linux-kernel - Re: pty tcdrain() bug in 2.6.27 to 2.6.30/current

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] [day] [month] [year] [list]

Date:	Wed, 10 Jun 2009 10:51:18 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	"Luke-Jr" <luke@...hjr.org>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: pty tcdrain() bug in 2.6.27 to 2.6.30/current

> manner. The following test case reproduces the bug, and hangs only on affected 
> kernels. Examination of 2.6.26 and 2.6.27 suggests the ioctl used by tcdrain 
> underwent a rewrite for 2.6.27, and thus fixing this bug is beyond my 
> capabilities at this time.

I don't see a bug at this point

> 	slavefd = open(ptsname(masterfd), O_NOCTTY | O_RDWR);
> 	assert(slavefd != -1);
> 	
> 	assert(sizeof(test) == write(slavefd, test, sizeof(test)));

Queue data to the other end...

> 	assert(!tcdrain(slavefd));

Wait for it to be read, but with nothing reading it.

So it waits as it should.


What is the bug here ?

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/