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 6684053D0B6; Wed, 23 Sep 2026 14:53:39 +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=1790175220; cv=none; b=TfRRsAyzElGqb3VshBny6ZrdHcEJKPp3YVMsXPvr9IbEGVRgADBxu8eVr9AsmIsk5VqXv+7SwR6uLvM97lv6lWIGBplOMUbT7FAMgUPtjH0RUuMY/JIUL/YUxjpPJQsVSugnn6LExUtj30sIL26sWJmtQ0zxdLbzplTwkucR6w0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790175220; c=relaxed/simple; bh=KLVU39fvYTDNzapuVjQUH3tv8P9eR62P0EwR6S4ud+A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t9srXBdwDZxWmzxzTSOFPgSX4Uc8f2bCrkpxgTt2RwKAe9Cpmw54GhGmgX7YcaacFXrYhOTlnS3soeiAJToCfzyp+CT4AHfMHcHLCOiSWdnLpgmX3aHzdeylzesaxEG5vULEP5N5/e5wzzmAGqL09JB7Pwk6NtLCOQSYoFacGvc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LLYHwgXg; 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="LLYHwgXg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CA071F000FF; Wed, 23 Sep 2026 14:53:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790175219; bh=WjnnQ/CKiXiINDHArR5PfcwISZ11uqabM5su+fGlmM0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LLYHwgXg0HYVJELaiVnr8WrM41kmSj0Ug3hE3cs09EgfF2qnOz/xvUNKeggZJpeCu dFTS/ADzY7EKKRl4i7DZetUxaU2HOCo6RNYlaSXzMtMFmZB3j12wW22Y1zbbMTjND6 b7wmo6o+a5TKa9sIPMe9U1AFpVAcGcrllu5nT2aY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiangshan Yi , Arend van Spriel , Johannes Berg Subject: [PATCH 6.18 323/398] wifi: brcmsmac: fix UAF in brcms_free_timer() Date: Wed, 23 Sep 2026 16:06:37 +0200 Message-ID: <20260923140651.792751329@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiangshan Yi commit 1eeca1d5e0920fbdad6449768fd2d4364e714180 upstream. brcms_free_timer() calls brcms_del_timer() which uses the non-synchronous cancel_delayed_work() to cancel the timer's underlying delayed work. If the work callback (_brcms_timer) is already running, cancel_delayed_work() returns false without waiting, and brcms_free_timer() proceeds to kfree(t) while the callback still accesses t through container_of(). Add an explicit cancel_delayed_work_sync() after brcms_del_timer() to guarantee that any in-flight callback has completed before the timer structure is freed. Fixes: 5b435de0d786 ("net: wireless: add brcm80211 drivers") Cc: stable@vger.kernel.org Signed-off-by: Jiangshan Yi Acked-by: Arend van Spriel Link: https://patch.msgid.link/20260815121043.938414-1-yijiangshan@kylinos.cn Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/broadcom/brcm80211/brcmsmac/mac80211_if.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/mac80211_if.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/mac80211_if.c @@ -1571,6 +1571,10 @@ void brcms_free_timer(struct brcms_timer /* delete the timer in case it is active */ brcms_del_timer(t); + /* Ensure the callback has finished before freeing the timer + * structure, since brcms_del_timer() uses non-synchronous cancel. + */ + cancel_delayed_work_sync(&t->dly_wrk); if (wl->timers == t) { wl->timers = wl->timers->next;