Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751352AbbLZEGh (ORCPT ); Fri, 25 Dec 2015 23:06:37 -0500 Received: from mga04.intel.com ([192.55.52.120]:53107 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750947AbbLZEGf (ORCPT ); Fri, 25 Dec 2015 23:06:35 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,480,1444719600"; d="scan'208";a="881129716" From: changbin.du@intel.com To: balbi@ti.com, gregkh@linuxfoundation.org Cc: r.baldyga@samsung.com, nab@linux-iscsi.org, andrzej.p@samsung.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Du, Changbin" Subject: [PATCH] usb: gadget: acm: set notify_req to NULL after freed to avoid double free Date: Sat, 26 Dec 2015 11:57:40 +0800 Message-Id: <1451102260-13204-1-git-send-email-changbin.du@intel.com> X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1747 Lines: 56 From: "Du, Changbin" If acm_bind fails before allocate notification and acm->notify_req is not set to NULL after freed last time, double free will happen. kernel BUG at mm/slub.c:3392! invalid opcode: 0000 [#1] PREEMPT SMP EIP is at kfree+0x172/0x180 Call Trace: [<80c0e3b6>] ? usb_ep_autoconfig_ss+0x86/0x170 [<80c13345>] gs_free_req+0x15/0x30 [<80c12df1>] acm_bind+0x1c1/0x2d0 [<80c0e9be>] usb_add_function+0x6e/0x120 [<80c213cb>] acm_function_bind_config+0x2b/0x90 Signed-off-by: Du, Changbin --- drivers/usb/gadget/function/f_acm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_acm.c b/drivers/usb/gadget/function/f_acm.c index 2fa1e80..e10c8d4 100644 --- a/drivers/usb/gadget/function/f_acm.c +++ b/drivers/usb/gadget/function/f_acm.c @@ -699,8 +699,10 @@ acm_bind(struct usb_configuration *c, struct usb_function *f) return 0; fail: - if (acm->notify_req) + if (acm->notify_req) { gs_free_req(acm->notify, acm->notify_req); + acm->notify_req = NULL; + } ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status); @@ -713,8 +715,10 @@ static void acm_unbind(struct usb_configuration *c, struct usb_function *f) acm_string_defs[0].id = 0; usb_free_all_descriptors(f); - if (acm->notify_req) + if (acm->notify_req) { gs_free_req(acm->notify, acm->notify_req); + acm->notify_req = NULL; + } } static void acm_free_func(struct usb_function *f) -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/