Commit db04328c authored Dec 11, 2012 by Mark Brown

regmap: debugfs: Avoid overflows for very small reads



If count is less than the size of a register then we may hit integer
wraparound when trying to move backwards to check if we're still in
the buffer. Instead move the position forwards to check if it's still
in the buffer, we are unlikely to be able to allocate a buffer
sufficiently big to overflow here.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

parent cbc1938b

drivers/base/regmap/regmap-debugfs.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -93,7 +93,7 @@ static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
		/* If we're in the region the user is trying to read */
		if (p >= *ppos) {
		/* ...but not beyond it */
		if (buf_pos >= count - 1 - map->debugfs_tot_len)
		if (buf_pos + 1 + map->debugfs_tot_len >= count)
		break;

		/* Format the register */