Commit 0d8675e1 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Linus Walleij
Browse files

pinctrl: Duplicate user memory in one go in pinmux_select() 



Current code is suboptimal in three ways:
1) it explicitly terminates the string which is not needed;
2) it might provoke additional faults, because asked lenght might be
   bigger than the real one;
3) it consumes more than needed lines in the source.

Instead of using kmalloc() + strncpy_from_user() + terminating, just
utilize memdup_user_nul().

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230604131215.78847-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 5cc9525b

drivers/pinctrl/pinmux.c

+3 −8
Original line number Diff line number Diff line
@@ -692,14 +692,9 @@ static ssize_t pinmux_select(struct file *file, const char __user *user_buf, 
	if (len > PINMUX_SELECT_MAX)

		return -ENOMEM;



	buf = kzalloc(PINMUX_SELECT_MAX, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	ret = strncpy_from_user(buf, user_buf, PINMUX_SELECT_MAX);

	if (ret < 0)

		goto exit_free_buf;

	buf[len-1] = '\0';

	buf = memdup_user_nul(user_buf, len);

	if (IS_ERR(buf))

		return PTR_ERR(buf);



	/* remove leading and trailing spaces of input buffer */

	gname = strstrip(buf);