thinkpad-acpi: restrict procfs count value to sane upper limit

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 27d68e719e90..18f9ee63c50a 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -766,6 +766,8 @@ static int dispatch_procfs_write(struct file *file,
 
         if (!ibm || !ibm->write)
                 return -EINVAL;
+        if (count > PAGE_SIZE - 2)
+                return -EINVAL;
 
         kernbuf = kmalloc(count + 2, GFP_KERNEL);
         if (!kernbuf)