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 1266834D937; Fri, 21 Nov 2025 13:37:39 +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=1763732259; cv=none; b=ViK4agfpy5pxrv5AhwKYtuAPM37lWfKfLpqMVCVuDSlUzuNuoZfnY3cgsY2aGhyzG7PB2fTTh15aWwfA343QrxQAZy1YX9xWale94F4zLdxru2V1Jii4AJnBVvHwzzkALWX0/yhqzx+vWuaBL0rzKbBi2+kIsPXtwqkYsoW4tm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763732259; c=relaxed/simple; bh=DaiYBVEGH7XYJxpcxQODYL1yCLc8/UlcpkH5cYrPgVI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=o+9k9TwJ04F0u4/f42POP6S2tyh/RzbH6E+EaxBPckAOvChhcyRdOsKJ002qyCrV84UTa/eJR53TP540nQ85hdEQXH6jibtBevOhZgknjTikg+wlxEWkAyxlM0Oadp/aAlLo32/9ANvf8hAX8dT8AcztTLyEuGWtYsgt3u94mbo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YxJNJImh; 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="YxJNJImh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89DA7C4CEFB; Fri, 21 Nov 2025 13:37:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763732258; bh=DaiYBVEGH7XYJxpcxQODYL1yCLc8/UlcpkH5cYrPgVI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YxJNJImhI3541CbyJpF0YE/IBliOmR51nV3Sp3ZbZxj2NADzw4Uw3mU7AmcHxmGLl iUzIGvtQTtUhUUd8Q8VUejeOCxHf1vWhHDNrTvXpl9mQTqw8FeGd+7Zd2N7sDD+O4g MomvYHFXpEyPGVHVQUeVrhksgHVkGKxX61ysGRno= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Owen Gu Subject: [PATCH 6.6 057/529] usb: gadget: f_fs: Fix epfile null pointer access after ep enable. Date: Fri, 21 Nov 2025 14:05:56 +0100 Message-ID: <20251121130233.047409994@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130230.985163914@linuxfoundation.org> References: <20251121130230.985163914@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 6.6-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 @@ -1941,7 +1941,12 @@ 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); @@ -1965,6 +1970,7 @@ static int ffs_func_eps_enable(struct ff } wake_up_interruptible(&ffs->wait); +done: spin_unlock_irqrestore(&func->ffs->eps_lock, flags); return ret;