From 401f63716ca0bca1728e55ccf2132fb3785cf5da Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Tue, 31 Jan 2012 17:14:38 +0100
Subject: proc: mem_release() should check mm != NULL
commit 71879d3cb3dd8f2dfdefb252775c1b3ea04a3dd4 upstream.
mem_release() can hit mm == NULL, add the necessary check.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/proc/base.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 7b28f27ad80..b3e298f2942 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -886,8 +886,8 @@ loff_t mem_lseek(struct file *file, loff_t offset, int orig)
static int mem_release(struct inode *inode, struct file *file)
{
struct mm_struct *mm = file->private_data;
-
- mmput(mm);
+ if (mm)
+ mmput(mm);
return 0;
}
--
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