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: slab-out-of-bounds Read in hex_string From: Alan Stern Message-Id: Date: Mon, 29 Apr 2019 16:07:04 -0400 (EDT) To: syzbot Cc: andreyknvl@google.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, rafael@kernel.org, syzkaller-bugs@googlegroups.com List-ID: T24gTW9uLCAyOSBBcHIgMjAxOSwgc3l6Ym90IHdyb3RlOgoKPiBIZWxsbywKPiAKPiBzeXpib3Qg Zm91bmQgdGhlIGZvbGxvd2luZyBjcmFzaCBvbjoKPiAKPiBIRUFEIGNvbW1pdDogICAgNDMxNTFk NmMgdXNiLWZ1enplcjogbWFpbiB1c2IgZ2FkZ2V0IGZ1enplciBkcml2ZXIKPiBnaXQgdHJlZTog ICAgICAgaHR0cHM6Ly9naXRodWIuY29tL2dvb2dsZS9rYXNhbi90cmVlL3VzYi1mdXp6ZXIKPiBj b25zb2xlIG91dHB1dDogaHR0cHM6Ly9zeXprYWxsZXIuYXBwc3BvdC5jb20veC9sb2cudHh0P3g9 MTM5YWMzN2YyMDAwMDAKPiBrZXJuZWwgY29uZmlnOiAgaHR0cHM6Ly9zeXprYWxsZXIuYXBwc3Bv dC5jb20veC8uY29uZmlnP3g9NDE4M2VlZWY2NTBkMTIzNAo+IGRhc2hib2FyZCBsaW5rOiBodHRw czovL3N5emthbGxlci5hcHBzcG90LmNvbS9idWc/ZXh0aWQ9YTlmZWZkMThjN2IyNDBmMTljNTQK PiBjb21waWxlcjogICAgICAgZ2NjIChHQ0MpIDkuMC4wIDIwMTgxMjMxIChleHBlcmltZW50YWwp Cj4gc3l6IHJlcHJvOiAgICAgIGh0dHBzOi8vc3l6a2FsbGVyLmFwcHNwb3QuY29tL3gvcmVwcm8u c3l6P3g9MTdmM2IzMzhhMDAwMDAKPiAKPiBJTVBPUlRBTlQ6IGlmIHlvdSBmaXggdGhlIGJ1Zywg cGxlYXNlIGFkZCB0aGUgZm9sbG93aW5nIHRhZyB0byB0aGUgY29tbWl0Ogo+IFJlcG9ydGVkLWJ5 OiBzeXpib3QrYTlmZWZkMThjN2IyNDBmMTljNTRAc3l6a2FsbGVyLmFwcHNwb3RtYWlsLmNvbQo+ IAo+ID09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PQo+IEJVRzogS0FTQU46IHNsYWItb3V0LW9mLWJvdW5kcyBpbiBoZXhfc3Ry aW5nKzB4NDE4LzB4NGIwIGxpYi92c3ByaW50Zi5jOjk3NQo+IFJlYWQgb2Ygc2l6ZSAxIGF0IGFk ZHIgZmZmZjg4ODIxYTQxYmQzOCBieSB0YXNrIGt3b3JrZXIvMDoxLzEyCj4gCj4gQ1BVOiAwIFBJ RDogMTIgQ29tbToga3dvcmtlci8wOjEgTm90IHRhaW50ZWQgNS4xLjAtcmMzLTMxOTAwNC1nNDMx NTFkNiAjNgo+IEhhcmR3YXJlIG5hbWU6IEdvb2dsZSBHb29nbGUgQ29tcHV0ZSBFbmdpbmUvR29v Z2xlIENvbXB1dGUgRW5naW5lLCBCSU9TICAKPiBHb29nbGUgMDEvMDEvMjAxMQo+IFdvcmtxdWV1 ZTogdXNiX2h1Yl93cSBodWJfZXZlbnQKPiBDYWxsIFRyYWNlOgo+ICAgX19kdW1wX3N0YWNrIGxp Yi9kdW1wX3N0YWNrLmM6NzcgW2lubGluZV0KPiAgIGR1bXBfc3RhY2srMHhlOC8weDE2ZSBsaWIv ZHVtcF9zdGFjay5jOjExMwo+ICAgcHJpbnRfYWRkcmVzc19kZXNjcmlwdGlvbisweDZjLzB4MjM2 IG1tL2thc2FuL3JlcG9ydC5jOjE4Nwo+ICAga2FzYW5fcmVwb3J0LmNvbGQrMHgxYS8weDNjIG1t L2thc2FuL3JlcG9ydC5jOjMxNwo+ICAgaGV4X3N0cmluZysweDQxOC8weDRiMCBsaWIvdnNwcmlu dGYuYzo5NzUKPiAgIHBvaW50ZXIrMHg0NjAvMHg5MTAgbGliL3ZzcHJpbnRmLmM6MTk4NQo+ICAg dnNucHJpbnRmKzB4NWEwLzB4MTZiMCBsaWIvdnNwcmludGYuYzoyNDAwCj4gICBwb2ludGVyKzB4 NjBiLzB4OTEwIGxpYi92c3ByaW50Zi5jOjIwMzgKPiAgIHZzbnByaW50ZisweDVhMC8weDE2YjAg bGliL3ZzcHJpbnRmLmM6MjQwMAo+ICAgdnNjbnByaW50ZisweDI5LzB4ODAgbGliL3ZzcHJpbnRm