Re: [PATCH v2] powerpc/85xx: Fix reference leak in xes_mpc85xx_setup_arch
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2022-07-29 06:53:51
Also in:
lkml
Miaoqian Lin [off-list ref] writes:
quoted hunk ↗ jump to hunk
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 <redacted> --- changes in v2: - update Fixes tag. v1 Link: https://lore.kernel.org/all/20220603120907.19999-1-linmq006@gmail.com (local) --- 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