diff options
| -rw-r--r-- | drivers/char/mem.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index a33163dbb913..5bb1985ec484 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -381,6 +381,9 @@ 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; @@ -509,6 +512,9 @@ 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); |