From patchwork Tue May 26 12:05:57 2020
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-Patchwork-Submitter: Pratyush Yadav
X-Patchwork-Id: 246579
List-Id: U-Boot discussion
From: p.yadav at ti.com (Pratyush Yadav)
Date: Tue, 26 May 2020 17:35:57 +0530
Subject: [PATCH] regmap: Check for out-of-range offsets before mapping them
Message-ID: <20200526120557.26240-1-p.yadav@ti.com>
In regmap_raw_{read,write}_range(), offsets are checked to make sure
they aren't out of range. But this check happens _after_ the address is
mapped from physical memory. Input should be sanity-checked before using
it. Mapping the address before validating it leaves the door open to
passing an invalid address to map_physmem(). So check for out of range
offsets _before_ mapping them.
This fixes a segmentation fault in sandbox when -1 is used as an offset
to regmap_{read,write}().
Signed-off-by: Pratyush Yadav
---
drivers/core/regmap.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index 4a214eff7c..a67a237b88 100644
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -310,13 +310,13 @@ int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset,
}
range = &map->ranges[range_num];
- ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
-
if (offset + val_len > range->size) {
debug("%s: offset/size combination invalid\n", __func__);
return -ERANGE;
}
+ ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
+
switch (val_len) {
case REGMAP_SIZE_8:
*((u8 *)valp) = __read_8(ptr, map->endianness);
@@ -419,13 +419,13 @@ int regmap_raw_write_range(struct regmap *map, uint range_num, uint offset,
}
range = &map->ranges[range_num];
- ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
-
if (offset + val_len > range->size) {
debug("%s: offset/size combination invalid\n", __func__);
return -ERANGE;
}
+ ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
+
switch (val_len) {
case REGMAP_SIZE_8:
__write_8(ptr, val, map->endianness);