This is a note to let you know that I've just added the patch titled

scsi: libsas: fix length error in sas_smp_handler()

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: scsi-libsas-fix-length-error-in-sas_smp_handler.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 621f6401fdeefe96dfe9eab4b167c7c39f552bb0 Mon Sep 17 00:00:00 2001

From: Jason Yan yanaijie@huawei.com Date: Mon, 11 Dec 2017 15:03:33 +0800 Subject: scsi: libsas: fix length error in sas_smp_handler()

From: Jason Yan yanaijie@huawei.com

commit 621f6401fdeefe96dfe9eab4b167c7c39f552bb0 upstream.

The return value of smp_execute_task_sg() is the untransferred residual, but bsg_job_done() requires the length of payload received. This makes SMP passthrough commands from userland by sg ioctl to libsas get a wrong response. The userland tools such as smp_utils failed because of these wrong responses:

~#smp_discover /dev/bsg/expander-2:13 response too short, len=0 ~#smp_discover /dev/bsg/expander-2:134 response too short, len=0

Fix this by passing the actual received length to bsg_job_done(). And if smp_execute_task_sg() returns 0, this means received length is exactly the buffer length.

[mkp: typo]

Fixes: 651a01364994 ("scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough") Signed-off-by: Jason Yan yanaijie@huawei.com Reported-by: chenqilin chenqilin2@huawei.com Tested-by: chenqilin chenqilin2@huawei.com CC: Christoph Hellwig hch@lst.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/scsi/libsas/sas_expander.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -2145,7 +2145,7 @@ void sas_smp_handler(struct bsg_job *job struct sas_rphy *rphy) { struct domain_device *dev; - unsigned int reslen = 0; + unsigned int rcvlen = 0; int ret = -EINVAL;

/* no rphy means no smp target support (ie aic94xx host) */ @@ -2179,12 +2179,12 @@ void sas_smp_handler(struct bsg_job *job

ret = smp_execute_task_sg(dev, job->request_payload.sg_list, job->reply_payload.sg_list); - if (ret > 0) { - /* positive number is the untransferred residual */ - reslen = ret; + if (ret >= 0) { + /* bsg_job_done() requires the length received */ + rcvlen = job->reply_payload.payload_len - ret; ret = 0; }

out: - bsg_job_done(job, ret, reslen); + bsg_job_done(job, ret, rcvlen); }

Patches currently in stable-queue which might be from yanaijie@huawei.com are

queue-4.14/scsi-libsas-fix-length-error-in-sas_smp_handler.patch