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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Mark Brown <broonie@kernel.org>, Markus Pargmann <mpa@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH 1/2] regmap: Fix reversed bounds check in regmap_raw_write()
Date: Thu, 8 Feb 2018 10:23:44 +0300	[thread overview]
Message-ID: <20180208072344.GA18158@mwanda> (raw)

We're supposed to be checking that "val_len" is not too large but
instead we check if it is smaller than the max.

The only function affected would be regmap_i2c_smbus_i2c_write() in
drivers/base/regmap/regmap-i2c.c.  Strangely that function has its own
limit check which returns an error if (count >= I2C_SMBUS_BLOCK_MAX) so
it doesn't look like it has ever been able to do anything except return
an error.

Fixes: c335931ed9d2 ("regmap: Add raw_write/read checks for max_raw_write/read sizes")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
This is from code review.  I can't test it.

Is it possible that there are other ways to reach
regmap_i2c_smbus_i2c_write() without going through regmap_raw_write()?
In that case, the temptation would be to just remove this check and the
one in regmap_raw_read().

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index ee302ccdfbc8..453116fd4362 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1831,7 +1831,7 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 		return -EINVAL;
 	if (val_len % map->format.val_bytes)
 		return -EINVAL;
-	if (map->max_raw_write && map->max_raw_write > val_len)
+	if (map->max_raw_write && map->max_raw_write < val_len)
 		return -E2BIG;
 
 	map->lock(map->lock_arg);

             reply	other threads:[~2018-02-08  7:23 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-08  7:23 Dan Carpenter [this message]
2018-02-08  7:25 ` [PATCH 2/2] regmap-i2c: Off by one in regmap_i2c_smbus_i2c_read/write() Dan Carpenter
2018-02-08 15:41   ` Applied "regmap-i2c: Off by one in regmap_i2c_smbus_i2c_read/write()" to the regmap tree Mark Brown
2018-02-08 15:41 ` Applied "regmap: Fix reversed bounds check in regmap_raw_write()" " Mark Brown

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