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authorFrank Rowand <frank.rowand@am.sony.com>2016-06-16 10:51:46 -0700
committerRob Herring <robh@kernel.org>2016-06-24 15:16:10 -0500
commitd9fc880723321dbf16b2981e3f3e916b73942210 (patch)
tree0e483dcd218e52726f6669f74f64e036eb9f9420
parente1bcbee6f95301197e1039b4e4104cbdc4a332a6 (diff)
of: fix memory leak related to safe_name()
Fix a memory leak resulting from memory allocation in safe_name(). This patch fixes all call sites of safe_name(). Mathieu Malaterre reported the memory leak on boot: On my PowerMac device-tree would generate a duplicate name: [ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1" in this case a newly allocated name is generated by `safe_name`. However in this case it is never deallocated. The bug was found using kmemleak reported as: unreferenced object 0xdf532e60 (size 32): comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s) hex dump (first 32 bytes): 6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1...... ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................ backtrace: [<c02d3350>] kvasprintf+0x64/0xc8 [<c02d3400>] kasprintf+0x4c/0x5c [<c0453814>] safe_name.isra.1+0x80/0xc4 [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c [<c075f21c>] of_core_init+0x8c/0xf8 [<c0729594>] kernel_init_freeable+0xd4/0x208 [<c00047e8>] kernel_init+0x24/0x11c [<c00158ec>] ret_from_kernel_thread+0x5c/0x64 Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331 Signed-off-by: Frank Rowand <frank.rowand@am.sony.com> Reported-by: mathieu.malaterre@gmail.com Tested-by: Mathieu Malaterre <mathieu.malaterre@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
-rw-r--r--drivers/of/base.c30
-rw-r--r--drivers/of/dynamic.c2
-rw-r--r--drivers/of/of_private.h3
3 files changed, 25 insertions, 10 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ebf84e3b56d5..8bb3d1adf1b0 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -112,6 +112,7 @@ static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
}
+/* always return newly allocated name, caller must free after use */
static const char *safe_name(struct kobject *kobj, const char *orig_name)
{
const char *name = orig_name;
@@ -126,9 +127,12 @@ static const char *safe_name(struct kobject *kobj, const char *orig_name)
name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
}
- if (name != orig_name)
+ if (name == orig_name) {
+ name = kstrdup(orig_name, GFP_KERNEL);
+ } else {
pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
kobject_name(kobj), name);
+ }
return name;
}
@@ -159,6 +163,7 @@ int __of_add_property_sysfs(struct device_node *np, struct property *pp)
int __of_attach_node_sysfs(struct device_node *np)
{
const char *name;
+ struct kobject *parent;
struct property *pp;
int rc;
@@ -171,15 +176,16 @@ int __of_attach_node_sysfs(struct device_node *np)
np->kobj.kset = of_kset;
if (!np->parent) {
/* Nodes without parents are new top level trees */
- rc = kobject_add(&np->kobj, NULL, "%s",
- safe_name(&of_kset->kobj, "base"));
+ name = safe_name(&of_kset->kobj, "base");
+ parent = NULL;
} else {
name = safe_name(&np->parent->kobj, kbasename(np->full_name));
- if (!name || !name[0])
- return -EINVAL;
-
- rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+ parent = &np->parent->kobj;
}
+ if (!name)
+ return -ENOMEM;
+ rc = kobject_add(&np->kobj, parent, "%s", name);
+ kfree(name);
if (rc)
return rc;
@@ -1815,6 +1821,12 @@ int __of_remove_property(struct device_node *np, struct property *prop)
return 0;
}
+void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
+{
+ sysfs_remove_bin_file(&np->kobj, &prop->attr);
+ kfree(prop->attr.attr.name);
+}
+
void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
{
if (!IS_ENABLED(CONFIG_SYSFS))
@@ -1822,7 +1834,7 @@ void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
/* at early boot, bail here and defer setup to of_init() */
if (of_kset && of_node_is_attached(np))
- sysfs_remove_bin_file(&np->kobj, &prop->attr);
+ __of_sysfs_remove_bin_file(np, prop);
}
/**
@@ -1895,7 +1907,7 @@ void __of_update_property_sysfs(struct device_node *np, struct property *newprop
return;
if (oldprop)
- sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+ __of_sysfs_remove_bin_file(np, oldprop);
__of_add_property_sysfs(np, newprop);
}
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 3033fa3250dc..a2015599ed7e 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -55,7 +55,7 @@ void __of_detach_node_sysfs(struct device_node *np)
/* only remove properties if on sysfs */
if (of_node_is_attached(np)) {
for_each_property_of_node(np, pp)
- sysfs_remove_bin_file(&np->kobj, &pp->attr);
+ __of_sysfs_remove_bin_file(np, pp);
kobject_del(&np->kobj);
}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 829469faeb23..18bbb4517e25 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -83,6 +83,9 @@ extern int __of_attach_node_sysfs(struct device_node *np);
extern void __of_detach_node(struct device_node *np);
extern void __of_detach_node_sysfs(struct device_node *np);
+extern void __of_sysfs_remove_bin_file(struct device_node *np,
+ struct property *prop);
+
/* iterators for transactions, used for overlays */
/* forward iterator */
#define for_each_transaction_entry(_oft, _te) \