platform/x86: thinkpad_acpi: Revert "Use strndup_user() in dispatch_proc_write()"
This reverts commit 35d13c7a05126a5a54a1ef40aff4c6984474e604.
This broke procfs interface due to neglecting the fact that
the strings are not coming NULL terminated.
Revert the change till we will have a better clean up.
Fixes: 35d13c7a0512 ("platform/x86: thinkpad_acpi: Use strndup_user() in dispatch_proc_write()")
Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index ff7f0a4..0f6fced 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -885,11 +885,19 @@
if (!ibm || !ibm->write)
return -EINVAL;
+ if (count > PAGE_SIZE - 1)
+ return -EINVAL;
- kernbuf = strndup_user(userbuf, PAGE_SIZE);
- if (IS_ERR(kernbuf))
- return PTR_ERR(kernbuf);
+ kernbuf = kmalloc(count + 1, GFP_KERNEL);
+ if (!kernbuf)
+ return -ENOMEM;
+ if (copy_from_user(kernbuf, userbuf, count)) {
+ kfree(kernbuf);
+ return -EFAULT;
+ }
+
+ kernbuf[count] = 0;
ret = ibm->write(kernbuf);
if (ret == 0)
ret = count;
