* [PATCH AUTOSEL 4.9 095/107] mm/page_owner: clamp read count to PAGE_SIZE
[not found] <20190128161947.57405-1-sashal@kernel.org>
@ 2019-01-28 16:19 ` Sasha Levin
2019-01-28 16:19 ` Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2019-01-28 16:19 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Miles Chen, Joe Perches, Matthew Wilcox, Andrew Morton,
Linus Torvalds, Sasha Levin, linux-mm
From: Miles Chen <miles.chen@mediatek.com>
[ Upstream commit c8f61cfc871fadfb73ad3eacd64fda457279e911 ]
The (root-only) page owner read might allocate a large size of memory with
a large read count. Allocation fails can easily occur when doing high
order allocations.
Clamp buffer size to PAGE_SIZE to avoid arbitrary size allocation
and avoid allocation fails due to high order allocation.
[akpm@linux-foundation.org: use min_t()]
Link: http://lkml.kernel.org/r/1541091607-27402-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/page_owner.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 60634dc53a88..f3e527d95ab6 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -334,6 +334,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
.skip = 0
};
+ count = min_t(size_t, count, PAGE_SIZE);
kbuf = kmalloc(count, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
--
2.19.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 4.9 095/107] mm/page_owner: clamp read count to PAGE_SIZE
2019-01-28 16:19 ` [PATCH AUTOSEL 4.9 095/107] mm/page_owner: clamp read count to PAGE_SIZE Sasha Levin
@ 2019-01-28 16:19 ` Sasha Levin
0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2019-01-28 16:19 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Miles Chen, Joe Perches, Matthew Wilcox, Andrew Morton,
Linus Torvalds, Sasha Levin, linux-mm
From: Miles Chen <miles.chen@mediatek.com>
[ Upstream commit c8f61cfc871fadfb73ad3eacd64fda457279e911 ]
The (root-only) page owner read might allocate a large size of memory with
a large read count. Allocation fails can easily occur when doing high
order allocations.
Clamp buffer size to PAGE_SIZE to avoid arbitrary size allocation
and avoid allocation fails due to high order allocation.
[akpm@linux-foundation.org: use min_t()]
Link: http://lkml.kernel.org/r/1541091607-27402-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/page_owner.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 60634dc53a88..f3e527d95ab6 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -334,6 +334,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
.skip = 0
};
+ count = min_t(size_t, count, PAGE_SIZE);
kbuf = kmalloc(count, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
--
2.19.1
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-01-28 16:19 ` [PATCH AUTOSEL 4.9 095/107] mm/page_owner: clamp read count to PAGE_SIZE Sasha Levin
2019-01-28 16:19 ` Sasha Levin
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