LmM6MjQ5OQo+ICAgdnByaW50a19zdG9yZSsweDQ1LzB4NGIwIGtlcm5lbC9wcmludGsvcHJpbnRr LmM6MTkwMAo+ICAgdnByaW50a19lbWl0KzB4MjEwLzB4NWEwIGtlcm5lbC9wcmludGsvcHJpbnRr LmM6MTk1Nwo+ICAgZGV2X3ZwcmludGtfZW1pdCsweDUwZS8weDU1MyBkcml2ZXJzL2Jhc2UvY29y ZS5jOjMxODUKPiAgIGRldl9wcmludGtfZW1pdCsweGJmLzB4ZjYgZHJpdmVycy9iYXNlL2NvcmUu YzozMTk2Cj4gICBfX2Rldl9wcmludGsrMHgxZWQvMHgyMTUgZHJpdmVycy9iYXNlL2NvcmUuYzoz MjA4Cj4gICBfZGV2X2luZm8rMHhkYy8weDEwZSBkcml2ZXJzL2Jhc2UvY29yZS5jOjMyNTQKPiAg IGRsZmJfcGFyc2VfdmVuZG9yX2Rlc2NyaXB0b3IgZHJpdmVycy92aWRlby9mYmRldi91ZGxmYi5j OjE1MzIgW2lubGluZV0KCkFjY2Vzc2luZyBiZXlvbmQgdGhlIGVuZCBvZiB0aGUgZGVzY3JpcHRv ci4KCiNzeXogdGVzdDogaHR0cHM6Ly9naXRodWIuY29tL2dvb2dsZS9rYXNhbi5naXQgdXNiLWZ1 enplcgoKLS0tIGEvZHJpdmVycy92aWRlby9mYmRldi91ZGxmYi5jCisrKyBiL2RyaXZlcnMvdmlk ZW8vZmJkZXYvdWRsZmIuYwpAQCAtMTUxMSw2ICsxNTExLDcgQEAgc3RhdGljIGludCBkbGZiX3Bh cnNlX3ZlbmRvcl9kZXNjcmlwdG9yKAogCWNoYXIgKmJ1ZjsKIAljaGFyICpkZXNjX2VuZDsKIAlp bnQgdG90YWxfbGVuOworCWludCB3aWR0aDsKIAogCWJ1ZiA9IGt6YWxsb2MoTUFYX1ZFTkRPUl9E RVNDUklQVE9SX1NJWkUsIEdGUF9LRVJORUwpOwogCWlmICghYnVmKQpAQCAtMTUyOSw5ICsxNTMw LDEwIEBAIHN0YXRpYyBpbnQgZGxmYl9wYXJzZV92ZW5kb3JfZGVzY3JpcHRvcigKIAl9CiAKIAlp ZiAodG90YWxfbGVuID4gNSkgeworCQl3aWR0aCA9IG1pbih0b3RhbF9sZW4sIDExKTsKIAkJZGV2 X2luZm8oJmludGYtPmRldiwKLQkJCSAidmVuZG9yIGRlc2NyaXB0b3IgbGVuZ3RoOiAlZCBkYXRh OiAlMTFwaFxuIiwKLQkJCSB0b3RhbF9sZW4sIGRlc2MpOworCQkJICJ2ZW5kb3IgZGVzY3JpcHRv ciBsZW5ndGg6ICVkIGRhdGE6ICUqcGhcbiIsCisJCQkgdG90YWxfbGVuLCB3aWR0aCwgZGVzYyk7 CiAKIAkJaWYgKChkZXNjWzBdICE9IHRvdGFsX2xlbikgfHwgLyogZGVzY3JpcHRvciBsZW5ndGgg Ki8KIAkJICAgIChkZXNjWzFdICE9IDB4NWYpIHx8ICAgLyogdmVuZG9yIGRlc2NyaXB0b3IgdHlw ZSAqLwo= 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=-5.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 AA664C004C9 for ; Mon, 29 Apr 2019 20:07:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81AD12075E for ; Mon, 29 Apr 2019 20:07:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729296AbfD2UHF (ORCPT ); Mon, 29 Apr 2019 16:07:05 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:55044 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1728928AbfD2UHF (ORCPT ); Mon, 29 Apr 2019 16:07:05 -0400 Received: (qmail 8690 invoked by uid 2102); 29 Apr 2019 16:07:04 -0400 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 29 Apr 2019 16:07:04 -0400 Date: Mon, 29 Apr 2019 16:07:04 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: syzbot cc: andreyknvl@google.com, , , , , Subject: Re: KASAN: slab-out-of-bounds Read in hex_string In-Reply-To: <000000000000f69c3b0587aa1bc5@google.