Messages in this thread | | | Subject | Re: [PATCH] RDS: fix race condition when sending a message on unbound socket. | From | santosh shilimkar <> | Date | Tue, 24 Nov 2015 10:43:29 -0800 |
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On 11/24/2015 10:25 AM, Ben Hutchings wrote: > On Tue, 2015-11-03 at 12:25 +0100, Quentin Casasnovas wrote: >> On Fri, Oct 16, 2015 at 10:47:49AM -0700, santosh shilimkar wrote: >>> 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") >>>> >> >> For reference, this has been assigned CVE-2015-7990 on the oss-sec thread: >> >> http://seclists.org/oss-sec/2015/q4/179 > > But the patch doesn't seem to have gone anywhere. Santosh, can you > apply this in your tree and ask David to pull, or should Quentin re- > send it to netdev? > Indeed, its not picked up yet. I will send the refreshed patch for Dave to pull. Thanks for reporting Ben.
Regards, Santosh
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