[PATCH v2 1/2] EDAC/device_sysfs: Fix calling kobject_put() with ->state_initialized unset
In edac_device_register_sysfs_main_kobj(), when dev_root is NULL, kobject_init_and_add() is not called.
if (err) { // err = -ENODEV edac_dbg(1, "Failed to register '.../edac/%s'\n", edac_dev->name); goto err_kobj_reg; // This calls kobj_put() }
This will cause a runtime warning in kobject_put() if the above happens. Warning: "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called."
Fix the error handling to avoid the above possible situation.
Cc: stable@vger.kernel.org Fixes: cb4a0bec0bb9 ("EDAC/sysfs: move to use bus_get_dev_root()") Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com --- This is based on static analysis and only compile tested. v1->v2: Resend as a patchset as they are two similar bugs. --- drivers/edac/edac_device_sysfs.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 010c26be5846..4cac14cbdb60 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -253,11 +253,13 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
/* register */ dev_root = bus_get_dev_root(edac_subsys); - if (dev_root) { - err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl, - &dev_root->kobj, "%s", edac_dev->name); - put_device(dev_root); - } + if (!dev_root) + goto module_put; + + err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl, + &dev_root->kobj, "%s", edac_dev->name); + put_device(dev_root); + if (err) { edac_dbg(1, "Failed to register '.../edac/%s'\n", edac_dev->name); @@ -276,8 +278,8 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* Error exit stack */ err_kobj_reg: kobject_put(&edac_dev->kobj); +module_put: module_put(edac_dev->owner); - err_out: return err; }
In edac_pci_main_kobj_setup() when dev_root is NULL, kobject_init_and_add() is not called.
if (err) { // err = -ENODEV; edac_dbg(1, "Failed to register '.../edac/pci'\n"); goto kobject_init_and_add_fail; // call to kobject_put() }
This will cause a runtime warning in kobject_put() if the above happens. Warning: "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called."
Fix the error handling to avoid the above possible situation.
Cc: stable@vger.kernel.org Fixes: cb4a0bec0bb9 ("EDAC/sysfs: move to use bus_get_dev_root()") Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com --- This is based on static analysis and only compile tested. v1->v2: Resend as a patchset as they fix two similar bugs with modified subject. --- drivers/edac/edac_pci_sysfs.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c index 287cc51dbc86..185ae9eda8a5 100644 --- a/drivers/edac/edac_pci_sysfs.c +++ b/drivers/edac/edac_pci_sysfs.c @@ -370,12 +370,14 @@ static int edac_pci_main_kobj_setup(void)
/* Instanstiate the pci object */ dev_root = bus_get_dev_root(edac_subsys); - if (dev_root) { - err = kobject_init_and_add(edac_pci_top_main_kobj, - &ktype_edac_pci_main_kobj, - &dev_root->kobj, "pci"); - put_device(dev_root); - } + if (!dev_root) + goto kzalloc_fail; + + err = kobject_init_and_add(edac_pci_top_main_kobj, + &ktype_edac_pci_main_kobj, + &dev_root->kobj, "pci"); + put_device(dev_root); + if (err) { edac_dbg(1, "Failed to register '.../edac/pci'\n"); goto kobject_init_and_add_fail;
Hi,
On 29/11/23 12:00 am, Harshit Mogalapalli wrote:
In edac_device_register_sysfs_main_kobj(), when dev_root is NULL, kobject_init_and_add() is not called.
if (err) { // err = -ENODEV edac_dbg(1, "Failed to register '.../edac/%s'\n", edac_dev->name); goto err_kobj_reg; // This calls kobj_put() }
This will cause a runtime warning in kobject_put() if the above happens. Warning: "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called."
Fix the error handling to avoid the above possible situation.
Cc: stable@vger.kernel.org Fixes: cb4a0bec0bb9 ("EDAC/sysfs: move to use bus_get_dev_root()") Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com
Ping on this two patch series:
Lore url: https://lore.kernel.org/all/20231128183037.3395755-1-harshit.m.mogalapalli@o...
Thanks, Harshit
This is based on static analysis and only compile tested. v1->v2: Resend as a patchset as they are two similar bugs.
drivers/edac/edac_device_sysfs.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 010c26be5846..4cac14cbdb60 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -253,11 +253,13 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* register */ dev_root = bus_get_dev_root(edac_subsys);
- if (dev_root) {
err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,&dev_root->kobj, "%s", edac_dev->name);put_device(dev_root);- }
- if (!dev_root)
goto module_put;- err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,
&dev_root->kobj, "%s", edac_dev->name);- put_device(dev_root);
- if (err) { edac_dbg(1, "Failed to register '.../edac/%s'\n", edac_dev->name);
@@ -276,8 +278,8 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* Error exit stack */ err_kobj_reg: kobject_put(&edac_dev->kobj); +module_put: module_put(edac_dev->owner);
- err_out: return err; }
On Tue, Nov 28, 2023 at 10:30:35AM -0800, Harshit Mogalapalli wrote:
In edac_device_register_sysfs_main_kobj(), when dev_root is NULL,
When is dev_root NULL?
