[PATCH] arm64: vdso: fix AArch32 compat init allocation leaks

[Osama Abdelkader]

aarch32_alloc_vdso_pages() allocates the AA32 vdso pagelist, the compat
sigpage, then the kuser vectors page. If aarch32_alloc_sigpage() or
aarch32_alloc_kuser_vdso_page() fails, earlier allocations were not freed.

Unwind in reverse order: drop the sigpage when kuser setup fails, and
kfree the vdso pagelist when either later step fails (only when
CONFIG_COMPAT_VDSO allocated it).

Signed-off-by: Osama Abdelkader <osama.abdelkader@xxxxxxxxx>
---
 arch/arm64/kernel/vdso.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 592dd8668de4..9903bfdfd45e 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -236,9 +236,27 @@ static int __init aarch32_alloc_vdso_pages(void)
 
 	ret = aarch32_alloc_sigpage();
 	if (ret)
-		return ret;
+		goto free_vdso;
+
+	ret = aarch32_alloc_kuser_vdso_page();
+	if (ret)
+		goto free_sig;
+
+	return 0;
 
-	return aarch32_alloc_kuser_vdso_page();
+free_sig:
+	if (aarch32_sig_page) {
+		__free_page(aarch32_sig_page);
+		aarch32_sig_page = NULL;
+	}
+free_vdso:
+#ifdef CONFIG_COMPAT_VDSO
+	if (vdso_info[VDSO_ABI_AA32].cm && vdso_info[VDSO_ABI_AA32].cm->pages) {
+		kfree(vdso_info[VDSO_ABI_AA32].cm->pages);
+		vdso_info[VDSO_ABI_AA32].cm->pages = NULL;
+	}
+#endif
+	return ret;
 }
 arch_initcall(aarch32_alloc_vdso_pages);
 
-- 
2.43.0