From: Bart Van Assche Date: Tue, 20 May 2014 13:03:49 +0000 (+0200) Subject: IB/srp: Fix a sporadic crash triggered by cable pulling X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1ebc929e0e5c4bae8f02701ce017f331ae27a19a;p=karo-tx-linux.git IB/srp: Fix a sporadic crash triggered by cable pulling 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 Reference: http://thread.gmane.org/gmane.linux.drivers.rdma/19068/focus=19069 Signed-off-by: Bart Van Assche Reviewed-by: Sagi Grimberg Signed-off-by: Roland Dreier Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 529b6bcdca7a..e96c07ee6756 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -1576,6 +1576,12 @@ 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);