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From:   Mike Rapoport <rppt@kernel.org>
To:     linux-arm-kernel@lists.infradead.org
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Mike Rapoport <rppt@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Tony Lindgren <tony@atomide.com>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: [PATCH v3 3/4] memblock: ensure there is no overflow in memblock_overlaps_region()
Date:   Wed, 30 Jun 2021 10:12:10 +0300
Message-Id: <20210630071211.21011-4-rppt@kernel.org>
In-Reply-To: <20210630071211.21011-1-rppt@kernel.org>
References: <20210630071211.21011-1-rppt@kernel.org>
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From: Mike Rapoport <rppt@linux.ibm.com>

There maybe an overflow in memblock_overlaps_region() if it is called with
base and size such that

	base + size > PHYS_ADDR_MAX

Make sure that memblock_overlaps_region() caps the size to prevent such
overflow and remove now duplicated call to memblock_cap_size() from
memblock_is_region_reserved().

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 mm/memblock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 2e25d69739e0..67e0e24f8cc9 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -182,6 +182,8 @@ bool __init_memblock memblock_overlaps_region(struct memblock_type *type,
 {
 	unsigned long i;
 
+	memblock_cap_size(base, &size);
+
 	for (i = 0; i < type->cnt; i++)
 		if (memblock_addrs_overlap(base, size, type->regions[i].base,
 					   type->regions[i].size))
@@ -1794,7 +1796,6 @@ bool __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t siz
  */
 bool __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
 {
-	memblock_cap_size(base, &size);
 	return memblock_overlaps_region(&memblock.reserved, base, size);
 }
 
-- 
2.28.0