Commit 37bd59d3 authored by Dan Carpenter's avatar Dan Carpenter Committed by Hans de Goede
Browse files

platform/x86: intel_pmc_core: Uninitialized data in pmc_core_lpm_latch_mode_write() 



The simple_write_to_buffer() can return success if even a single byte
is copied from user space.  In this case it can result in using
uninitalized data if the buf[] array is not fully initialized.  Really
we should only succeed if the whole buffer is copied.

Just using copy_from_user() is simpler and more appropriate.

Fixes: 8074a79f ("platform/x86: intel_pmc_core: Add option to set/clear LPM mode")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YIBCf+G9Ef8wrGJw@mwanda


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent f75bf693

drivers/platform/x86/intel_pmc_core.c

+2 −6
Original line number Diff line number Diff line
@@ -1360,17 +1360,13 @@ static ssize_t pmc_core_lpm_latch_mode_write(struct file *file, 
	struct pmc_dev *pmcdev = s->private;

	bool clear = false, c10 = false;

	unsigned char buf[8];

	ssize_t ret;

	int idx, m, mode;

	u32 reg;



	if (count > sizeof(buf) - 1)

		return -EINVAL;



	ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf, count);

	if (ret < 0)

		return ret;



	if (copy_from_user(buf, userbuf, count))

		return -EFAULT;

	buf[count] = '\0';



	/*