From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:43488 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750986AbdKSLtw (ORCPT ); Sun, 19 Nov 2017 06:49:52 -0500 Subject: Patch "usb: gadget: f_fs: Fix use-after-free in ffs_free_inst" has been added to the 4.13-stable tree To: andrew_gabbasov@mentor.com, felipe.balbi@linux.intel.com, gregkh@linuxfoundation.org Cc: , From: Date: Sun, 19 Nov 2017 12:49:50 +0100 Message-ID: <1511092190945@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled usb: gadget: f_fs: Fix use-after-free in ffs_free_inst to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-gadget-f_fs-fix-use-after-free-in-ffs_free_inst.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From cdafb6d8b8da7fde266f79b3287ac221aa841879 Mon Sep 17 00:00:00 2001 From: Andrew Gabbasov Date: Wed, 8 Nov 2017 10:13:15 -0700 Subject: usb: gadget: f_fs: Fix use-after-free in ffs_free_inst From: Andrew Gabbasov commit cdafb6d8b8da7fde266f79b3287ac221aa841879 upstream. KASAN enabled configuration reports an error BUG: KASAN: use-after-free in ffs_free_inst+... [usb_f_fs] at addr ... Write of size 8 by task ... This is observed after "ffs-test" is run and interrupted. If after that functionfs is unmounted and g_ffs module is unloaded, that use-after-free occurs during g_ffs module removal. Although the report indicates ffs_free_inst() function, the actual use-after-free condition occurs in _ffs_free_dev() function, which is probably inlined into ffs_free_inst(). This happens due to keeping the ffs_data reference in device structure during functionfs unmounting, while ffs_data itself is freed as no longer needed. The fix is to clear that reference in ffs_closed() function, which is a counterpart of ffs_ready(), where the reference is stored. Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Signed-off-by: Andrew Gabbasov Acked-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_fs.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -3669,6 +3669,7 @@ static void ffs_closed(struct ffs_data * goto done; ffs_obj->desc_ready = false; + ffs_obj->ffs_data = NULL; if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && ffs_obj->ffs_closed_callback) Patches currently in stable-queue which might be from andrew_gabbasov@mentor.com are queue-4.13/usb-gadget-f_fs-fix-use-after-free-in-ffs_free_inst.patch