[asterisk-dev] [Code Review] Don't read past then end of our int when calling write() in __ast_queue_frame

[wdoekes]

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Ship it!


Ok. I'm convinced :)

- wdoekes


On Nov. 11, 2011, 10:25 p.m., Terry Wilson wrote:
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> (Updated Nov. 11, 2011, 10:25 p.m.)
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> 
> Review request for Asterisk Developers.
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> Summary
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> int blah = 1;
> ...
> write(chan->alertpipe[1], &blah, new_frames * sizeof(blah)) != (new_frames * sizeof(blah)))
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> is only valid when new_frames == 1. Otherwise we start reading into adjacent variables declared on the stack. The read end discards what is read, so the values don't matter but it's not a good idea to read past where we want event though new_frames is almost always 1 and should never be large. This patch is basically taken out of kpfleming's eventfd branch, as he mentioned that he remembered fixing it there when I talked to him about this issue.
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> Another thing that could be done is to change blah to a char[] here and where we read from the alertpipe. There is no reason to write four bytes when we could just write one, but I can address that in a later patch.
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> Diffs
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>   /branches/1.8/main/channel.c 344438 
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> Diff: https://reviewboard.asterisk.org/r/1583/diff
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> Testing
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> It compiles. Calls still seem to work.
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> Thanks,
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> Terry
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>

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