Message-ID: <9a2406164955ce9a1eea3f3accd33a9b9400ccca.camel@HansenPartnership.com>
Subject: [GIT PULL] SCSI fixes for 5.16-rc7
From:   James Bottomley <James.Bottomley@HansenPartnership.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     linux-scsi <linux-scsi@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
Date:   Fri, 31 Dec 2021 09:56:07 -0500
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Three fixes, all in drivers.  The lpfc one doesn't look exploitable,
but nasty things could happen in string operations if mybuf ends up
with an on stack unterminated string.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Alexey Makhalov (1):
      scsi: vmw_pvscsi: Set residual data length conditionally

Dan Carpenter (1):
      scsi: lpfc: Terminate string in lpfc_debugfs_nvmeio_trc_write()

Lixiaokeng (1):
      scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown()

And the diffstat:

 drivers/scsi/libiscsi.c          | 6 ++++--
 drivers/scsi/lpfc/lpfc_debugfs.c | 4 ++--
 drivers/scsi/vmw_pvscsi.c        | 7 +++++--
 3 files changed, 11 insertions(+), 6 deletions(-)

With full diff below.

James

---

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 284b939fb1ea..059dae8909ee 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -3100,6 +3100,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
 {
 	struct iscsi_conn *conn = cls_conn->dd_data;
 	struct iscsi_session *session = conn->session;
+	char *tmp_persistent_address = conn->persistent_address;
+	char *tmp_local_ipaddr = conn->local_ipaddr;
 
 	del_timer_sync(&conn->transport_timer);
 
@@ -3121,8 +3123,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
 	spin_lock_bh(&session->frwd_lock);
 	free_pages((unsigned long) conn->data,
 		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
-	kfree(conn->persistent_address);
-	kfree(conn->local_ipaddr);
 	/* regular RX path uses back_lock */
 	spin_lock_bh(&session->back_lock);
 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
@@ -3134,6 +3134,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
 	mutex_unlock(&session->eh_mutex);
 
 	iscsi_destroy_conn(cls_conn);
+	kfree(tmp_persistent_address);
+	kfree(tmp_local_ipaddr);
 }
 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
 
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index bd6d459afce5..08b2e85dcd7d 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -2954,8 +2954,8 @@ lpfc_debugfs_nvmeio_trc_write(struct file *file, const char __user *buf,
 	char mybuf[64];
 	char *pbuf;
 
-	if (nbytes > 64)
-		nbytes = 64;
+	if (nbytes > 63)
+		nbytes = 63;
 
 	memset(mybuf, 0, sizeof(mybuf));
 
diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
index c2ba65224633..1f037b8ab904 100644
--- a/drivers/scsi/vmw_pvscsi.c
+++ b/drivers/scsi/vmw_pvscsi.c
@@ -586,9 +586,12 @@ static void pvscsi_complete_request(struct pvscsi_adapter *adapter,
 			 * Commands like INQUIRY may transfer less data than
 			 * requested by the initiator via bufflen. Set residual
 			 * count to make upper layer aware of the actual amount
-			 * of data returned.
+			 * of data returned. There are cases when controller
+			 * returns zero dataLen with non zero data - do not set
+			 * residual count in that case.
 			 */
-			scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
+			if (e->dataLen && (e->dataLen < scsi_bufflen(cmd)))
+				scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
 			cmd->result = (DID_OK << 16);
 			break;