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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 6FEB3C433DF for ; Thu, 18 Jun 2020 08:30:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46673206E2 for ; Thu, 18 Jun 2020 08:30:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592469017; bh=erJJX+MUc0SAh2SFc+lXX11lR042jRpX4/uhzCfsfoY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=vEFVO+7sYaDzf6cFk20jC4Ozy6qIACnUkvPOuf9nllfGQd7G587nC5vsFS/HaLMld bo/K1e5ktjti62PqUx4u7JUQ2ks5truPnFKz/sq6PjFFQX09qeD6lGfRQCSGv8IJit U+xXDqMUfgkn/dO5JlTtIVMwJ2LuiaX6G7FdcbgI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728703AbgFRIaQ (ORCPT ); Thu, 18 Jun 2020 04:30:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:52576 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728507AbgFRIaM (ORCPT ); Thu, 18 Jun 2020 04:30:12 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4EF142100A; Thu, 18 Jun 2020 08:30:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592469008; bh=erJJX+MUc0SAh2SFc+lXX11lR042jRpX4/uhzCfsfoY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZT3UwOaTyJMiXqqCZHQk87OhQ7AIxHsdR6EIHjdRbF+AuWQgTdMcFGATZlZAKm6Oz RBeW1oDZ4A949dsrx2hVlwCZAkRY2pICnPpzIQ2Sqb24+bueXNcFvba6H8YaTtH9fH nfjRVF9Fh796xQ6BJD9FlH029PGTjxo74bJfpwG0= Date: Thu, 18 Jun 2020 10:30:01 +0200 From: Greg KH To: qiang.zhang@windriver.com Cc: balbi@kernel.org, stern@rowland.harvard.edu, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: gadget: function: printer: fix use-after-free in __lock_acquire Message-ID: <20200618083001.GB1058534@kroah.com> References: <20200605035652.10387-1-qiang.zhang@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200605035652.10387-1-qiang.zhang@windriver.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 05, 2020 at 11:56:52AM +0800, qiang.zhang@windriver.com wrote: > From: Zqiang > > Fix this by increase object reference count. > > BUG: KASAN: use-after-free in __lock_acquire+0x3fd4/0x4180 > kernel/locking/lockdep.c:3831 > Read of size 8 at addr ffff8880683b0018 by task syz-executor.0/3377 > > CPU: 1 PID: 3377 Comm: syz-executor.0 Not tainted 5.6.11 #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xce/0x128 lib/dump_stack.c:118 > print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374 > __kasan_report+0x131/0x1b0 mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:641 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 > __lock_acquire+0x3fd4/0x4180 kernel/locking/lockdep.c:3831 > lock_acquire+0x127/0x350 kernel/locking/lockdep.c:4488 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 > printer_ioctl+0x4a/0x110 drivers/usb/gadget/function/f_printer.c:723 > vfs_ioctl fs/ioctl.c:47 [inline] > ksys_ioctl+0xfb/0x130 fs/ioctl.c:763 > __do_sys_ioctl fs/ioctl.c:772 [inline] > __se_sys_ioctl fs/ioctl.c:770 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 > do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4531a9 > Code: ed 60 fc ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 > 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d > 01 f0 ff ff 0f 83 bb 60 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fd14ad72c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 00000000004531a9 > RDX: fffffffffffffff9 RSI: 000000000000009e RDI: 0000000000000003 > RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bbd61 > R13: 00000000004d0a98 R14: 00007fd14ad736d4 R15: 00000000ffffffff > > Allocated by task 2393: > save_stack+0x21/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > __kasan_kmalloc.constprop.3+0xa7/0xd0 mm/kasan/common.c:515 > kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 > kmem_cache_alloc_trace+0xfa/0x2d0 mm/slub.c:2813 > kmalloc include/linux/slab.h:555 [inline] > kzalloc include/linux/slab.h:669 [inline] > gprinter_alloc+0xa1/0x870 drivers/usb/gadget/function/f_printer.c:1416 > usb_get_function+0x58/0xc0 drivers/usb/gadget/functions.c:61 > config_usb_cfg_link+0x1ed/0x3e0 drivers/usb/gadget/configfs.c:444 > configfs_symlink+0x527/0x11d0 fs/configfs/symlink.c:202 > vfs_symlink+0x33d/0x5b0 fs/namei.c:4201 > do_symlinkat+0x11b/0x1d0 fs/namei.c:4228 > __do_sys_symlinkat fs/namei.c:4242 [inline] > __se_sys_symlinkat fs/namei.c:4239 [inline] > __x64_sys_symlinkat+0x73/0xb0 fs/namei.c:4239 > do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 3368: > save_stack+0x21/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > kasan_set_free_info mm/kasan/common.c:337 [inline] > __kasan_slab_free+0x135/0x190 mm/kasan/common.c:476 > kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 > slab_free_hook mm/slub.c:1444 [inline] > slab_free_freelist_hook mm/slub.c:1477 [inline] > slab_free mm/slub.c:3034 [inline] > kfree+0xf7/0x410 mm/slub.c:3995 > gprinter_free+0x49/0xd0 drivers/usb/gadget/function/f_printer.c:1353 > usb_put_function+0x38/0x50 drivers/usb/gadget/functions.c:87 > config_usb_cfg_unlink+0x2db/0x3b0 drivers/usb/gadget/configfs.c:485 > configfs_unlink+0x3b9/0x7f0 fs/configfs/symlink.c:250 > vfs_unlink+0x287/0x570 fs/namei.c:4073 > do_unlinkat+0x4f9/0x620 fs/namei.c:4137 > __do_sys_unlink fs/namei.c:4184 [inline] > __se_sys_unlink fs/namei.c:4182 [inline] > __x64_sys_unlink+0x42/0x50 fs/namei.c:4182 > do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8880683b0000 > which belongs to the cache kmalloc-1k of size 1024 > The buggy address is located 24 bytes inside of > 1024-byte region [ffff8880683b0000, ffff8880683b0400) > The buggy address belongs to the page: > page:ffffea0001a0ec00 refcount:1 mapcount:0 mapping:ffff88806c00e300 > index:0xffff8880683b1800 compound_mapcount: 0 > flags: 0x100000000010200(slab|head) > raw: 0100000000010200 0000000000000000 0000000600000001 ffff88806c00e300 > raw: ffff8880683b1800 000000008010000a 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Reported-by: Kyungtae Kim > Signed-off-by: Zqiang > --- > drivers/usb/gadget/function/f_printer.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c > index 9c7ed2539ff7..8ed1295d7e35 100644 > --- a/drivers/usb/gadget/function/f_printer.c > +++ b/drivers/usb/gadget/function/f_printer.c > @@ -31,6 +31,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -64,7 +65,7 @@ struct printer_dev { > struct usb_gadget *gadget; > s8 interface; > struct usb_ep *in_ep, *out_ep; > - > + struct kref kref; > struct list_head rx_reqs; /* List of free RX structs */ > struct list_head rx_reqs_active; /* List of Active RX xfers */ > struct list_head rx_buffers; /* List of completed xfers */ Isn't there already a reference count for this structure? Why not use that instead? If not, should this be done to all gadget drivers? What makes this one unique? thanks, greg k-h