Date: Sat, 26 May 2018 02:57:29 +0800 From: Marcelo Araujo <araujobsdport@gmail.com> To: Shawn Webb <shawn.webb@hardenedbsd.org> Cc: Brooks Davis <brooks@freebsd.org>, svn-src-head@freebsd.org, Eitan Adler <lists@eitanadler.com>, svn-src-all@freebsd.org, src-committers <src-committers@freebsd.org> Subject: Re: svn commit: r334199 - head/usr.sbin/bhyve Message-ID: <CAOfEmZicEBSHrrTDnfsLDMjTNc0tNKpDYKQUp9ftAn57f=asRQ@mail.gmail.com> In-Reply-To: <20180525183403.i3bt2npfc3fq2cgf@mutt-hbsd> References: <201805250207.w4P275Pf060725@repo.freebsd.org> <20180525151134.GB99063@spindle.one-eyed-alien.net> <CAOfEmZgV9yssn5v8ZpbkwL=rrifoD1Z=uRxe6a0KyM3mrXrSjQ@mail.gmail.com> <CAF6rxgm32%2B_XazDvbtyFChPigxVB0HQ30r3=CvN65ko=zHq0yA@mail.gmail.com> <CAOfEmZhS4RZPn6%2BqOcU56HUtUgGids79cS=fBKfuGjpBBQQm5g@mail.gmail.com> <20180525174424.GD99063@spindle.one-eyed-alien.net> <CAOfEmZhm3HPGU3r2nK9o3ry8%2BxpzaFRDCgw3qCKgy2CTOu3NaQ@mail.gmail.com> <20180525182139.GE99063@spindle.one-eyed-alien.net> <CAOfEmZiOPsDpzJ1citMhGvVFDFpQg1gY8-tNkj3XReYuFpDC1w@mail.gmail.com> <20180525183403.i3bt2npfc3fq2cgf@mutt-hbsd>
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Thanks Shawn, I think there are plenty of places to fix this case! Thanks for the extra work :D. 2018-05-26 2:34 GMT+08:00 Shawn Webb <shawn.webb@hardenedbsd.org>: > On Sat, May 26, 2018 at 02:26:33AM +0800, Marcelo Araujo wrote: > > 2018-05-26 2:21 GMT+08:00 Brooks Davis <brooks@freebsd.org>: > > > > > On Sat, May 26, 2018 at 01:56:28AM +0800, Marcelo Araujo wrote: > > > > 2018-05-26 1:44 GMT+08:00 Brooks Davis <brooks@freebsd.org>: > > > > > > > > > On Sat, May 26, 2018 at 01:21:33AM +0800, Marcelo Araujo wrote: > > > > > > On Sat, May 26, 2018, 1:11 AM Eitan Adler <lists@eitanadler.com> > > > wrote: > > > > > > > > > > > > > On 25 May 2018 at 08:23, Marcelo Araujo < > araujobsdport@gmail.com> > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > On Fri, May 25, 2018, 11:11 PM Brooks Davis < > brooks@freebsd.org> > > > > > wrote: > > > > > > > >> > > > > > > > >> On Fri, May 25, 2018 at 02:07:05AM +0000, Marcelo Araujo > wrote: > > > > > > > >> > Author: araujo > > > > > > > >> > Date: Fri May 25 02:07:05 2018 > > > > > > > >> > New Revision: 334199 > > > > > > > >> > URL: https://svnweb.freebsd.org/changeset/base/334199 > > > > > > > >> > > > > > > > > >> > Log: > > > > > > > >> > Fix a memory leak on topology_parse(). > > > > > > > >> > > > > > > > > >> > strdup(3) allocates memory for a copy of the string, > does > > > the > > > > > copy > > > > > > > and > > > > > > > >> > returns a pointer to it. If there is no sufficient > memory > > > NULL > > > > > is > > > > > > > >> > returned > > > > > > > >> > and the global errno is set to ENOMEM. > > > > > > > >> > We do a sanity check to see if it was possible to > allocate > > > > > enough > > > > > > > >> > memory. > > > > > > > >> > > > > > > > > >> > Also as we allocate memory, we need to free this memory > > > used. > > > > > Or it > > > > > > > >> > will > > > > > > > >> > going out of scope leaks the storage it points to. > > > > > > > >> > > > > > > > > >> > Reviewed by: rgrimes > > > > > > > >> > MFC after: 3 weeks. > > > > > > > >> > X-MFC: r332298 > > > > > > > >> > Sponsored by: iXsystems Inc. > > > > > > > >> > Differential Revision: > https://reviews.freebsd.org/ > > > D15550 > > > > > > > >> > > > > > > > > >> > Modified: > > > > > > > >> > head/usr.sbin/bhyve/bhyverun.c > > > > > > > >> > > > > > > > > >> > Modified: head/usr.sbin/bhyve/bhyverun.c > > > > > > > >> > > > > > > > > >> > > > > > > > > ============================================================ > > > > > ================== > > > > > > > >> > --- head/usr.sbin/bhyve/bhyverun.c Fri May 25 01:38:59 > 2018 > > > > > > > >> > (r334198) > > > > > > > >> > +++ head/usr.sbin/bhyve/bhyverun.c Fri May 25 02:07:05 > 2018 > > > > > > > >> > (r334199) > > > > > > > >> > @@ -193,6 +193,7 @@ topology_parse(const char *opt) > > > > > > > >> > c = 1, n = 1, s = 1, t = 1; > > > > > > > >> > ns = false, scts = false; > > > > > > > >> > str = strdup(opt); > > > > > > > >> > + assert(str != NULL); > > > > > > > >> > > > > > > > >> Using assert seems like an odd choice when you've already > added > > > a > > > > > > > >> failure path and the strsep will crash immediately if > assert is > > > > > elided. > > > > > > > > > > > > > > > > > > > > > > > > Just to make a better point, I had the same discussion about > > > > > assert(3) in > > > > > > > > another review, we don't do NDEBUG even for RELEASE. > > > > > > > > > > > > > > IMHO we only use assert for asserting things ought to never be > > > false > > > > > > > except in buggy code. Using assert for handling is poor > practice. > > > > > > > > > > > > > > > > > > > Again, in this case we are using it all over the place and we > must > > > > > replace > > > > > > it. Also we should document it in somewhere perhaps in the > assert(3) > > > > > > otherwise myself and others will keep using it. If you use find, > not > > > only > > > > > > myself is using it to check strdup! So what is the suggestion to > > > handle > > > > > > assert(3)? Deprecated it? > > > > > > > > > > Code that uses assert() in place of error handling is wrong and > should > > > > > be fixed. assert(condition) means that condition must never happen > > > > > and if it does a bug has occurred (or the programmers assumptions > are > > > > > wrong). In this case failure would not be due to a bug, but do to > > > > > resource exhaustion which is expected to be handled. > > > > > > > > > > > > > I agree with you! We have plenty of place that use strdup(3) without > > > check > > > > the errno ENOMEN return; so do you think would be better bypass a > errno > > > > ENOMEN without check it and have a crash, or better abort(3) using > > > > assert(3) in case we have no memory available to allocated the memory > > > for a > > > > copy of a string? > > > > > > The correct code here would be one of: > > > > > > str = strdup(opt); > > > if (str == NULL) > > > goto out; > > > > > > > No, it is not the correct code! If we go out and free(str) we have > nothing > > to free, because we even didn't allocated memory for str. > > Hey Marcelo, > > I've authored this commit, which fixes the issues Brooks brought up > (and with which I agree): > > https://github.com/HardenedBSD/hardenedBSD/commit/ > 9c05b8def2c33e3889430cc2f54be0402a257366 > > Thanks, > > -- > Shawn Webb > Cofounder and Security Engineer > HardenedBSD > > Tor-ified Signal: +1 443-546-8752 > Tor+XMPP+OTR: lattera@is.a.hacker.sx > GPG Key ID: 0x6A84658F52456EEE > GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE > -- -- Marcelo Araujo (__)araujo@FreeBSD.org \\\'',)http://www.FreeBSD.org <http://www.freebsd.org/>; \/ \ ^ Power To Server. .\. /_)
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