Re: [PATCH 001/190] Revert "net/rds: Avoid potential use after free in rds_send_remove_from_sock"

[Greg Kroah-Hartman]

On Tue, Apr 27, 2021 at 08:37:52PM +0200, Greg Kroah-Hartman wrote:
> On Wed, Apr 21, 2021 at 02:57:56PM +0200, Greg Kroah-Hartman wrote:
> > This reverts commit 0c85a7e87465f2d4cbc768e245f4f45b2f299b05.
> > 
> > Commits from @umn.edu addresses have been found to be submitted in "bad
> > faith" to try to test the kernel community's ability to review "known
> > malicious" changes.  The result of these submissions can be found in a
> > paper published at the 42nd IEEE Symposium on Security and Privacy
> > entitled, "Open Source Insecurity: Stealthily Introducing
> > Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> > of Minnesota) and Kangjie Lu (University of Minnesota).
> > 
> > Because of this, all submissions from this group must be reverted from
> > the kernel tree and will need to be re-reviewed again to determine if
> > they actually are a valid fix.  Until that work is complete, remove this
> > change to ensure that no problems are being introduced into the
> > codebase.
> > 
> > Cc: Aditya Pakki <pakki001@xxxxxxx>
> > Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
> > Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > ---
> >  net/rds/message.c | 1 -
> >  net/rds/send.c    | 2 +-
> >  2 files changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/net/rds/message.c b/net/rds/message.c
> > index 4fc66ff0f1ec..799034e0f513 100644
> > --- a/net/rds/message.c
> > +++ b/net/rds/message.c
> > @@ -180,7 +180,6 @@ void rds_message_put(struct rds_message *rm)
> >  		rds_message_purge(rm);
> >  
> >  		kfree(rm);
> > -		rm = NULL;
> >  	}
> >  }
> >  EXPORT_SYMBOL_GPL(rds_message_put);
> > diff --git a/net/rds/send.c b/net/rds/send.c
> > index fe5264b9d4b3..985d0b7713ac 100644
> > --- a/net/rds/send.c
> > +++ b/net/rds/send.c
> > @@ -665,7 +665,7 @@ static void rds_send_remove_from_sock(struct list_head *messages, int status)
> >  unlock_and_drop:
> >  		spin_unlock_irqrestore(&rm->m_rs_lock, flags);
> >  		rds_message_put(rm);
> > -		if (was_on_sock && rm)
> > +		if (was_on_sock)
> >  			rds_message_put(rm);
> >  	}
> >  
> > -- 
> > 2.31.1
> > 
> 
> The original, while again messy, looks ok, so I'll drop this revert.
> 
> greg k-h

Argh, no, this one has already been reverted in Linus's tree.  I've been
reviewing to many of these today, I think it's time to get some rest...

greg k-h