From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: KASAN: use-after-free Read in dvb_usb_device_exit From: Oliver Neukum Message-Id: <1555326745.13626.10.camel@suse.com> Date: Mon, 15 Apr 2019 13:12:25 +0200 To: syzbot , andreyknvl@google.com, syzkaller-bugs@googlegroups.com, mchehab@kernel.org, corbet@lwn.net, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-usb@vger.kernel.org List-ID: T24gRnIsIDIwMTktMDQtMTIgYXQgMDQ6NDYgLTA3MDAsIHN5emJvdCB3cm90ZToKPiBIZWxsbywK PiAKPiBzeXpib3QgZm91bmQgdGhlIGZvbGxvd2luZyBjcmFzaCBvbjoKPiAKPiBIRUFEIGNvbW1p dDogICAgOWEzM2IzNjkgdXNiLWZ1enplcjogbWFpbiB1c2IgZ2FkZ2V0IGZ1enplciBkcml2ZXIK PiBnaXQgdHJlZTogICAgICAgaHR0cHM6Ly9naXRodWIuY29tL2dvb2dsZS9rYXNhbi90cmVlL3Vz Yi1mdXp6ZXIKPiBjb25zb2xlIG91dHB1dDogaHR0cHM6Ly9zeXprYWxsZXIuYXBwc3BvdC5jb20v eC9sb2cudHh0P3g9MTY0Mzk3NGIyMDAwMDAKPiBrZXJuZWwgY29uZmlnOiAgaHR0cHM6Ly9zeXpr YWxsZXIuYXBwc3BvdC5jb20veC8uY29uZmlnP3g9MjNlMzdmNTlkOTRkZGQxNQo+IGRhc2hib2Fy ZCBsaW5rOiBodHRwczovL3N5emthbGxlci5hcHBzcG90LmNvbS9idWc/ZXh0aWQ9MjZlYzQxZTlm Nzg4YjNlYmEzOTYKPiBjb21waWxlcjogICAgICAgZ2NjIChHQ0MpIDkuMC4wIDIwMTgxMjMxIChl eHBlcmltZW50YWwpCj4gc3l6IHJlcHJvOiAgICAgIGh0dHBzOi8vc3l6a2FsbGVyLmFwcHNwb3Qu Y29tL3gvcmVwcm8uc3l6P3g9MTJmNWVmYTcyMDAwMDAKPiBDIHJlcHJvZHVjZXI6ICAgaHR0cHM6 Ly9zeXprYWxsZXIuYXBwc3BvdC5jb20veC9yZXByby5jP3g9MTM5NWEwZjMyMDAwMDAKPiAKPiBJ TVBPUlRBTlQ6IGlmIHlvdSBmaXggdGhlIGJ1ZywgcGxlYXNlIGFkZCB0aGUgZm9sbG93aW5nIHRh ZyB0byB0aGUgY29tbWl0Ogo+IFJlcG9ydGVkLWJ5OiBzeXpib3QrMjZlYzQxZTlmNzg4YjNlYmEz OTZAc3l6a2FsbGVyLmFwcHNwb3RtYWlsLmNvbQo+IAo+IGR2Yi11c2I6IHNjaGVkdWxlIHJlbW90 ZSBxdWVyeSBpbnRlcnZhbCB0byAxNTAgbXNlY3MuCj4gZHcyMTAyOiBzdTMwMDBfcG93ZXJfY3Ry bDogMCwgaW5pdGlhbGl6ZWQgMQo+IGR2Yi11c2I6IFRlVmlpIFM0MjEgUENJIHN1Y2Nlc3NmdWxs eSBpbml0aWFsaXplZCBhbmQgY29ubmVjdGVkLgo+IHVzYiAxLTE6IFVTQiBkaXNjb25uZWN0LCBk ZXZpY2UgbnVtYmVyIDIKCkhpLAoKcHJvcG9zZWQgZml4LiBJZiBub2JvZHkgb2JqZWN0cywgSSB3 aWxsIHN1Ym1pdCBpdC4KCglSZWdhcmRzCgkJT2xpdmVyCgpGcm9tIGQ2MDk3ZDIwNWFjNjE3NDUz MzRiNzk2MzlkM2I4YjkxMGFlNjZjNzEgTW9uIFNlcCAxNyAwMDowMDowMCAyMDAxCkZyb206IE9s aXZlciBOZXVrdW0gPG9uZXVrdW1Ac3VzZS5jb20+CkRhdGU6IE1vbiwgMTUgQXByIDIwMTkgMTM6 MDY6MDEgKzAyMDAKU3ViamVjdDogW1BBVENIXSBkdmI6IHVzYjogZml4IHVzZSBhZnRlciBmcmVl IGluIGR2Yl91c2JfZGV2aWNlX2V4aXQKCmR2Yl91c2JfZGV2aWNlX2V4aXQoKSBmcmVlcyBhbmQg dXNlcyB0ZWggZGV2aWNlIG5hbWUgaW4gdGhhdCBvcmRlcgpGaXggYnkgc3RvcmluZyB0aGUgbmFt