proc: check vma->vm_file before dereferencing

[~andy/linux] / fs / proc / base.c

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 3c231adf845088ee51517c1f7fd0745284d88be2..9e28356a959a2f4f0aecddd6170ebacfa799a5b3 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1877,8 +1877,9 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
        if (!vma)
                goto out_no_vma;
 
-       result = proc_map_files_instantiate(dir, dentry, task,
-                       (void *)(unsigned long)vma->vm_file->f_mode);
+       if (vma->vm_file)
+               result = proc_map_files_instantiate(dir, dentry, task,
+                               (void *)(unsigned long)vma->vm_file->f_mode);
 
 out_no_vma:
        up_read(&mm->mmap_sem);