Re: [PATCH 1/3] w1: fix netlink refcnt leak on error path

From: David Fries
Date: Wed Apr 09 2014 - 00:31:43 EST


This patch is a bug fix, and I see from the mailing list I'm not the
only one to run into this bug, so it would be nice for this patch to
make it into this merge window. I didn't tag this one for stable
because it doesn't apply cleanly due to previous changes that did make
it into the merge window. Let me know if I should rewrite it for
stable and which kernel version.

The other two patches are more feature based changes.

On Tue, Apr 08, 2014 at 10:37:07PM -0500, David Fries wrote:
> If the message type is W1_MASTER_CMD or W1_SLAVE_CMD, then a reference
> is taken when searching for the slave or master device. If there
> isn't any following data m->len (mlen is a copy) is 0 and packing up
> the message for later execution is skipped leaving nothing to
> decrement the reference counts.
>
> Way back when, m->len was checked before the search that increments the
> reference count, but W1_LIST_MASTERS has no additional data, the check
> was moved in 9be62e0b2fadaf5ff causing this bug.
>
> This change reorders to put the check before the reference count is
> incremented avoiding the problem.
>
> Signed-off-by: David Fries <David@xxxxxxxxx>
> Acked-by: Evgeniy Polyakov <zbr@xxxxxxxxxxx>

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