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path: root/drivers/char/mem.c
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Diffstat (limited to 'drivers/char/mem.c')
-rw-r--r--drivers/char/mem.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 5bb1985ec484..6d9cc2d39d22 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -381,9 +381,6 @@ static ssize_t read_kmem(struct file *file, char __user *buf,
char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
int err = 0;
- if (!pfn_valid(PFN_DOWN(p)))
- return -EIO;
-
read = 0;
if (p < (unsigned long) high_memory) {
low_count = count;
@@ -412,6 +409,8 @@ static ssize_t read_kmem(struct file *file, char __user *buf,
* by the kernel or data corruption may occur
*/
kbuf = xlate_dev_kmem_ptr((void *)p);
+ if (!virt_addr_valid(kbuf))
+ return -ENXIO;
if (copy_to_user(buf, kbuf, sz))
return -EFAULT;
@@ -482,6 +481,8 @@ static ssize_t do_write_kmem(unsigned long p, const char __user *buf,
* corruption may occur.
*/
ptr = xlate_dev_kmem_ptr((void *)p);
+ if (!virt_addr_valid(ptr))
+ return -ENXIO;
copied = copy_from_user(ptr, buf, sz);
if (copied) {
@@ -512,9 +513,6 @@ static ssize_t write_kmem(struct file *file, const char __user *buf,
char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
int err = 0;
- if (!pfn_valid(PFN_DOWN(p)))
- return -EIO;
-
if (p < (unsigned long) high_memory) {
unsigned long to_write = min_t(unsigned long, count,
(unsigned long)high_memory - p);