Re: [PATCH 6/6] Integrity: IMA file free imbalance

From: Mimi Zohar
Date: Mon Feb 02 2009 - 20:28:19 EST


On Mon, 2009-02-02 at 17:47 -0600, Serge E. Hallyn wrote:
> Quoting Mimi Zohar (zohar@xxxxxxxxxxxxxxxxxx):
> > The number of calls to ima_path_check()/ima_file_free()
> > should be balanced. An extra call to fput(), indicates
> > the file could have been accessed without first being
> > measured.
> >
> > Although f_count is incremented/decremented in places other
> > than fget/fput, like fget_light/fput_light and get_file, the
> > current task must already hold a file refcnt. The call to
> > __fput() is delayed until the refcnt becomes 0, resulting
> > in ima_file_free() flagging any changes.
> >
> > - add hook to increment opencount for IPC shared memory(SYSV)
> > and shmat files
> >
> > Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxx>
>
> ...
>
> > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
>
> ...
>
> > +static void opencount_get(struct file *file)
> > +{
> > + struct inode *inode = file->f_dentry->d_inode;
> > + struct ima_iint_cache *iint;
> > +
> > + if (!ima_initialized || !S_ISREG(inode->i_mode))
> > + return;
> > + iint = ima_iint_find_insert_get(inode);
> > + mutex_lock(&iint->mutex);
> > + if (iint)
>
> Hey, I think you've got those two lines above mixed
> up a bit :)

yes, thanks!

> Very neat, though.
>
> Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
>
> once that's fixed up.
>
> thanks,
> -serge

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