From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: False positive coverity bug id: 1351218
Date: Thu, 18 Feb 2016 15:49:58 +0000
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To: Harmandeep Kaur <write.harmandeep@gmail.com>, xen-devel@lists.xenproject.org, Dario Faggioli <dario.faggioli@citrix.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, ian.jackson@eu.citrix.com, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Ian Campbell <ian.campbell@citrix.com>, Wei Liu <wei.liu2@citrix.com>
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On 18/02/16 15:36, Harmandeep Kaur wrote:
> This is about a Coverity bug (included in the end), which I think is
> a false positive. I don't think pagesize can be zero in any case.
> pagesize = 1 << (((flags >> TMEM_POOL_PAGESIZE_SHIFT) &
>                             TMEM_POOL_PAGESIZE_MASK) + 12);
>
> Which means "pagesize > bufsize" will always be true and buf can
> not be null in any case if it reaches line 464 (or call may terminate
> if realloc(..) returns NULL).

I would agree that given the "1 <<", pagesize will always be larger than
0, and therefore call realloc().

However, every iteration of the
"while ( read_exact(io_fd, &pool_id, sizeof(pool_id)) == 0 && pool_id != -1 )"
loop leaks buf, as do most of the error paths.

This function is currently orphaned code (since Xen 4.6), and in need of
some re-development before it can be used again.  I wouldn't worry too
much about fixing it up.

~Andrew