* [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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