From: Peter Zijlstra <peterz@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
jroedel@suse.de, vbabka@suse.cz, urezki@gmail.com,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH] mm/vmalloc: Sanitize __get_vm_area() arguments
Date: Fri, 3 Apr 2020 18:32:53 +0200 [thread overview]
Message-ID: <20200403163253.GU20730@hirez.programming.kicks-ass.net> (raw)
__get_vm_area() is an exported symbol, make sure the callers stay in
the expected memory range. When calling this function with memory
ranges outside of the VMALLOC range *bad* things can happen.
(I noticed this when I managed to corrupt the kernel text by accident)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
mm/vmalloc.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2130,6 +2130,13 @@ static struct vm_struct *__get_vm_area_n
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end)
{
+ /*
+ * Ensure callers stay in the vmalloc range.
+ */
+ if (WARN_ON(start < VMALLOC_START || start > VMALLOC_END ||
+ end < VMALLOC_START || end > VMALLOC_END))
+ return NULL;
+
return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
GFP_KERNEL, __builtin_return_address(0));
}
next reply other threads:[~2020-04-03 16:33 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-03 16:32 Peter Zijlstra [this message]
2020-04-03 18:18 ` [PATCH] mm/vmalloc: Sanitize __get_vm_area() arguments Uladzislau Rezki
2020-04-03 18:53 ` Peter Zijlstra
2020-04-04 19:00 ` Uladzislau Rezki
2020-04-06 13:01 ` Christoph Hellwig
2020-04-06 14:06 ` Peter Zijlstra
2020-04-17 12:57 ` Sakari Ailus
2020-04-17 13:14 ` Peter Zijlstra
2020-04-17 13:38 ` Sakari Ailus
2020-04-04 15:35 William Kucharski
2020-04-04 18:52 ` Uladzislau Rezki
2020-04-05 5:25 ` William Kucharski
2020-04-05 17:23 ` Uladzislau Rezki
2020-04-05 19:21 ` Uladzislau Rezki
2020-04-05 20:49 ` William Kucharski
2020-04-06 12:59 ` Uladzislau Rezki
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