[PATCH] Remove a tiny memory leak in drivers/of

[Mathieu Malaterre]

On my PowerMac device-tree would generate a duplicate name:

[    0.023043] device-tree: Duplicate name in PowerPC,G4 at 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: Mathieu Malaterre <mathieu.malaterre at gmail.com>
---
 drivers/of/base.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index ebf84e3..3cb11df 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -174,11 +174,15 @@ int __of_attach_node_sysfs(struct device_node *np)
 		rc = kobject_add(&np->kobj, NULL, "%s",
 				 safe_name(&of_kset->kobj, "base"));
 	} else {
-		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+		const char *orig_name = kbasename(np->full_name);
+
+		name = safe_name(&np->parent->kobj, orig_name);
 		if (!name || !name[0])
 			return -EINVAL;
 
 		rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+		if (name != orig_name)
+			kfree(name);
 	}
 	if (rc)
 		return rc;
-- 
2.1.4