On Fri, Nov 25, 2016 at 07:08:53PM +0300, Nikita Yushchenko wrote:
> _dsa_register_switch() gets a dsa_switch_tree object either via
> dsa_get_dst() or via dsa_add_dst(). Former path does not increase kref
> in returned object (resulting into caller not owning a reference),
> while later path does create a new object (resulting into caller owning
> a reference).
>
> The rest of _dsa_register_switch() assumes that it owns a reference, and
> calls dsa_put_dst().
>
> This causes a memory breakage if first switch in the tree initialized
> successfully, but second failed to initialize. In particular, freed
> dsa_swith_tree object is left referenced by switch that was initialized,
> and later access to sysfs attributes of that switch cause OOPS.
>
> To fix, need to add kref_get() call to dsa_get_dst().
>
> Signed-off-by: Nikita Yushchenko <nikita.yo...@cogentembedded.com>
Hi Nikita
What tree is this against? It should be net. Please make the subject
[patch net] ... so it is clear what tree this is for.
And it should have a fixes-tag
Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation")
Reviewed-by: Andrew Lunn <and...@lunn.ch>
Andrew
> ---
> net/dsa/dsa2.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
> index f8a7d9aab437..5fff951a0a49 100644
> --- a/net/dsa/dsa2.c
> +++ b/net/dsa/dsa2.c
> @@ -28,8 +28,10 @@ static struct dsa_switch_tree *dsa_get_dst(u32 tree)
> struct dsa_switch_tree *dst;
>
> list_for_each_entry(dst, &dsa_switch_trees, list)
> - if (dst->tree == tree)
> + if (dst->tree == tree) {
> + kref_get(&dst->refcount);
> return dst;
> + }
> return NULL;
> }
>
> --
> 2.1.4
>