ZSBpbiBhIGJ1ZmZlciBiZWZvcmUgZnJlZWluZyBpdAoKU2lnbmVkLW9mZi1ieTogT2xpdmVyIE5l dWt1bSA8b25ldWt1bUBzdXNlLmNvbT4KUmVwb3J0ZWQtYnk6IHN5emJvdCsyNmVjNDFlOWY3ODhi M2ViYTM5NkBzeXprYWxsZXIuYXBwc3BvdG1haWwuY29tCi0tLQogZHJpdmVycy9tZWRpYS91c2Iv ZHZiLXVzYi9kdmItdXNiLWluaXQuYyB8IDcgKysrKysrLQogMSBmaWxlIGNoYW5nZWQsIDYgaW5z ZXJ0aW9ucygrKSwgMSBkZWxldGlvbigtKQoKZGlmZiAtLWdpdCBhL2RyaXZlcnMvbWVkaWEvdXNi L2R2Yi11c2IvZHZiLXVzYi1pbml0LmMgYi9kcml2ZXJzL21lZGlhL3VzYi9kdmItdXNiL2R2Yi11 c2ItaW5pdC5jCmluZGV4IDk5OTUxZTAyYTg4MC4uMmUxNjcwY2MzOTAzIDEwMDY0NAotLS0gYS9k cml2ZXJzL21lZGlhL3VzYi9kdmItdXNiL2R2Yi11c2ItaW5pdC5jCisrKyBiL2RyaXZlcnMvbWVk aWEvdXNiL2R2Yi11c2IvZHZiLXVzYi1pbml0LmMKQEAgLTI4OCwxMyArMjg4LDE4IEBAIHZvaWQg ZHZiX3VzYl9kZXZpY2VfZXhpdChzdHJ1Y3QgdXNiX2ludGVyZmFjZSAqaW50ZikKIHsKIAlzdHJ1 Y3QgZHZiX3VzYl9kZXZpY2UgKmQgPSB1c2JfZ2V0X2ludGZkYXRhKGludGYpOwogCWNvbnN0IGNo YXIgKm5hbWUgPSAiZ2VuZXJpYyBEVkItVVNCIG1vZHVsZSI7CisJY2hhciBpZGVudGlmaWVyWzQw XTsKIAogCXVzYl9zZXRfaW50ZmRhdGEoaW50ZiwgTlVMTCk7CiAJaWYgKGQgIT0gTlVMTCAmJiBk LT5kZXNjICE9IE5VTEwpIHsKIAkJbmFtZSA9IGQtPmRlc2MtPm5hbWU7CisJCW1lbWNweShpZGVu dGlmaWVyLCBuYW1lLCAzOSk7CisJCWlkZW50aWZpZXJbMzldID0gTlVMTDsKIAkJZHZiX3VzYl9l eGl0KGQpOworCX0gZWxzZSB7CisJCW1lbWNweShpZGVudGlmaWVyLCBuYW1lLCAzOSk7CiAJfQot CWluZm8oIiVzIHN1Y2Nlc3NmdWxseSBkZWluaXRpYWxpemVkIGFuZCBkaXNjb25uZWN0ZWQuIiwg bmFtZSk7CisJaW5mbygiJXMgc3VjY2Vzc2Z1bGx5IGRlaW5pdGlhbGl6ZWQgYW5kIGRpc2Nvbm5l Y3RlZC4iLCBpZGVudGlmaWVyKTsKIAogfQogRVhQT1JUX1NZTUJPTChkdmJfdXNiX2RldmljZV9l eGl0KTsK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39D21C282DA for ; Mon, 15 Apr 2019 11:12:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15B2820880 for ; Mon, 15 Apr 2019 11:12:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727311AbfDOLMk (ORCPT ); Mon, 15 Apr 2019 07:12:40 -0400 Received: from mx2.suse.de ([195.135.220.15]:42172 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726298AbfDOLMj (ORCPT ); Mon, 15 Apr 2019 07:12:39 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 00DD0B05E; Mon, 15 Apr 2019 11:12:37 +0000 (UTC) Message-ID: <1555326745.13626.10.camel@suse.com> Subject: Re: KASAN: use-after-free Read in dvb_usb_device_exit From: Oliver Neukum To: syzbot , andreyknvl@google.com, syzkaller-bugs@googlegroups.com, mchehab@kernel.org, corbet@lwn.net, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-usb@vger.kernel.org