Re: [net,v2,1/2] net: liquidio: Fix off-by-one error in setup_nic_devices() cleanup
From: Simon Horman
Date: Mon Jan 26 2026 - 10:56:29 EST
On Mon, Jan 26, 2026 at 03:50:39PM +0000, Simon Horman wrote:
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>
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> ---
> net: liquidio: Fix off-by-one error in setup_nic_devices() cleanup
>
> This patch changes the cleanup loop from while(i--) to do{}while(i--)
> to ensure that when a device fails to initialize, it gets cleaned up
> along with all previously initialized devices.
>
> > diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c
> > index 0732440eeacd..3ba2806f5d1e 100644
> > --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c
> > +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c
> > @@ -3765,11 +3765,11 @@ static int setup_nic_devices(struct octeon_device *octeon_dev)
> >
> > setup_nic_dev_free:
> >
> > - while (i--) {
> > + do {
> > dev_err(&octeon_dev->pci_dev->dev,
> > "NIC ifidx:%d Setup failed\n", i);
> > liquidio_destroy_nic_device(octeon_dev, i);
> > - }
> > + } while (i--);
>
> In lio_main.c, setup_nic_devices() can also reach setup_nic_dev_free from
> the devlink_alloc() failure path after the main for loop completes. At that
> point i equals ifcount (the loop counter has been incremented past the last
> valid device).
>
> With the do-while change, the first iteration will call
> liquidio_destroy_nic_device(octeon_dev, ifcount) for a device index that
> was never initialized. The function has a guard for NULL netdev so it will
> not crash, but it will print a spurious error message about a device that
> never existed.
>
> The fix works correctly for failures within the loop (which is the case
> described in the commit message), but is there a way to handle the
> post-loop devlink_alloc() failure case without printing the spurious
> error message?
Sorry for not realising this when I made this suggestion in
my review of v1.
Also, I would suggest splitting this patch in two: one patch
per driver.