Re: [PATCH] crypto: caam: fix netdev memory leak in dpaa2_caam_probe

[Chang, Jianpeng (CN)]

On 1/16/2026 5:46 PM, Breno Leitao wrote:
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> On Fri, Jan 16, 2026 at 09:44:55AM +0800, Jianpeng Chang wrote:
> > When commit 0e1a4d427f58 ("crypto: caam: Unembed net_dev structure in
> > dpaa2") converted embedded net_device to dynamically allocated pointers,
> > it added cleanup in dpaa2_dpseci_disable() but missed adding cleanup in
> > dpaa2_dpseci_free() for error paths.
> >
> > This causes memory leaks when dpaa2_dpseci_dpio_setup() fails during probe
> > due to DPIO devices not being ready yet. The kernel's deferred probe
> > mechanism handles the retry successfully, but the netdevs allocated during
> > the failed probe attempt are never freed, resulting in kmemleak reports
> > showing multiple leaked netdev-related allocations all traced back to
> > dpaa2_caam_probe().
> >
> > Fix this by preserving the CPU mask of allocated netdevs during setup and
> > using it for cleanup in dpaa2_dpseci_free(). This approach ensures that
> > only the CPUs that actually had netdevs allocated will be cleaned up,
> > avoiding potential issues with CPU hotplug scenarios.
> >
> > Fixes: 0e1a4d427f58 ("crypto: caam: Unembed net_dev structure in dpaa2")
> > Signed-off-by: Jianpeng Chang <jianpeng.chang.cn@xxxxxxxxxxxxx>
> > ---
> >   drivers/crypto/caam/caamalg_qi2.c | 31 ++++++++++++++++---------------
> >   drivers/crypto/caam/caamalg_qi2.h |  2 ++
> >   2 files changed, 18 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
> > index 107ccb2ade42..a66c62174a0f 100644
> > --- a/drivers/crypto/caam/caamalg_qi2.c
> > +++ b/drivers/crypto/caam/caamalg_qi2.c
> > @@ -4810,6 +4810,17 @@ static void dpaa2_dpseci_congestion_free(struct dpaa2_caam_priv *priv)
> >        kfree(priv->cscn_mem);
> >   }
> >
> > +static void free_dpaa2_pcpu_netdev(struct dpaa2_caam_priv *priv, const cpumask_t *cpus)
> > +{
> > +     struct dpaa2_caam_priv_per_cpu *ppriv;
> > +     int i;
> > +
> > +     for_each_cpu(i, cpus) {
> > +             ppriv = per_cpu_ptr(priv->ppriv, i);
> > +             free_netdev(ppriv->net_dev);
> > +     }
> > +}
>
> Why is the function being moved here? Please keep code movement separate
> from functional changes, or at minimum explain why the move is necessary
> in the commit message.
Thank you for the feedback.

I moved the function because I thought reusing existing code would be 
cleaner in dpaa2_dpseci_free. I will add the explain in commit message.

For future reference, what's the preferred approach when needing to 
reuse a simple function (4-line loop) defined later in the file - 
forward declaration, move it with a separate change or just implement 
directly?
Thanks for the guidance.

Regards,
Jianpeng