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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id c1sm2672036pje.24.2020.03.26.20.50.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Mar 2020 20:50:48 -0700 (PDT) Date: Thu, 26 Mar 2020 20:50:47 -0700 From: Kees Cook To: Vlastimil Babka Cc: Luis Chamberlain , Iurii Zaikin , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-mm@kvack.org, Ivan Teterevkov , Michal Hocko , David Rientjes , Matthew Wilcox , "Eric W . Biederman" , "Guilherme G . Piccoli" Subject: Re: [RFC v3 1/2] kernel/sysctl: support setting sysctl parameters from kernel command line Message-ID: <202003262048.70D845CDF@keescook> References: <20200326181606.7027-1-vbabka@suse.cz> <202003261256.950F1E5@keescook> <8afebb97-db51-5744-dca9-840dc60cd396@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8afebb97-db51-5744-dca9-840dc60cd396@suse.cz> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 26, 2020 at 11:08:40PM +0100, Vlastimil Babka wrote: > On 3/26/20 9:24 PM, Kees Cook wrote: > I didn't want to modify param for the sake of error prints, but perhaps > the replacements won't confuse system admin too much? Ah, fair enough. Should be fine to do it against "path" then. Ignore that bit from me. ;) > >> + filp_close(file, NULL); > > > > Please check the return value of filp_close() and treat that as an error > > for this function too. > > Well I could print it, but not much else? The unmount will probably fail > in that case? Maybe? This is just a nit of mine from tracking horrible bugs that turned out to be unreported 'close' failures. :) > But I guess the "mount on first applicable argument" approach would work > with this scheme as well: > > struct vfsmount *proc_mnt = NULL; > parse_args(..., &proc_mnt, ...) Yes please! That would be perfect. (And yeah, it's a sensible optimization to do it "as needed"; I hadn't thought of that.) -- Kees Cook