Messages in this thread | | | Date | Wed, 27 Feb 2019 07:08:20 +0100 (CET) | From | Julia Lawall <> | Subject | RE: question about drivers/phy/renesas/phy-rcar-gen2.c |
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On Wed, 27 Feb 2019, Yoshihiro Shimoda wrote:
> Hello, > > > From: Julia Lawall, Sent: Tuesday, February 26, 2019 6:01 PM > > > > On Tue, 26 Feb 2019, Yoshihiro Shimoda wrote: > > > > > Hello, > > > (Sergei made this code, so I added his email as CC) > > > > > > I'm sorry for the delayed response. > > > > > > > From: Julia Lawall, Sent: Sunday, February 3, 2019 4:03 PM > > > > > > > > Hello, > > > > > > > > I was wondering whether phy-rcar-gen2.c would use dynamically allocated > > > > device nodes? > > > > > > I'm sorry, but what is "dynamically allocated device nodes"? > > > > Device nodes for which there will be a meor leak if one doesn't put > > of_node_put. > > Thank you. I understood it. > > > julia > > > > > > > > Best regards, > > > Yoshihiro Shimoda > > > > > > > If so, it looks like the following code could cause a > > > > use-after-free, due to not incrementing th reference count: > > > > > > > > for_each_child_of_node(dev->of_node, np) { > > > > struct rcar_gen2_channel *channel = drv->channels + i; > > > > u32 channel_num; > > > > int error, n; > > > > > > > > channel->of_node = np; > > IIUC, since the channel->of_node will be used for comparing the pointer > in rcar_gen2_phy_xlate(), it is not use-after-free. > However, the for_each_child_of_node() in rcar_gen2_phy_probe() will return > without of_put_node() at error paths. So, I'll submit a bugfix patch later. > > Thank you very much for your report!
Thanks for taking care of it.
julia
> > Best regards, > Yoshihiro Shimoda > > > > > ... > > > > } > > > > > > > > On the other hand, if the reference cound it incrememnted, preventing > > > > memory leaks in the case where the probe function fails would entail some > > > > complex rewriting of the code, so I thought it would be better to ask > > > > first. > > > > > > > > thanks, > > > > julia > > > >
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