds= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+1a797e1c81be78a2ace7@syzkaller.appspotmail.com, Johannes Berg , Sasha Levin Subject: [PATCH 7.2 065/438] wifi: cfg80211: only group hidden BSSes with beacon entries Date: Wed, 23 Sep 2026 16:01:26 +0200 Message-ID: <20260923140646.476690683@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140644.756254324@linuxfoundation.org> References: <20260923140644.756254324@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg [ Upstream commit 068843ed0902c552a13860c5ec6b2ca65b57a065 ] When a probe response for an unknown BSS comes in, __cfg80211_bss_update() looks for an existing entry with the same BSSID and a hidden (zero-length or NUL-filled) SSID, and if it finds one it groups them, using the beacon IEs from the existing entry. But that could find another entry without a beacon, if it was also from a probe response (with SSID), so there's a group without beacon elements. If a beacon with a hidden SSID for that BSSID arrives later, cfg80211_combine_bsses() goes looking for the probe response entries that belong to it - i.e. entries with the same BSSID and channel that have no beacon IEs - and finds those two. They are already grouped with each other, so it hits its WARN_ON_ONCE(bss->pub.hidden_beacon_bss) WARN_ON_ONCE(!list_empty(&bss->hidden_list)) which are there because an entry without beacon elements is not supposed to be part of a group yet. Only combine entries when a beacon was already received, ones that are kept separate will be combined when a beacon arrives. Assisted-by: LLM Fixes: 4593c4cbe1c9 ("cfg80211: fix BSS list hidden SSID lookup") Reported-by: syzbot+1a797e1c81be78a2ace7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1a797e1c81be78a2ace7 Link: https://patch.msgid.link/20260904165614.bcfa64715745.Iad740347c86de56d4ff4f96a95f3c3afc47c42de@changeid Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/wireless/scan.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 1a28f95246764..4f7d17e7f8337 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2049,6 +2049,13 @@ __cfg80211_bss_update(struct cfg80211_registered_device *rdev, if (!hidden) hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_NUL); + /* + * Only group with an entry with beacon data, otherwise + * beacon data can never be filled/updated. + */ + if (hidden && + !rcu_access_pointer(hidden->pub.beacon_ies)) + hidden = NULL; if (hidden) { new->pub.hidden_beacon_bss = &hidden->pub; list_add(&new->hidden_list, -- 2.53.0