From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Subject: Re: segfault on sscanf
Date: Thu, 14 Mar 2019 18:34:15 -0400 [thread overview]
Message-ID: <20190314223415.GH23599@brightrain.aerifal.cx> (raw)
In-Reply-To: <20190314194933.GK26605@port70.net>
On Thu, Mar 14, 2019 at 08:49:34PM +0100, Szabolcs Nagy wrote:
> * Markus Wichmann <nullplan@gmx.net> [2019-03-14 19:38:12 +0100]:
>
> > On Thu, Mar 14, 2019 at 07:19:19PM +0100, Szabolcs Nagy wrote:
> > > i think __shgetc should ensure f->rpos == f->shend on EOF
> >
> > What about shunget(), though? Currently, if shgetc() returns EOF, at the
>
> i meant f->rpos == f->shend == 0.
Changing f->rpos is not valid here; it would corrupt the state of the
FILE for furher use after the shgetc phase is done. This is especially
important if we reached the code due to shlim being hit, but I think
it also matters for __uflow failing; normally the FILE is left in read
mode, with rpos and rend pointers valid. If we were going to zero
rpos, we would also have to zero rend, taking it out of read mode, but
this does not seem desirable.
Rather, I think f->shend should be set to f->rpos, not 0. Does this
sound right?
Rich
next prev parent reply other threads:[~2019-03-14 22:34 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-14 9:46 Marian Buschsieweke
2019-03-14 12:44 ` A. Wilcox
2019-03-14 13:29 ` Szabolcs Nagy
2019-03-14 14:34 ` Pascal Cuoq
2019-03-14 16:28 ` Markus Wichmann
2019-03-14 16:53 ` Markus Wichmann
2019-03-14 18:19 ` Szabolcs Nagy
2019-03-14 18:38 ` Markus Wichmann
2019-03-14 19:49 ` Szabolcs Nagy
2019-03-14 20:15 ` Szabolcs Nagy
2019-03-14 22:34 ` Rich Felker [this message]
2019-03-14 22:43 ` Szabolcs Nagy
2019-03-14 22:52 ` Rich Felker
2019-03-15 1:54 ` Rich Felker
2019-03-14 22:40 ` Rich Felker
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