proc: mem_release() should check mm != NULL

mem_release() can hit mm == NULL, add the necessary check.

Cc: stable@kernel.org
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2012-01-31 17:14:38 +01:00 committed by Linus Torvalds
parent 879a5a001b
commit 71879d3cb3

View File

@ -822,7 +822,7 @@ 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;
if (mm)
mmput(mm);
return 0;
}