From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BF4D42FAE for ; Sun, 1 Aug 2021 06:31:19 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id E32AF60F46; Sun, 1 Aug 2021 06:31:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627799479; bh=Hjk4mRvv4tZfmzufHhgGp+Gs+CqEJwXIrTWoRuq3fAo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j/zttzu26H9ajVZnIPfx40VcPQwq8gVE0MEMBYMhhDqyKQmSwj5qeJgdj5oP/vIsi agImCk1DOwgtV50eWbICFz1gtlcfehbDjrVpjvR1qTEmeK7/mzUTi2bVS+LA4a//NT OSzZiA1HN8XgYNWT24ZutqnsZRU5opPvxvr/TwOY= Date: Sun, 1 Aug 2021 08:31:17 +0200 From: Greg Kroah-Hartman To: Larry Finger Cc: LKML , linux-staging@lists.linux.dev Subject: Re: kernel BUG in new r8188eu Message-ID: References: <80042e9f-6811-38f3-010b-1c0951ba88db@lwfinger.net> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Jul 31, 2021 at 11:18:10AM -0500, Larry Finger wrote: > On 7/31/21 12:37 AM, Greg Kroah-Hartman wrote: > > Is this a new regression due to the recent cleanups, or something that > > has always been here? > > I suspect that it has been there forever. I was just doing the kinds of > things a user might do, and locked up my box. > > > As for the error, looks like someone is reading to an address that is > > in userspace without doing the proper copy_from_user() thing. Do you > > have a full traceback? > > BUG: unable to handle page fault for address: ffffeb020003b848 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: 0000 [#1] SMP PTI > CPU: 2 PID: 45 Comm: kworker/2:1 Tainted: G C O > 5.14.0-rc2-00157-g390c661543a8 #8 > Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.50 09/29/2014 > Workqueue: usb_hub_wq hub_event [usbcore] > RIP: 0010:kfree+0x68/0x2c0 > Code: 01 e5 0f 82 5f 02 00 00 48 b8 00 00 00 80 7f 77 00 00 48 01 c5 48 b8 > 00 00 00 00 00 ea ff ff 48 c1 ed 0c 48 c1 e5 06 48 01 c5 <48> 8b 45 0> > RSP: 0018:ffffc900001efa78 EFLAGS: 00010282 > RAX: ffffea0000000000 RBX: ffffc90000ee1028 RCX: 000000008010000d > RDX: 0000000000000000 RSI: ffffffffa149eddf RDI: ffffc90000ee1578 > RBP: ffffeb020003b840 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000000 R11: ffff888121c0e400 R12: ffffc90000ee1578 > R13: ffff888101fd0000 R14: ffff888101fd0030 R15: 0000000000000003 > FS: 0000000000000000(0000) GS:ffff888323280000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffeb020003b848 CR3: 000000000220a002 CR4: 00000000001706e0 > Call Trace: > ? kfree+0x25a/0x2c0 > rtw_free_mlme_priv_ie_data+0x15/0xf8 [r8188eu] > _rtw_free_mlme_priv+0xe/0x30 [r8188eu] > rtw_free_mlme_priv+0x1a/0x47 [r8188eu] > rtw_free_drv_sw+0x5c/0x1ae [r8188eu] > rtw_usb_if1_deinit+0x67/0xcd [r8188eu] > rtw_dev_remove+0x5a/0xf4 [r8188eu] > usb_unbind_interface+0x8a/0x270 [usbcore] > ? kernfs_find_ns+0x35/0xd0 > __device_release_driver+0x1a0/0x260 > device_release_driver+0x24/0x30 > bus_remove_device+0xd8/0x140 > device_del+0x18b/0x3e0 > ? kobject_cleanup+0x49/0x130 > usb_disable_device+0xd9/0x260 [usbcore] > usb_disconnect.cold+0x7b/0x201 [usbcore] > hub_port_connect+0x88/0x8d0 [usbcore] > ? kfree+0xe6/0x2c0 > hub_port_connect_change+0xb1/0x3a0 [usbcore] > port_event+0x5d4/0x720 [usbcore] > hub_event+0x1db/0x430 [usbcore] > process_one_work+0x1dd/0x3a0 > worker_thread+0x50/0x3f0 > ? rescuer_thread+0x390/0x390 > kthread+0x128/0x140 > ? set_kthread_struct+0x40/0x40 > ret_from_fork+0x22/0x30 > Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device ctr ccm > r8188eu(C) rfcomm rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs> > crypto_simd cryptd i915 i2c_algo_bit serio_raw ttm drm_kms_helper > syscopyarea sysfillrect sysimgblt fb_sys_fops drm xhci_pci ehci_pci xhci_hcd > > > CR2: ffffeb020003b848 > ---[ end trace f5f4e2b2680b5fd7 ]--- Hm, if you revert c7e88ecbe328 ("staging: r8188eu: remove rtw_buf_free() function"), does the crash go away? > The driver is allocating some buffers using kmalloc variants, and others > using vmalloc. I checked to see if there was confusion on which form of free > should be used, but this one is allocated with kmalloc and freed with kfree, > which should be OK. I am worried that my "remove the wrapper" logic got something wrong here, so if you could test the revert of that, I would appreciate it. I think I need to go buy one of these devices so I can test cleanups locally... thanks, greg k-h