Date: Mon, 15 Apr 2019 13:12:25 +0200 In-Reply-To: <000000000000789d3d058653d9bb@google.com> References: <000000000000789d3d058653d9bb@google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Message-ID: <20190415111225.77bO4ccF1T_620IQZVA4dNb7oJruraKWqsrUeZFlVMU@z> On Fr, 2019-04-12 at 04:46 -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver > git tree: https://github.com/google/kasan/tree/usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=1643974b200000 > kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15 > dashboard link: https://syzkaller.appspot.com/bug?extid=26ec41e9f788b3eba396 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12f5efa7200000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1395a0f3200000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+26ec41e9f788b3eba396@syzkaller.appspotmail.com > > dvb-usb: schedule remote query interval to 150 msecs. > dw2102: su3000_power_ctrl: 0, initialized 1 > dvb-usb: TeVii S421 PCI successfully initialized and connected. > usb 1-1: USB disconnect, device number 2 Hi, proposed fix. If nobody objects, I will submit it. Regards Oliver >From d6097d205ac61745334b79639d3b8b910ae66c71 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Mon, 15 Apr 2019 13:06:01 +0200 Subject: [PATCH] dvb: usb: fix use after free in dvb_usb_device_exit dvb_usb_device_exit() frees and uses teh device name in that order Fix by storing the name in a buffer before freeing it Signed-off-by: Oliver Neukum Reported-by: syzbot+26ec41e9f788b3eba396@syzkaller.appspotmail.com --- drivers/media/usb/dvb-usb/dvb-usb-init.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c index 99951e02a880..2e1670cc3903 100644 --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c @@ -288,13 +288,18 @@ void dvb_usb_device_exit(struct usb_interface *intf) { struct dvb_usb_device *d = usb_get_intfdata(intf); const char *name = "generic DVB-USB module"; + char identifier[40]; usb_set_intfdata(intf, NULL); if (d != NULL && d->desc != NULL) { name = d->desc->name; + memcpy(identifier, name, 39); + identifier[39] = NULL; dvb_usb_exit(d); + } else { + memcpy(identifier, name, 39); } - info("%s successfully deinitialized and disconnected.", name); + info("%s successfully deinitialized and disconnected.", identifier); } EXPORT_SYMBOL(dvb_usb_device_exit); -- 2.16.4