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 28754c40be986608e96fe3cb1db7111a6e161cf8..4bde489ec4316ca41046f5826f3a57565755d90d 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -919,6 +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) &&