From: Pavel Tatashin pasha.tatashin@soleen.com
[ 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: 82869ac57b5d ("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 --- arch/arm64/kernel/hibernate.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 9859e1178e6b..dbeeeffdb9c9 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -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) {