From: Kunwu Chan <chentao@kylinos.cn>
To: mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu
Cc: kunwu.chan@hotmail.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, Kunwu Chan <chentao@kylinos.cn>
Subject: [PATCH v3] powerpc/mm: Fix null-pointer dereference in pgtable_cache_add
Date: Mon, 4 Dec 2023 10:32:23 +0800 [thread overview]
Message-ID: <20231204023223.2447523-1-chentao@kylinos.cn> (raw)
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>
---
v2: Use "panic" instead of "return"
v3: Merge two "panic" to one
---
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
index 119ef491f797..d3a7726ecf51 100644
--- 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(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);
--
2.34.1
WARNING: multiple messages have this Message-ID (diff)
From: Kunwu Chan <chentao@kylinos.cn>
To: mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Kunwu Chan <chentao@kylinos.cn>,
kunwu.chan@hotmail.com
Subject: [PATCH v3] powerpc/mm: Fix null-pointer dereference in pgtable_cache_add
Date: Mon, 4 Dec 2023 10:32:23 +0800 [thread overview]
Message-ID: <20231204023223.2447523-1-chentao@kylinos.cn> (raw)
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>
---
v2: Use "panic" instead of "return"
v3: Merge two "panic" to one
---
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
index 119ef491f797..d3a7726ecf51 100644
--- 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(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);
--
2.34.1
next reply other threads:[~2023-12-04 2:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-04 2:32 Kunwu Chan [this message]
2023-12-04 2:32 ` [PATCH v3] powerpc/mm: Fix null-pointer dereference in pgtable_cache_add Kunwu Chan
2023-12-21 10:38 ` Michael Ellerman
2023-12-21 10:38 ` Michael Ellerman
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