| From | Jiri Slaby <> | Subject | [PATCH 3.12 030/170] IB/srp: Fix a sporadic crash triggered by cable pulling | Date | Fri, 18 Jul 2014 14:10:35 +0200 |
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From: Bart Van Assche <bvanassche@acm.org>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit 024ca90151f5e4296d30f72c13ff9a075e23c9ec upstream.
Avoid that the loops that iterate over the request ring can encounter a pointer to a SCSI command in req->scmnd that is no longer associated with that request. If the function srp_unmap_data() is invoked twice for a SCSI command that is not in flight then that would cause ib_fmr_pool_unmap() to be invoked with an invalid pointer as argument, resulting in a kernel oops.
Reported-by: Sagi Grimberg <sagig@mellanox.com> Reference: http://thread.gmane.org/gmane.linux.drivers.rdma/19068/focus=19069 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- drivers/infiniband/ulp/srp/ib_srp.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 17b58f4f0681..024fa025a7ab 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -1412,6 +1412,12 @@ err_unmap: err_iu: srp_put_tx_iu(target, iu, SRP_IU_CMD); + /* + * Avoid that the loops that iterate over the request ring can + * encounter a dangling SCSI command pointer. + */ + req->scmnd = NULL; + spin_lock_irqsave(&target->lock, flags); list_add(&req->list, &target->free_reqs); -- 2.0.0
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