[PATCH] x86: Fix memory leak of init_vdso_vars()

[Andy Lutomirski <luto@MIT.EDU>]

From: Zhitong Wang <wzt.wzt@gmail.com>

If init_vdso_vars ran out of memory (not very likely), then it would
leak a few pages as well.

Also rename init_vdso_vars to just init_vdso, since initializing
vvars is just about the only thing this function doesn't do.

Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
[Rebased and slightly simplified from the original.]
Signed-off-by: Andy Lutomirski <luto@mit.edu>
---
 arch/x86/vdso/vma.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index c39938d..cabaf0e 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -54,7 +54,7 @@ found:
 	apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
 }
 
-static int __init init_vdso_vars(void)
+static int __init init_vdso(void)
 {
 	int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE;
 	int i;
@@ -69,19 +69,24 @@ static int __init init_vdso_vars(void)
 		struct page *p;
 		p = alloc_page(GFP_KERNEL);
 		if (!p)
-			goto oom;
+			goto oom_free;
 		vdso_pages[i] = p;
 		copy_page(page_address(p), vdso_start + i*PAGE_SIZE);
 	}
 
 	return 0;
 
- oom:
+oom_free:
+	for(i--; i >= 0; i--)
+		__free_page(vdso_pages[i]);
+	__free_page(vdso_pages);
+
+oom:
 	printk("Cannot allocate vdso\n");
 	vdso_enabled = 0;
 	return -ENOMEM;
 }
-subsys_initcall(init_vdso_vars);
+subsys_initcall(init_vdso);
 
 struct linux_binprm;
 
-- 
1.7.6