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Commit 7a67a00e authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Greg Kroah-Hartman
Browse files

s390/kasan: fix large PMD pages address alignment check 



[ Upstream commit ddd63c85ef67ea9ea7282ad35eafb6568047126e ]

It is currently possible to initialize a large PMD page when
the address is not aligned on page boundary.

Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 98296eb3

arch/s390/mm/kasan_init.c

+20 −21
Original line number Diff line number Diff line
@@ -101,6 +101,9 @@ static void __init kasan_early_vmemmap_populate(unsigned long address, 
	pgt_prot = pgprot_val(PAGE_KERNEL_EXEC);

	sgt_prot = pgprot_val(SEGMENT_KERNEL_EXEC);



	/*

	 * The first 1MB of 1:1 mapping is mapped with 4KB pages

	 */

	while (address < end) {

		pg_dir = pgd_offset_k(address);

		if (pgd_none(*pg_dir)) {
@@ -146,17 +149,13 @@ static void __init kasan_early_vmemmap_populate(unsigned long address, 


		pm_dir = pmd_offset(pu_dir, address);

		if (pmd_none(*pm_dir)) {

			if (mode == POPULATE_ZERO_SHADOW &&

			    IS_ALIGNED(address, PMD_SIZE) &&

			if (IS_ALIGNED(address, PMD_SIZE) &&

			    end - address >= PMD_SIZE) {

				pmd_populate(&init_mm, pm_dir,

						kasan_early_shadow_pte);

				if (mode == POPULATE_ZERO_SHADOW) {

					pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);

					address = (address + PMD_SIZE) & PMD_MASK;

					continue;

			}

			/* the first megabyte of 1:1 is mapped with 4k pages */

			if (has_edat && address && end - address >= PMD_SIZE &&

			    mode != POPULATE_ZERO_SHADOW) {

				} else if (has_edat && address) {

					void *page;



					if (mode == POPULATE_ONE2ONE) {
@@ -169,7 +168,7 @@ static void __init kasan_early_vmemmap_populate(unsigned long address, 
					address = (address + PMD_SIZE) & PMD_MASK;

					continue;

				}



			}

			pt_dir = kasan_early_pte_alloc();

			pmd_populate(&init_mm, pm_dir, pt_dir);

		} else if (pmd_large(*pm_dir)) {