1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 92c5937f80c3..917403fe10da 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -99,6 +99,9 @@ static ssize_t read_mem(struct file *file, char __user *buf,
         ssize_t read, sz;
         char *ptr;
 
+        if (p != *ppos)
+                return 0;
+
         if (!valid_phys_addr_range(p, count))
                 return -EFAULT;
         read = 0;
@@ -157,6 +160,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf,
         unsigned long copied;
         void *ptr;
 
+        if (p != *ppos)
+                return -EFBIG;
+
         if (!valid_phys_addr_range(p, count))
                 return -EFAULT;