From nobody Mon Jun 8 12:16:09 2026 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [13.75.44.102]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A32B3340409 for ; Fri, 29 May 2026 08:18:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.75.44.102 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780042718; cv=none; b=VDI6RB3XJ7FZUSJIB3HEhjP6jX98IJrv1VHVTNhuQzxINAO+T7RwN8ow7xk9rB/FarPknIHwNy5/RC02cDbMMKU8H5Yldx7dTW1s0CAyl7ojFhM84xOr+GtimDO5uTd1KR+LNRgIu0mlLhqX0dKf/PVpYsIQs9+DQCwAGgl0i6Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780042718; c=relaxed/simple; bh=Gb8Vpr1P0cTJWmdIDFfP34ChLUY91ExMRsyiC2YQT5Q=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Zogb3wdtzzI6G8QqnwMjqT7FmDJbOUyV7iLmZX9VLJPDXq9N7G3ZXB22TQeQMNUhuyryBQRj/2QJu8AJqSqcHhvmOmBhm+lJNd1r/MPFZtmxt5X7ay9gMq38o2a6awcK2gvng8/kUeMWO41Y8Z+Mka3czJ+9h+Md2wfVvpWLNbs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mails.tsinghua.edu.cn; spf=pass smtp.mailfrom=mails.tsinghua.edu.cn; dkim=pass (1024-bit key) header.d=mails.tsinghua.edu.cn header.i=@mails.tsinghua.edu.cn header.b=SUxzMxo6; arc=none smtp.client-ip=13.75.44.102 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mails.tsinghua.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mails.tsinghua.edu.cn Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mails.tsinghua.edu.cn header.i=@mails.tsinghua.edu.cn header.b="SUxzMxo6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mails.tsinghua.edu.cn; s=dkim; h=Received:From:To:Cc:Subject: Date:Message-ID:MIME-Version:Content-Transfer-Encoding; bh=cgjP4 b1tWXzAyQSerqUgQowDPB6KIQASF8wVesagMRU=; b=SUxzMxo6Op5WA2HgOQv/V E6I9lGHlA3serSbTcwP6rHKsR3ipfG3I9AxWJ/uu50EpIBA0CI1/y852AgExD4Ww 40zv05zoo2GQ3r65li58bySl6lkva0skKbJOHHOV4vlyjGPZeU9DZNb2AwT/pxFg 4URoq5h1E8tfZ6/Cn93N0E= Received: from localhost.localdomain (unknown [211.102.241.99]) by web2 (Coremail) with SMTP id yQQGZQBnQprOSxlqX3bdAQ--.15689S2; Fri, 29 May 2026 16:18:22 +0800 (CST) From: Yizhou Zhao To: v9fs@lists.linux.dev Cc: Yizhou Zhao , Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Christian Schoenebeck , linux-kernel@vger.kernel.org, Yuxiang Yang , Ao Wang , Xuewei Feng , Qi Li , Ke Xu Subject: [PATCH] net/9p/usbg: Fix use-after-free in usb9pfs_free_func Date: Fri, 29 May 2026 16:18:16 +0800 Message-ID: <20260529081817.77898-1-zhaoyz24@mails.tsinghua.edu.cn> X-Mailer: git-send-email 2.46.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: yQQGZQBnQprOSxlqX3bdAQ--.15689S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw1DXFyrCF45XFyfGF43Awb_yoW8AFW8pF ZIkr4akF98Gr47Z34ktr4vv3WxCF4kAFyFgry0ka43uanxK3WxtF1vy3sY9rs8Aa9Fkryr tFZ0qryUAr1kCrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUP014x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1lnxkEFVAIw20F6cxK64vIFxWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xv F2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v26r1j6r 4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I 648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AFwI0_Jw0_GFylc2xSY4AK67 AK6r43MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAF wI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc4 0Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AK xVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr 1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbasjUUU UUU== X-CM-SenderInfo: 52kd05r2suqzpdlo2hxwvl0wxkxdhvlgxou0/1tbiAgECAWoZNcA8vAAAsG Content-Type: text/plain; charset="utf-8" In usb9pfs_free_func, kfree(usb9pfs) frees the entire f_usb9pfs structure which contains the embedded usb_function member that the parameter 'f' points to. After the kfree, the code accesses f->fi via container_of(f->fi, struct f_usb9pfs_opts, func_inst) and later calls usb_free_all_descriptors(f), both of which dereference the freed memory. Since f is &usb9pfs->function, all post-kfree accesses through f constitute use-after-free on the already-freed usb9pfs allocation. Move kfree(usb9pfs) to the end of the function so that all accesses through f complete before the memory is freed. Fixes: a3be076dc174 ("net/9p/usbg: Add new usb gadget function transport") Reported-by: Yizhou Zhao Reported-by: Yuxiang Yang Reported-by: Ao Wang Reported-by: Xuewei Feng Reported-by: Qi Li Reported-by: Ke Xu Assisted-by: GLM:GLM-5.1 Signed-off-by: Yizhou Zhao --- diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c index 1ce7033..c30ef5f 100644 --- a/net/9p/trans_usbg.c +++ b/net/9p/trans_usbg.c @@ -725,8 +725,6 @@ static void usb9pfs_free_func(struct usb_function *f) struct f_usb9pfs *usb9pfs =3D func_to_usb9pfs(f); struct f_usb9pfs_opts *opts; =20 - kfree(usb9pfs); - opts =3D container_of(f->fi, struct f_usb9pfs_opts, func_inst); =20 mutex_lock(&opts->lock); @@ -734,6 +732,8 @@ static void usb9pfs_free_func(struct usb_function *f) mutex_unlock(&opts->lock); =20 usb_free_all_descriptors(f); + + kfree(usb9pfs); } =20 static int usb9pfs_set_alt(struct usb_function *f, -- 2.43.0