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From: Harald van Dijk <harald@gigawatt.nl>
To: Denys Vlasenko <vda.linux@googlemail.com>,
	Martijn Dekker <martijn@inlv.org>,
	Herbert Xu <herbert@gondor.apana.org.au>
Cc: dash@vger.kernel.org, busybox <busybox@busybox.net>
Subject: Re: [BUG] Interactive (d)ash exits on assigning to readonly from 'command eval'
Date: Sat, 29 Oct 2016 20:22:00 +0200	[thread overview]
Message-ID: <501f83a0-9a46-f4af-dc56-ba8db958bad1@gigawatt.nl> (raw)
In-Reply-To: <CAK1hOcO25fYP71DRxk=Dga5UZ6=FfmdDHTj6AWNNGSu_J0B+Dw@mail.gmail.com>

On 28/10/16 15:55, Denys Vlasenko wrote:
> This will probably be mangled by gmail, but here is the proposed fix:

This looks about the right approach, but it causes problems in 
subshells, a double free:

$ ./busybox ash -c 'readonly x; echo $(command eval x=2)'
ash: eval: line 1: x: is read only
*** Error in `./busybox': free(): invalid pointer: 0x000055a784c1c300 ***

That's with busybox checked out from git (commit 
9db74e49e5b462089c6eec0182d819c0d4708e57), where your patch is applied, 
completely unpatched and completely default config.

I omitted the backtrace output, but it's popfile() getting called, after 
popallfiles() has already been called.

Harald van Dijk

  reply	other threads:[~2016-10-29 18:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-27 21:40 Martijn Dekker
2016-10-28 13:55 ` Denys Vlasenko
2016-10-29 18:22   ` Harald van Dijk [this message]
2016-10-30 17:32     ` Denys Vlasenko

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