Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v2] powerpc/85xx: Fix reference leak in xes_mpc85xx_setup_arch | Date | Fri, 29 Jul 2022 16:53:06 +1000 |
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Miaoqian Lin <linmq006@gmail.com> writes: > of_find_node_by_path() returns remote device nodepointer with > refcount incremented, we should use of_node_put() on it when done. > Add missing of_node_put() to avoid refcount leak. > > Fixes: 3038acf9091f ("powerpc/85xx: Add platform support for X-ES MPC85xx boards") > Signed-off-by: Miaoqian Lin <linmq006@gmail.com> > --- > changes in v2: > - update Fixes tag. > v1 Link: https://lore.kernel.org/all/20220603120907.19999-1-linmq006@gmail.com > --- > arch/powerpc/platforms/85xx/xes_mpc85xx.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/powerpc/platforms/85xx/xes_mpc85xx.c b/arch/powerpc/platforms/85xx/xes_mpc85xx.c > index 5836e4ecb7a0..93f67b430714 100644 > --- a/arch/powerpc/platforms/85xx/xes_mpc85xx.c > +++ b/arch/powerpc/platforms/85xx/xes_mpc85xx.c > @@ -130,6 +130,8 @@ static void __init xes_mpc85xx_setup_arch(void) > mpc85xx_smp_init(); > > fsl_pci_assign_primary(); > + > + of_node_put(root); > }
For context, here is the full function:
static void __init xes_mpc85xx_setup_arch(void) { struct device_node *root; const char *model = "Unknown";
root = of_find_node_by_path("/"); if (root == NULL) return;
model = of_get_property(root, "model", NULL);
printk(KERN_INFO "X-ES MPC85xx-based single-board computer: %s\n", model + strlen("xes,"));
xes_mpc85xx_fixups();
mpc85xx_smp_init();
fsl_pci_assign_primary(); }
So yes it's missing an of_node_put(root).
But rather than add the of_node_put(), it would be simpler to just use of_root directly, then it doesn't need an of_node_put() at all.
But then look closer. To begin with model is assigned "Unknown", but then unconditionally overwritten by the of_get_property() call. So that's a waste of space.
And then if there's no model property of_get_property() will return NULL, and then the model + strlen("xes,") would oops.
And all of that just to print the model at boot, which is not really necessary, anyone who cares can look it up in /proc/device-tree after the system has booted.
So please just remove the lookup and printing of model entirely.
cheers
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