Commit f52b31ec authored May 17, 2022 by Dan Carpenter Committed by Greg Kroah-Hartman Aug 25, 2022

wifi: rtlwifi: fix error codes in rtl_debugfs_set_write_h2c()



[ Upstream commit b88d28146c30a8e14f0f012d56ebf19b68a348f4 ]

If the copy_from_user() fails or the user gives invalid date then the
correct thing to do is to return a negative error code.  (Currently it
returns success).

I made a copy additional related cleanups:
1) There is no need to check "buffer" for NULL.  That's handled by
copy_from_user().
2) The "h2c_len" variable cannot be negative because it is unsigned
and because sscanf() does not return negative error codes.

Fixes: 610247f4 ("rtlwifi: Improve debugging by using debugfs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/YoOLnDkHgVltyXK7@kili


Signed-off-by: Sasha Levin <sashal@kernel.org>

parent c59876f8

drivers/net/wireless/realtek/rtlwifi/debug.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -349,8 +349,8 @@ static ssize_t rtl_debugfs_set_write_h2c(struct file *filp,

		tmp_len = (count > sizeof(tmp) - 1 ? sizeof(tmp) - 1 : count);

		if (!buffer \|\| copy_from_user(tmp, buffer, tmp_len))
		return count;
		if (copy_from_user(tmp, buffer, tmp_len))
		return -EFAULT;

		tmp[tmp_len] = '\0';

		@@ -360,8 +360,8 @@ static ssize_t rtl_debugfs_set_write_h2c(struct file *filp,
		&h2c_data[4], &h2c_data[5],
		&h2c_data[6], &h2c_data[7]);

		if (h2c_len <= 0)
		return count;
		if (h2c_len == 0)
		return -EINVAL;

		for (i = 0; i < h2c_len; i++)
		h2c_data_packed[i] = (u8)h2c_data[i];