The call to of_get_cpu_node/of_find_compatible_node/of_parse_phandle...
returns a node pointer with refcount incremented thus it must be
explicitly decremented after the last usage.
We developed a coccinelle SmPL to detect drivers/firmware code and
found some issues.
This patch series fixes those issues.
Wen Yang (3):
firmware: arm_sdei: fix leaked of_node references
firmware: psci: fix leaked of_node references
firmware: stratix10-svc: fix leaked of_node references
drivers/firmware/arm_sdei.c | 1 +
drivers/firmware/psci.c | 4 +++-
drivers/firmware/stratix10-svc.c | 14 ++++++++++----
3 files changed, 14 insertions(+), 5 deletions(-)
--
2.9.5
The call to of_find_matching_node_and_match returns a node pointer
with refcount incremented thus it must be explicitly decremented
after the last usage.
672 int __init psci_dt_init(void)
673 {
674 struct device_node *np;
...
678 np = of_find_matching_node_and_match(...);
679
680 if (!np || !of_device_is_available(np))
682 return -ENODEV; ---> leaked here
...
686 return init_fn(np); ---> released here
687 }
Detected by using coccinelle.
Signed-off-by: Wen Yang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/firmware/psci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index c80ec1d..e4143f8 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -677,8 +677,10 @@ int __init psci_dt_init(void)
np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
- if (!np || !of_device_is_available(np))
+ if (!np || !of_device_is_available(np)) {
+ of_node_put(np);
return -ENODEV;
+ }
init_fn = (psci_initcall_t)matched_np->data;
return init_fn(np);
--
2.9.5
In stratix10_svc_init function, fw_np is obtained by calling
of_find_node_by_name(), np is obtained by calling
of_find_matching_node(), and the reference counts of those
two device_nodes, fw_np and np, are increased.
But when the function exits, only of_node_put is called on np,
and fw_np's reference count is leaked.
Detected by coccinelle with the following warnings:
./drivers/firmware/stratix10-svc.c:1020:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1014, but without a corresponding object release within this function.
./drivers/firmware/stratix10-svc.c:1025:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1014, but without a corresponding object release within this function.
./drivers/firmware/stratix10-svc.c:1027:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1014, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Alan Tull <[email protected]>
Cc: Richard Gong <[email protected]>
Cc: Nicolas Saenz Julienne <[email protected]>
Cc: [email protected]
---
drivers/firmware/stratix10-svc.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
index 6e65148..482a6bd 100644
--- a/drivers/firmware/stratix10-svc.c
+++ b/drivers/firmware/stratix10-svc.c
@@ -1016,15 +1016,21 @@ static int __init stratix10_svc_init(void)
return -ENODEV;
np = of_find_matching_node(fw_np, stratix10_svc_drv_match);
- if (!np)
- return -ENODEV;
+ if (!np) {
+ ret = -ENODEV;
+ goto out_put_fw_np;
+ }
of_node_put(np);
ret = of_platform_populate(fw_np, stratix10_svc_drv_match, NULL, NULL);
if (ret)
- return ret;
+ goto out_put_fw_np;
- return platform_driver_register(&stratix10_svc_driver);
+ ret = platform_driver_register(&stratix10_svc_driver);
+
+out_put_fw_np:
+ of_node_put(fw_np);
+ return ret;
}
static void __exit stratix10_svc_exit(void)
--
2.9.5
In sdei_present_dt function, fw_np is obtained by calling
of_find_node_by_name(), np is obtained by calling
of_find_matching_node(), and the reference counts of those
two device_nodes, fw_np and np, are increased.
But when the function exits, only of_node_put is called on np,
and fw_np's reference count is leaked.
Detected by coccinelle with the following warnings:
./drivers/firmware/arm_sdei.c:1088:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1082, but without a corresponding object release within this function.
./drivers/firmware/arm_sdei.c:1091:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1082, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <[email protected]>
Cc: James Morse <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/firmware/arm_sdei.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index e6376f9..2faa329 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -1084,6 +1084,7 @@ static bool __init sdei_present_dt(void)
return false;
np = of_find_matching_node(fw_np, sdei_of_match);
+ of_node_put(fw_np);
if (!np)
return false;
of_node_put(np);
--
2.9.5
On Wed, 2019-04-17 at 10:44 +0800, Wen Yang wrote:
> In stratix10_svc_init function, fw_np is obtained by calling
> of_find_node_by_name(), np is obtained by calling
> of_find_matching_node(), and the reference counts of those
> two device_nodes, fw_np and np, are increased.
> But when the function exits, only of_node_put is called on np,
> and fw_np's reference count is leaked.
>
> Detected by coccinelle with the following warnings:
> ./drivers/firmware/stratix10-svc.c:1020:2-8: ERROR: missing of_node_put;
> acquired a node pointer with refcount incremented on line 1014, but without a
> corresponding object release within this function.
> ./drivers/firmware/stratix10-svc.c:1025:2-8: ERROR: missing of_node_put;
> acquired a node pointer with refcount incremented on line 1014, but without a
> corresponding object release within this function.
> ./drivers/firmware/stratix10-svc.c:1027:1-7: ERROR: missing of_node_put;
> acquired a node pointer with refcount incremented on line 1014, but without a
> corresponding object release within this function.
>
> Signed-off-by: Wen Yang <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: Alan Tull <[email protected]>
> Cc: Richard Gong <[email protected]>
> Cc: Nicolas Saenz Julienne <[email protected]>
> Cc: [email protected]
> ---
> drivers/firmware/stratix10-svc.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-
> svc.c
> index 6e65148..482a6bd 100644
> --- a/drivers/firmware/stratix10-svc.c
> +++ b/drivers/firmware/stratix10-svc.c
> @@ -1016,15 +1016,21 @@ static int __init stratix10_svc_init(void)
> return -ENODEV;
>
> np = of_find_matching_node(fw_np, stratix10_svc_drv_match);
Sorry but this patch isn't right, of_find_matching_node() will free the
reference to fw_np internally.
> - if (!np)
> - return -ENODEV;
> + if (!np) {
> + ret = -ENODEV;
> + goto out_put_fw_np;
> + }
>
> of_node_put(np);
> ret = of_platform_populate(fw_np, stratix10_svc_drv_match, NULL, NULL);
> if (ret)
> - return ret;
> + goto out_put_fw_np;
Consequently and assuming I'm not missing something, I think fw_np shouldn't be
used here as is.
Regards,
Nicolas