From 9cc3d0c6915aee5140f8335d41bbc3ff1b79aa4e Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 14 Apr 2020 11:42:48 +0100 Subject: [PATCH] arm64: vdso: don't free unallocated pages The aarch32_vdso_pages[] array never has entries allocated in the C_VVAR or C_VDSO slots, and as the array is zero initialized these contain NULL. However in __aarch32_alloc_vdso_pages() when aarch32_alloc_kuser_vdso_page() fails we attempt to free the page whose struct page is at NULL, which is obviously nonsensical. This patch removes the erroneous page freeing. Fixes: 7c1deeeb0130 ("arm64: compat: VDSO setup for compat layer") Cc: # 5.3.x- Cc: Vincenzo Frascino Acked-by: Will Deacon Signed-off-by: Mark Rutland Signed-off-by: Catalin Marinas --- arch/arm64/kernel/vdso.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 354b11e..033a48f 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -260,18 +260,7 @@ static int __aarch32_alloc_vdso_pages(void) if (ret) return ret; - ret = aarch32_alloc_kuser_vdso_page(); - if (ret) { - unsigned long c_vvar = - (unsigned long)page_to_virt(aarch32_vdso_pages[C_VVAR]); - unsigned long c_vdso = - (unsigned long)page_to_virt(aarch32_vdso_pages[C_VDSO]); - - free_page(c_vvar); - free_page(c_vdso); - } - - return ret; + return aarch32_alloc_kuser_vdso_page(); } #else static int __aarch32_alloc_vdso_pages(void) -- 2.7.4