netdev - Re: [PATCH iproute2] mptcp: avoid uninitialised errno usage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210509225513.GF4038@breakpoint.cc>
Date:   Mon, 10 May 2021 00:55:13 +0200
From:   Florian Westphal <fw@...len.de>
To:     David Ahern <dsahern@...il.com>
Cc:     Florian Westphal <fw@...len.de>, netdev@...r.kernel.org
Subject: Re: [PATCH iproute2] mptcp: avoid uninitialised errno usage

David Ahern <dsahern@...il.com> wrote:
> >  	if (rtnl_talk(grth, &req.n, &answer) < 0) {
> >  		fprintf(stderr, "Error talking to the kernel\n");
> > +		if (errno == 0)
> > +			errno = EOPNOTSUPP;
> 
> you don't list the above string in the output in the commit log. Staring
> at rtnl_talk and recvmsg and its failure paths, it seems unlikely that
> path is causing the problem.

Its not in my particular case, but if it would caller would still get random errno.

The sketch I sent merely provides a relible errno whenever ret is less
than 0.  Right now it may or may not have been set.