[Devel] [PATCH] proc: check vma->vm_file before dereferencing

[Stanislav Kinsbursky]

It can be equal to NULL.

Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>
---
 fs/proc/base.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 144a967..74fc562 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1770,8 +1770,9 @@ 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);