From:   Mark-PK Tsai <mark-pk.tsai@mediatek.com>
To:     <stable@vger.kernel.org>
CC:     <rppt@kernel.org>, <akpm@linux-foundation.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        <linux@armlinux.org.uk>, <rppt@linux.ibm.com>, <tony@atomide.com>,
        <wangkefeng.wang@huawei.com>, <mark-pk.tsai@mediatek.com>,
        <yj.chiang@mediatek.com>
Subject: [PATCH 5.10 3/5] memblock: ensure there is no overflow in memblock_overlaps_region()
Date:   Mon, 13 Dec 2021 17:41:33 +0800
Message-ID: <20211213094135.1798-4-mark-pk.tsai@mediatek.com>
In-Reply-To: <20211213094135.1798-1-mark-pk.tsai@mediatek.com>
References: <20211213094135.1798-1-mark-pk.tsai@mediatek.com>
MIME-Version: 1.0
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From: Mike Rapoport <rppt@linux.ibm.com>

[ Upstream commit 023accf5cdc1e504a9b04187ec23ff156fe53d90 ]

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>
Tested-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/lkml/20210630071211.21011-1-rppt@kernel.org/
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
---
 mm/memblock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index c337df03b6a1..faa4de579b3d 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))
@@ -1792,7 +1794,6 @@ 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);
 }
 
-- 
2.18.0