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Commit f6781add authored by Kunwu Chan's avatar Kunwu Chan Committed by Greg Kroah-Hartman
Browse files

powerpc/mm: Fix null-pointer dereference in pgtable_cache_add 



[ Upstream commit f46c8a75263f97bda13c739ba1c90aced0d3b071 ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Suggested-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarKunwu Chan <chentao@kylinos.cn>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231204023223.2447523-1-chentao@kylinos.cn


Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 3cdbfac1

arch/powerpc/mm/init-common.c

+3 −2
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ void pgtable_cache_add(unsigned int shift) 
	 * as to leave enough 0 bits in the address to contain it. */

	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,

				     HUGEPD_SHIFT_MASK + 1);

	struct kmem_cache *new;

	struct kmem_cache *new = NULL;



	/* It would be nice if this was a BUILD_BUG_ON(), but at the

	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
@@ -117,6 +117,7 @@ void pgtable_cache_add(unsigned int shift) 


	align = max_t(unsigned long, align, minalign);

	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);

	if (name)

		new = kmem_cache_create(name, table_size, align, 0, ctor(shift));

	if (!new)

		panic("Could not allocate pgtable cache for order %d", shift);