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 A43E4343D7A; Wed, 3 Dec 2025 15:57:55 +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=1764777475; cv=none; b=WuvP4BNkW7QG7Jzux/YNPc3ihoCKXMo6NxM4Z8Hv8QKnUVF/SrTljX+s1NylYik4SzHA0DnrlNKhNGThSS37HtBzUpwWtMxUhQfi41rGzjOXpQ5oOO6bF+891pqwC83hn/AA2y9x6hJIi+cVCdsnp8PkJQ47cb6XAn1yQY7cdH4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764777475; c=relaxed/simple; bh=NNSOpLK0sTYwX5MWgoBawKCAIgwTzoxtP2Wh+o5ZOaE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tcG8hmfSqyvBE8APza+nmqXfjHNiRQ98bPZ6cIZ28dHXmbLeXBNPL+luH4FmJNRNn7BWeybJJJ98w6omrHSSoi0+cZS1Zkjg/YvVR/el/gqsA2rIUPoWT8Jn1MkMF4sG/WfI8LXvGfVXZCUq7Js1vJt+fDZ6J386U4tzkq0YysI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MUU9+kxo; 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="MUU9+kxo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2526FC4CEF5; Wed, 3 Dec 2025 15:57:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764777475; bh=NNSOpLK0sTYwX5MWgoBawKCAIgwTzoxtP2Wh+o5ZOaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MUU9+kxo03MJXIPlEAW3Jyxeu3kKtCe15JRNsBJsKdNyXBFfYOl5LlJ0OgRAVB5iS uP9cQauSag9B7I0oQ6Y36bQ2YE7fIuCxW6j06gUzAzT4HjEvTPxa/hLDt7j8Nx++R4 zUjTtxD3fAK7kRg9oFASB8xVnBa/hT5Iz7kDyhd0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Owen Gu Subject: [PATCH 5.15 049/392] usb: gadget: f_fs: Fix epfile null pointer access after ep enable. Date: Wed, 3 Dec 2025 16:23:19 +0100 Message-ID: <20251203152415.917545995@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152414.082328008@linuxfoundation.org> References: <20251203152414.082328008@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 5.15-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 @@ -2005,7 +2005,12 @@ 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); @@ -2029,6 +2034,7 @@ static int ffs_func_eps_enable(struct ff } wake_up_interruptible(&ffs->wait); +done: spin_unlock_irqrestore(&func->ffs->eps_lock, flags); return ret;