From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E1BFF30C63C; Wed, 3 Dec 2025 15:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764775949; cv=none; b=fR2sbYe52xxVQwk+3oZol9btvrrULEheV9kcUFaAlidUZhDhFXhNKyfGYL7HNV7aixyKlDa+rnXB5pUvVKRruHwhAlzHrWDph01j9qdea9UdXdagtZKvjsj94jaXPqFMvogoRc5XnzIP4aUJm8ZpUCnFViF2jYVJ1wpcyBkUiwI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764775949; c=relaxed/simple; bh=fAGQXlmpLWqb5ZqqQI1XfT9e6TxiBJ2UUooE3ApT9/E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fPknsFOZ9Zvtd8AeYQ4ukdlXh3LFM595sqPA32eyxmCGbEEjJSXNn5kPsCmkoWrsBfeapJOufHM4oMW4cTYk6lDsiJkgGTQDdzwDIbsh13VaFTWCep1BRI67DqVpmT4XzG41/8zHqGFzzbdEsNmqNSv4ZjKxyz4sEb8Fe2cn6yY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=V6NxolbZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="V6NxolbZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 172C7C4CEF5; Wed, 3 Dec 2025 15:32:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764775948; bh=fAGQXlmpLWqb5ZqqQI1XfT9e6TxiBJ2UUooE3ApT9/E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V6NxolbZWFe0ZH1iaAYAXLeN+5ze3vgRcY5K5z5pDd5Q2FdcwAMYJ8Waf1MUW/QFy GLVbdP8gOXirz65L5V+QbYhiaEeqk+o98N3mpZcK+JShoNiXwWyUEZgdeXqmhsNY/x FRIWtM1Il7BcRkCudeFMIvUU/+NjelcmdK6VX8ps= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Owen Gu Subject: [PATCH 5.10 036/300] usb: gadget: f_fs: Fix epfile null pointer access after ep enable. Date: Wed, 3 Dec 2025 16:24:00 +0100 Message-ID: <20251203152401.805094251@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152400.447697997@linuxfoundation.org> References: <20251203152400.447697997@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Owen Gu commit cfd6f1a7b42f62523c96d9703ef32b0dbc495ba4 upstream. A race condition occurs when ffs_func_eps_enable() runs concurrently with ffs_data_reset(). The ffs_data_clear() called in ffs_data_reset() sets ffs->epfiles to NULL before resetting ffs->eps_count to 0, leading to a NULL pointer dereference when accessing epfile->ep in ffs_func_eps_enable() after successful usb_ep_enable(). The ffs->epfiles pointer is set to NULL in both ffs_data_clear() and ffs_data_close() functions, and its modification is protected by the spinlock ffs->eps_lock. And the whole ffs_func_eps_enable() function is also protected by ffs->eps_lock. Thus, add NULL pointer handling for ffs->epfiles in the ffs_func_eps_enable() function to fix issues Signed-off-by: Owen Gu Link: https://lore.kernel.org/r/20250915092907.17802-1-guhuinan@xiaomi.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_fs.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1993,7 +1993,12 @@ static int ffs_func_eps_enable(struct ff ep = func->eps; epfile = ffs->epfiles; count = ffs->eps_count; - while(count--) { + if (!epfile) { + ret = -ENOMEM; + goto done; + } + + while (count--) { ep->ep->driver_data = ep; ret = config_ep_by_speed(func->gadget, &func->function, ep->ep); @@ -2017,6 +2022,7 @@ static int ffs_func_eps_enable(struct ff } wake_up_interruptible(&ffs->wait); +done: spin_unlock_irqrestore(&func->ffs->eps_lock, flags); return ret;