Messages in this thread | | | Subject | Re: [PATCH] RDS: fix race condition when sending a message on unbound socket. | From | santosh shilimkar <> | Date | Fri, 16 Oct 2015 10:47:49 -0700 |
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On 10/16/2015 8:11 AM, Quentin Casasnovas wrote: > Sasha's found a NULL pointer dereference in the RDS connection code when > sending a message to an apparently unbound socket. The problem is caused > by the code checking if the socket is bound in rds_sendmsg(), which checks > the rs_bound_addr field without taking a lock on the socket. This opens a > race where rs_bound_addr is temporarily set but where the transport is not > in rds_bind(), leading to a NULL pointer dereference when trying to > dereference 'trans' in __rds_conn_create(). > > Vegard wrote a reproducer for this issue, so kindly ask him to share if > you're interested. > > I cannot reproduce the NULL pointer dereference using Vegard's reproducer > with this patch, whereas I could without. > > Complete earlier incomplete fix to CVE-2015-6937: > > 74e98eb08588 ("RDS: verify the underlying transport exists before creating a connection") > > Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> > Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> > Reviewed-by: Sasha Levin <sasha.levin@oracle.com> > Cc: Vegard Nossum <vegard.nossum@oracle.com> > Cc: Sasha Levin <sasha.levin@oracle.com> > Cc: Chien Yen <chien.yen@oracle.com> > Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com> > Cc: David S. Miller <davem@davemloft.net> > Cc: stable@vger.kernel.org > --- Looks right. Am glad that we got deference issue as well as the bind race fixed with it. Mail sent to Vegard for his test case which I would like to add to my tests. Thanks for the fix.
FWIW, Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
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