linux-rdma.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Divya Indi <divya.indi@oracle.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
	"Kaike Wan" <kaike.wan@intel.com>,
	"Gerd Rausch" <gerd.rausch@oracle.com>,
	"Håkon Bugge" <haakon.bugge@oracle.com>,
	"Srinivas Eeda" <srinivas.eeda@oracle.com>,
	"Rama Nichanamatlu" <rama.nichanamatlu@oracle.com>,
	"Doug Ledford" <dledford@redhat.com>,
	"Leon Romanovsky" <leon@kernel.org>
Subject: Re: [PATCH v4] IB/sa: Resolving use-after-free in ib_nl_send_msg
Date: Tue, 7 Jul 2020 18:05:02 -0700	[thread overview]
Message-ID: <d078d705-9930-7abd-84c8-9b7d41aad722@oracle.com> (raw)
In-Reply-To: <20200702190738.GA759483@nvidia.com>

Thanks Jason.

Appreciate your help and feedback for fixing this issue.

Would it be possible to access the edited version of the patch?
If yes, please share a pointer to the same.

Thanks,
Divya


On 7/2/20 12:07 PM, Jason Gunthorpe wrote:
> On Tue, Jun 23, 2020 at 07:13:09PM -0700, Divya Indi wrote:
>> Commit 3ebd2fd0d011 ("IB/sa: Put netlink request into the request list before sending")'
>> -
>> 1. Adds the query to the request list before ib_nl_snd_msg.
>> 2. Moves ib_nl_send_msg out of spinlock, hence safe to use gfp_mask as is.
>>
>> However, if there is a delay in sending out the request (For
>> eg: Delay due to low memory situation) the timer to handle request timeout
>> might kick in before the request is sent out to ibacm via netlink.
>> ib_nl_request_timeout may release the query causing a use after free situation
>> while accessing the query in ib_nl_send_msg.
>>
>> Call Trace for the above race:
>>
>> [<ffffffffa02f43cb>] ? ib_pack+0x17b/0x240 [ib_core]
>> [<ffffffffa032aef1>] ib_sa_path_rec_get+0x181/0x200 [ib_sa]
>> [<ffffffffa0379db0>] rdma_resolve_route+0x3c0/0x8d0 [rdma_cm]
>> [<ffffffffa0374450>] ? cma_bind_port+0xa0/0xa0 [rdma_cm]
>> [<ffffffffa040f850>] ? rds_rdma_cm_event_handler_cmn+0x850/0x850
>> [rds_rdma]
>> [<ffffffffa040f22c>] rds_rdma_cm_event_handler_cmn+0x22c/0x850
>> [rds_rdma]
>> [<ffffffffa040f860>] rds_rdma_cm_event_handler+0x10/0x20 [rds_rdma]
>> [<ffffffffa037778e>] addr_handler+0x9e/0x140 [rdma_cm]
>> [<ffffffffa026cdb4>] process_req+0x134/0x190 [ib_addr]
>> [<ffffffff810a02f9>] process_one_work+0x169/0x4a0
>> [<ffffffff810a0b2b>] worker_thread+0x5b/0x560
>> [<ffffffff810a0ad0>] ? flush_delayed_work+0x50/0x50
>> [<ffffffff810a68fb>] kthread+0xcb/0xf0
>> [<ffffffff816ec49a>] ? __schedule+0x24a/0x810
>> [<ffffffff816ec49a>] ? __schedule+0x24a/0x810
>> [<ffffffff810a6830>] ? kthread_create_on_node+0x180/0x180
>> [<ffffffff816f25a7>] ret_from_fork+0x47/0x90
>> [<ffffffff810a6830>] ? kthread_create_on_node+0x180/0x180
>> ....
>> RIP  [<ffffffffa03296cd>] send_mad+0x33d/0x5d0 [ib_sa]
>>
>> To resolve the above issue -
>> 1. Add the req to the request list only after the request has been sent out.
>> 2. To handle the race where response comes in before adding request to
>> the request list, send(rdma_nl_multicast) and add to list while holding the
>> spinlock - request_lock.
>> 3. Use non blocking memory allocation flags for rdma_nl_multicast since it is
>> called while holding a spinlock.
>>
>> Fixes: 3ebd2fd0d011 ("IB/sa: Put netlink request into the request list
>> before sending")
>>
>> Signed-off-by: Divya Indi <divya.indi@oracle.com>
>> ---
>> v1:
>> - Use flag IB_SA_NL_QUERY_SENT to prevent the use-after-free.
>>
>> v2:
>> - Use atomic bit ops for setting and testing IB_SA_NL_QUERY_SENT.
>> - Rewording and adding comments.
>>
>> v3:
>> - Change approach and remove usage of IB_SA_NL_QUERY_SENT.
>> - Add req to request list only after the request has been sent out.
>> - Send and add to list while holding the spinlock (request_lock).
>> - Overide gfp_mask and use GFP_NOWAIT for rdma_nl_multicast since we
>>   need non blocking memory allocation while holding spinlock.
>>
>> v4:
>> - Formatting changes.
>> - Use GFP_NOWAIT conditionally - Only when GFP_ATOMIC is not provided by caller.
>> ---
>>  drivers/infiniband/core/sa_query.c | 41 ++++++++++++++++++++++----------------
>>  1 file changed, 24 insertions(+), 17 deletions(-)
> I made a few edits, and applied to for-rc
>
> Thanks,
> Jason

  reply	other threads:[~2020-07-08  1:07 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-24  2:13 Divya Indi
2020-06-25 10:09 ` Leon Romanovsky
2020-06-25 17:11   ` Divya Indi
2020-06-25 19:00     ` Leon Romanovsky
2020-07-02 19:07 ` Jason Gunthorpe
2020-07-08  1:05   ` Divya Indi [this message]
2020-07-08  1:12     ` Jason Gunthorpe
2021-08-23 16:54       ` Haakon Bugge
2021-08-25 17:26         ` Jason Gunthorpe
2021-08-26 15:25           ` Haakon Bugge

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d078d705-9930-7abd-84c8-9b7d41aad722@oracle.com \
    --to=divya.indi@oracle.com \
    --cc=dledford@redhat.com \
    --cc=gerd.rausch@oracle.com \
    --cc=haakon.bugge@oracle.com \
    --cc=jgg@nvidia.com \
    --cc=kaike.wan@intel.com \
    --cc=leon@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=rama.nichanamatlu@oracle.com \
    --cc=srinivas.eeda@oracle.com \
    --subject='Re: [PATCH v4] IB/sa: Resolving use-after-free in ib_nl_send_msg' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).