[PATCH v4 03/17] arm64: hibernate: check pgd table allocation

From: Pavel Tatashin
Date: Mon Sep 09 2019 - 14:12:38 EST


There is a bug in create_safe_exec_page(), when page table is allocated
it is not checked that table is allocated successfully:

But it is dereferenced in: pgd_none(READ_ONCE(*pgdp)). Check that
allocation was successful.

Fixes: 82869ac57b5d ("arm64: kernel: Add support for hibernate/suspend-to-disk")

Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
arch/arm64/kernel/hibernate.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 025221564252..227cc26720f7 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -217,6 +217,11 @@ static int create_safe_exec_page(void *src_start, size_t length,
__flush_icache_range(dst, dst + length);

trans_pgd = allocator(mask);
+ if (!trans_pgd) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
pgdp = pgd_offset_raw(trans_pgd, dst_addr);
if (pgd_none(READ_ONCE(*pgdp))) {
pudp = allocator(mask);
--
2.23.0