Merge branch 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6

[firefly-linux-kernel-4.4.55.git] / mm / nommu.c

diff --git a/mm/nommu.c b/mm/nommu.c
index 53cab10fece40a3f5835604e62754818de0e1e7c..4bde489ec4316ca41046f5826f3a57565755d90d 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -69,9 +69,6 @@ int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
 int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
 int heap_stack_gap = 0;
 
-/* amount of vm to protect from userspace access */
-unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
-
 atomic_long_t mmap_pages_allocated;
 
 EXPORT_SYMBOL(mem_map);
@@ -922,6 +919,10 @@ static int validate_mmap_request(struct file *file,
                if (!file->f_op->read)
                        capabilities &= ~BDI_CAP_MAP_COPY;
 
+               /* The file shall have been opened with read permission. */
+               if (!(file->f_mode & FMODE_READ))
+                       return -EACCES;
+
                if (flags & MAP_SHARED) {
                        /* do checks for writing, appending and locking */
                        if ((prot & PROT_WRITE) &&