Commit 963938f5 authored Oct 14, 2019 by Pavel Tatashin Committed by Greg Kroah-Hartman Jan 27, 2020

arm64: hibernate: check pgd table allocation



[ Upstream commit 8c551f919a73c1dfa690a70a691be1da394145e8 ]

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: 82869ac5 ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent b79d3800

arch/arm64/kernel/hibernate.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -202,6 +202,7 @@ static int create_safe_exec_page(void *src_start, size_t length,
		gfp_t mask)
		{
		int rc = 0;
		pgd_t *trans_pgd;
		pgd_t *pgdp;
		pud_t *pudp;
		pmd_t *pmdp;
		@@ -216,7 +217,13 @@ static int create_safe_exec_page(void *src_start, size_t length,
		memcpy((void *)dst, src_start, length);
		__flush_icache_range(dst, dst + length);

		pgdp = pgd_offset_raw(allocator(mask), dst_addr);
		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);
		if (!pudp) {