From: Rich Felker <dalias@aerifal.cx>
To: musl@lists.openwall.com
Subject: Re: proposed popen replacement using posix_spawn
Date: Sat, 23 Mar 2013 21:45:26 -0400 [thread overview]
Message-ID: <20130324014526.GY20323@brightrain.aerifal.cx> (raw)
In-Reply-To: <20130324014057.GX20323@brightrain.aerifal.cx>
On Sat, Mar 23, 2013 at 09:40:57PM -0400, Rich Felker wrote:
> /* Remove close-on-exec flag if dup2 will be a no-op in the child */
> if (p[1-op] == 1-op) fcntl(1-op, F_SETFD, 0);
This part is wrong; it creates a file descriptor leak race condition
in the parent. The only solution I can see is that the parent must
ensure p[1-op]!=1-op before calling posix_spawn. The easiest way to do
that is to move p[1-op] to a new fd number using F_DUPFD_CLOEXEC when
this happens, and fail the entire operation if this fails. I'll update
the code accordingly.
Rich
prev parent reply other threads:[~2013-03-24 1:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-24 1:40 Rich Felker
2013-03-24 1:40 ` Rich Felker
2013-03-24 1:45 ` Rich Felker [this message]
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