From f46c8a75263f97bda13c739ba1c90aced0d3b071 Mon Sep 17 00:00:00 2001
From: Kunwu Chan <chentao@kylinos.cn>
Date: Mon, 4 Dec 2023 10:32:23 +0800
Subject: [PATCH] powerpc/mm: Fix null-pointer dereference in pgtable_cache_add
References: CVE-2023-52607 bsc#1221061
Patch-mainline: v6.8-rc1
Git-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: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231204023223.2447523-1-chentao@kylinos.cn
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/mm/init-common.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -126,7 +126,7 @@ 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
@@ -139,7 +139,8 @@ void pgtable_cache_add(unsigned int shift)
align = max_t(unsigned long, align, minalign);
name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
- new = kmem_cache_create(name, table_size, align, 0, ctor);
+ if (name)
+ new = kmem_cache_create(name, table_size, align, 0, ctor);
if (!new)
panic("Could not allocate pgtable cache for order %d", shift);
--
2.44.0