From: Matthew Wilcox <matthew@wil.cx>
To: linux-kernel@vger.kernel.org
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, linux-serial@vger.kernel.org
Subject: Don't cross the (tty) streams
Date: Thu, 20 Sep 2007 15:02:22 -0600 [thread overview]
Message-ID: <20070920210221.GC10625@parisc-linux.org> (raw)
Connect two machines with a serial cable. On the victim:
willy@rowlf:~$ cat </dev/ttyS1
Now, let's find out which ttyS on the other machine is connected ...
willy@teeth:~$ echo foo >/dev/ttyS1
-bash: echo: write error: Input/output error
Oops, that's not a serial port. No output on rowlf, as expected.
OK, carrying on ...
willy@teeth:~$ echo bar >/dev/ttyS0
And yet on rowlf, we now see:
foo
bar
Looks like there's an error path that doesn't throw away data on -EIO.
This bug exists on at least these two kernels (because I tested it in
both directions:
Linux rowlf 2.6.19-rc6-g70d6673f #1 SMP Thu Nov 16 20:49:15 EST 2006 ia64 GNU/Linux
Linux teeth 2.6.23-rc3-g68dba7a9-dirty #209 SMP PREEMPT Thu Sep 20 15:57:42 EDT 2007 i686 GNU/Linux
Neither kernel has any modifications to its serial code.
--
Intel are signing my paycheques ... these opinions are still mine
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
next reply other threads:[~2007-09-20 21:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-20 21:02 Matthew Wilcox [this message]
2007-09-20 21:29 ` Don't cross the (tty) streams Andreas Schwab
2007-09-21 3:08 ` Matthew Wilcox
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