From: Hui Zhu <hui.zhu@linux.dev>
To: Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>,
Nicholas Piggin <npiggin@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Hui Zhu <zhuhui@kylinos.cn>
Subject: [PATCH] vmalloc: Fix NULL pointer dereference in is_vm_area_hugepages()
Date: Fri, 29 May 2026 09:41:30 +0800 [thread overview]
Message-ID: <20260529014130.671291-1-hui.zhu@linux.dev> (raw)
From: Hui Zhu <zhuhui@kylinos.cn>
find_vm_area() can return NULL if the given address is not a valid
vmalloc area. Check the return value before dereferencing it to avoid
a kernel crash.
Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings")
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
---
include/linux/vmalloc.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 3b02c0c6b371..d87dc7f77f4e 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -265,7 +265,9 @@ static inline bool is_vm_area_hugepages(const void *addr)
* allocated in the vmalloc layer.
*/
#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
- return find_vm_area(addr)->page_order > 0;
+ struct vm_struct *area = find_vm_area(addr);
+
+ return area && area->page_order > 0;
#else
return false;
#endif
--
2.43.0
next reply other threads:[~2026-05-29 1:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-29 1:41 Hui Zhu [this message]
2026-05-29 4:54 ` [PATCH] vmalloc: Fix NULL pointer dereference in is_vm_area_hugepages() Dev Jain
2026-06-01 9:29 ` Uladzislau Rezki
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