A real use case or this is just from code staring?
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 010c26be5846..4cac14cbdb60 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -253,11 +253,13 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* register */ dev_root = bus_get_dev_root(edac_subsys);
- if (dev_root) {
err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,&dev_root->kobj, "%s", edac_dev->name);
What cb4a0bec0bb9 did looks wrong. That if (err) check should be inside the if (dev_root).
IOW, that function's error checking needs balancing. Something like this below.
And looking at the other one, it has the same issue...
--- diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 237a542e045a..3476ef13e681 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -228,8 +228,8 @@ static struct kobj_type ktype_device_ctrl = { */ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) { - struct device *dev_root; const struct bus_type *edac_subsys; + struct device *dev_root; int err = -ENODEV;
edac_dbg(1, "\n"); @@ -243,26 +243,26 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* Init the devices's kobject */ memset(&edac_dev->kobj, 0, sizeof(struct kobject));
- /* Record which module 'owns' this control structure - * and bump the ref count of the module + /* + * Record which module 'owns' this control structure and bump + * the ref count of the module */ edac_dev->owner = THIS_MODULE;
if (!try_module_get(edac_dev->owner)) goto err_out;
- /* register */ dev_root = bus_get_dev_root(edac_subsys); - if (dev_root) { - err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl, - &dev_root->kobj, "%s", edac_dev->name); - put_device(dev_root); - } + if (!dev_root) + goto err_module; + + err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl, + &dev_root->kobj, "%s", edac_dev->name); if (err) { - edac_dbg(1, "Failed to register '.../edac/%s'\n", - edac_dev->name); + edac_dbg(1, "Failed to register '.../edac/%s'\n", edac_dev->name); goto err_kobj_reg; } + kobject_uevent(&edac_dev->kobj, KOBJ_ADD);
/* At this point, to 'free' the control struct, @@ -273,9 +273,11 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
return 0;
- /* Error exit stack */ err_kobj_reg: kobject_put(&edac_dev->kobj); + put_device(dev_root); + +err_module: module_put(edac_dev->owner);
err_out:
On 25/01/24 6:39 pm, Borislav Petkov wrote:
On Tue, Nov 28, 2023 at 10:30:35AM -0800, Harshit Mogalapalli wrote:
In edac_device_register_sysfs_main_kobj(), when dev_root is NULL,
Thanks for checking this.
When is dev_root NULL?
A real use case or this is just from code staring?
This is based on static analysis, not real testing.
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 010c26be5846..4cac14cbdb60 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -253,11 +253,13 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* register */ dev_root = bus_get_dev_root(edac_subsys);
- if (dev_root) {
err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,&dev_root->kobj, "%s", edac_dev->name);What cb4a0bec0bb9 did looks wrong. That if (err) check should be inside the if (dev_root).
IOW, that function's error checking needs balancing. Something like this below.
And looking at the other one, it has the same issue...
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 237a542e045a..3476ef13e681 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -228,8 +228,8 @@ static struct kobj_type ktype_device_ctrl = { */ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) {
- struct device *dev_root; const struct bus_type *edac_subsys;
- struct device *dev_root; int err = -ENODEV;
edac_dbg(1, "\n"); @@ -243,26 +243,26 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) /* Init the devices's kobject */ memset(&edac_dev->kobj, 0, sizeof(struct kobject));
- /* Record which module 'owns' this control structure
* and bump the ref count of the module
- /*
* Record which module 'owns' this control structure and bump* the ref count of the moduleif (!try_module_get(edac_dev->owner)) goto err_out;
- /* register */ dev_root = bus_get_dev_root(edac_subsys);
- if (dev_root) {
err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,&dev_root->kobj, "%s", edac_dev->name);put_device(dev_root);- }
- if (!dev_root)
goto err_module;- err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,
&dev_root->kobj, "%s", edac_dev->name);
edac_dbg(1, "Failed to register '.../edac/%s'\n",edac_dev->name);
edac_dbg(1, "Failed to register '.../edac/%s'\n", edac_dev->name);- kobject_uevent(&edac_dev->kobj, KOBJ_ADD);
/* At this point, to 'free' the control struct, @@ -273,9 +273,11 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev) return 0;
- /* Error exit stack */ err_kobj_reg: kobject_put(&edac_dev->kobj);
- put_device(dev_root);
In this diff, put_device(dev_root) is not called on the success path. I checked couple of other callers of bus_get_dev_root() and they call put_device(dev_root) after using dev_root. I think we need to have put_device() on the success path as well.
+err_module: module_put(edac_dev->owner);
An alternate diff could be:
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c index 237a542e045a..0c8e66e40af8 100644 --- a/drivers/edac/edac_device_sysfs.c +++ b/drivers/edac/edac_device_sysfs.c @@ -275,7 +275,8 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
/* Error exit stack */ err_kobj_reg: - kobject_put(&edac_dev->kobj); + if(dev_root) + kobject_put(&edac_dev->kobj); module_put(edac_dev->owner);
err_out:
Thanks, Harshit
err_out:
linux-stable-mirror@lists.linaro.org
-
Borislav Petkov -
Harshit Mogalapalli