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: usbip: vhc_hcd: prevent module being removed while device are attached From: Oliver Neukum Message-Id: <1522830330.30374.3.camel@suse.com> Date: Wed, 04 Apr 2018 10:25:30 +0200 To: Shuah Khan , Greg KH Cc: valentina.manea.m@gmail.com, shuah@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org List-ID: QW0gRGllbnN0YWcsIGRlbiAwMy4wNC4yMDE4LCAwOTo1NiAtMDYwMCBzY2hyaWViIFNodWFoIEto YW46Cj4gVGhpcyBpcyBhIHZpcnR1YWwgZGV2aWNlIGFzc29jaWF0ZWQgdG8gYSByZWFsIHBoeXNp Y2FsIGRldmljZSBvbiBhIGRpZmZlcmVudAo+IHN5c3RlbS4gTXkgY29uY2VybiBpcyB0aGF0IGlm IHRoZSBtb2R1bGUgZ2V0cyByZW1vdmVkIGFjY2lkZW50YWxseSB0aGVuIGl0Cj4gY291bGQgZGlz cnVwdCBhY2Nlc3MgdG8gdGhlIHJlbW90ZSBkZXZpY2UuIFRoZSByZW1vdGUgbmF0dXJlIG9mIHRo ZSBkZXZpY2UKPiB3aXRoIHNldmVyYWwgcGxheWVycyBpbnZvbHZlZCBtYWtlcyB0aGlzIHNjZW5h cmlvIGEgYml0IG1vcmUgY29tcGxleCB0aGFuCgpIaSwKCnlvdSB3b3VsZCBkb3VidGxlc3NseSBs b3NlIGNvbm5lY3Rpb24gdG8gdGhhdCBkZXZpY2UuIFlldCB5b3Ugd291bGQKYWxzbyBsb3NlIGNv bm5lY3Rpb25zIGlmIHlvdSBkb3duIHlvdXIgbmV0d29yay4gWW91IG5lZWQgdG8gYmUgcm9vdAp0 byB1bmxvYWQgYSBtb2R1bGUuIFlvdSBjb3VsZCBvdmVyd3JpdGUgeW91ciByb290IGZpbGVzeXN0 ZW1zIG9yIGZsYXNoCnlvdXIgZmlybXdhcmUuIEluIGdlbmVyYWwgd2UgY2Fubm90IGFuZCBkb24n dCB0cnkgdG8gcHJvdGVjdCByb290CmZyb20gc3VjaCBhY2NpZGVudHMuCgoJUmVnYXJkcwoJCU9s aXZlcgotLS0KVG8gdW5zdWJzY3JpYmUgZnJvbSB0aGlzIGxpc3Q6IHNlbmQgdGhlIGxpbmUgInVu c3Vic2NyaWJlIGxpbnV4LXVzYiIgaW4KdGhlIGJvZHkgb2YgYSBtZXNzYWdlIHRvIG1ham9yZG9t b0B2Z2VyLmtlcm5lbC5vcmcKTW9yZSBtYWpvcmRvbW8gaW5mbyBhdCAgaHR0cDovL3ZnZXIua2Vy bmVsLm9yZy9tYWpvcmRvbW8taW5mby5odG1sCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48mg/IZ4QYr//GiBIn/4JRa9WpAyqqzy6qfgiB9ArxZV+Gn1v1se9iUfKqop4ISQC8DXzut ARC-Seal: i=1; a=rsa-sha256; t=1522830696; cv=none; d=google.com; s=arc-20160816; b=uowX1sczFO25mpPgWbQEmp+7rF6UH1iAP1046Vo4QgeIcG+lS97VNiKWS7ODhBV+Vy X0Gbby2MD3LvNZ9XbcxfSauOAYOs40Q9NwxV+wbRGTMLmUel3ZHI1/0fToJ8IasfdeMZ ssd5ElWA+yxNwGtiZCsOftivu8sVHlaVO9c13/+4lj/p2gbOPPL6ijA6LzXg0pm1b10S C5xkI4xPCc0nPWddX0YMlnvdkzDmoAwwLqZ+PJ/TnsGayBA4vn0kIyOPpe6ZXGp8mhwz Ky+KcsVr2m5phGDQXYTd7NeKMC85sKml8/FNnbXnej3BBiNjv3rvU6Fl6+7V0qk4uJDP l6OA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to:date :cc:to:from:subject:message-id:arc-authentication-results; bh=tu/5a2I3SgdbZdk0jB+aSSkRwWX7c5uA5YIdib1RpTc=; b=RFmzKHGlSDvr5XyXw9W6k6ran6UB0zCO4mWN6rzSibRkD3oeMry2nGpdYCNKl/fTiG wIQl7HhYeJicFF2bc14DQsj55AV809YwT5PIp5LgduN5PS1e9u/zsD1NdxDT/wFpx+nt CiHK0wMeTYhF300dvDhYDOZTMb5vxqdT5v3W4+kQMekQDg2VmLKwYX7wMSzpdooFh0t0 bWLdZFVQEkK8Qbd1Tg6emCNni4hsMKLsyqeF4SHsXKsUJqDVnBJIyXXe0d072Zez6EHl csXZLaJgquEFM6FrCltpVqDoAMSZNa4q/5wiTaz9u2ZXd5itUR6mIXaDULMSdzceqjdQ gNCA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of oneukum@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=oneukum@suse.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of oneukum@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=oneukum@suse.com Message-ID: <1522830330.30374.3.camel@suse.com> Subject: Re: [PATCH] usbip: vhc_hcd: prevent module being removed while device are attached From: Oliver Neukum To: Shuah Khan , Greg KH Cc: valentina.manea.m@gmail.com, shuah@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Date: Wed, 04 Apr 2018 10:25:30 +0200 In-Reply-To: <6022b8f0-821a-2d1c-8032-4b298835feae@osg.samsung.com> References: <20180402205232.21659-1-shuahkh@osg.samsung.com> <20180403065618.GA1093@kroah.com> <6022b8f0-821a-2d1c-8032-4b298835feae@osg.samsung.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1596669167168287135?= X-GMAIL-MSGID: =?utf-8?q?1596803720246664305?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Am Dienstag, den 03.04.2018, 09:56 -0600 schrieb Shuah Khan: > This is a virtual device associated to a real physical device on a different > system. My concern is that if the module gets removed accidentally then it > could disrupt access to the remote device. The remote nature of the device > with several players involved makes this scenario a bit more complex than Hi, you would doubtlessly lose connection to that device. Yet you would also lose connections if you down your network. You need to be root to unload a module. You could overwrite your root filesystems or flash your firmware. In general we cannot and don't try to protect root from such accidents. Regards Oliver