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Message-ID: <20190429200704._G_xtfLZdGbQi0FjYnBTwDojtAfwQczjuQQtuhFn6fo@z> On Mon, 29 Apr 2019, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 43151d6c 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=139ac37f200000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4183eeef650d1234 > dashboard link: https://syzkaller.appspot.com/bug?extid=a9fefd18c7b240f19c54 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17f3b338a00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+a9fefd18c7b240f19c54@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: slab-out-of-bounds in hex_string+0x418/0x4b0 lib/vsprintf.c:975 > Read of size 1 at addr ffff88821a41bd38 by task kworker/0:1/12 > > CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc3-319004-g43151d6 #6 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: usb_hub_wq hub_event > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xe8/0x16e lib/dump_stack.c:113 > print_address_description+0x6c/0x236 mm/kasan/report.c:187 > kasan_report.cold+0x1a/0x3c mm/kasan/report.c:317 > hex_string+0x418/0x4b0 lib/vsprintf.c:975 > pointer+0x460/0x910 lib/vsprintf.c:1985 > vsnprintf+0x5a0/0x16b0 lib/vsprintf.c:2400 > pointer+0x60b/0x910 lib/vsprintf.c:2038 > vsnprintf+0x5a0/0x16b0 lib/vsprintf.c:2400 > vscnprintf+0x29/0x80 lib/vsprintf.c:2499 > vprintk_store+0x45/0x4b0 kernel/printk/printk.c:1900 > vprintk_emit+0x210/0x5a0 kernel/printk/printk.c:1957 > dev_vprintk_emit+0x50e/0x553 drivers/base/core.c:3185 > dev_printk_emit+0xbf/0xf6 drivers/base/core.c:3196 > __dev_printk+0x1ed/0x215 drivers/base/core.c:3208 > _dev_info+0xdc/0x10e drivers/base/core.c:3254 > dlfb_parse_vendor_descriptor drivers/video/fbdev/udlfb.c:1532 [inline] Accessing beyond the end of the descriptor. #syz test: https://github.com/google/kasan.git usb-fuzzer --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -1511,6 +1511,7 @@ static int dlfb_parse_vendor_descriptor( char *buf; char *desc_end; int total_len; + int width; buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL); if (!buf) @@ -1529,9 +1530,10 @@ static int dlfb_parse_vendor_descriptor( } if (total_len > 5) { + width = min(total_len, 11); dev_info(&intf->dev, - "vendor descriptor length: %d data: %11ph\n", - total_len, desc); + "vendor descriptor length: %d data: %*ph\n", + total_len, width, desc); if ((desc[0] != total_len) || /* descriptor length */ (desc[1] != 0x5f) || /* vendor descriptor type */