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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Kees Cook <keescook@chromium.org>,
        Daniel Micay <danielmicay@gmail.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.9 050/293] scsi: csiostor: Avoid content leaks
 and casts
Thread-Topic: [PATCH AUTOSEL for 4.9 050/293] scsi: csiostor: Avoid content
 leaks and casts
Thread-Index: AQHTz5j7Ov/h/F4C+0aasIraEihH7g==
Date:   Mon, 9 Apr 2018 00:23:29 +0000
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References: <20180409002239.163177-1-alexander.levin@microsoft.com>
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From: Kees Cook <keescook@chromium.org>

[ Upstream commit 42c335f7e67029d2e01711f2f2bc6252277c8993 ]

When copying attributes, the len argument was padded out and the
resulting memcpy() would copy beyond the end of the source buffer.
Avoid this, and use size_t for val_len to avoid all the casts.
Similarly, avoid source buffer casts and use void *.

Additionally enforces val_len can be represented by u16 and that the DMA
buffer was not overflowed. Fixes the size of mfa, which is not
FC_FDMI_PORT_ATTR_MAXFRAMESIZE_LEN (but it will be padded up to 4). This
was noticed by the future CONFIG_FORTIFY_SOURCE checks.

Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/scsi/csiostor/csio_lnode.c | 43 +++++++++++++++++++++++-----------=
----
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/csiostor/csio_lnode.c b/drivers/scsi/csiostor/csi=
o_lnode.c
index c00b2ff72b55..be5ee2d37815 100644
--- a/drivers/scsi/csiostor/csio_lnode.c
+++ b/drivers/scsi/csiostor/csio_lnode.c
@@ -238,14 +238,23 @@ csio_osname(uint8_t *buf, size_t buf_len)
 }
=20
 static inline void
-csio_append_attrib(uint8_t **ptr, uint16_t type, uint8_t *val, uint16_t le=
n)
+csio_append_attrib(uint8_t **ptr, uint16_t type, void *val, size_t val_len=
)
 {
+	uint16_t len;
 	struct fc_fdmi_attr_entry *ae =3D (struct fc_fdmi_attr_entry *)*ptr;
+
+	if (WARN_ON(val_len > U16_MAX))
+		return;
+
+	len =3D val_len;
+
 	ae->type =3D htons(type);
 	len +=3D 4;		/* includes attribute type and length */
 	len =3D (len + 3) & ~3;	/* should be multiple of 4 bytes */
 	ae->len =3D htons(len);
-	memcpy(ae->value, val, len);
+	memcpy(ae->value, val, val_len);
+	if (len > val_len)
+		memset(ae->value + val_len, 0, len - val_len);
 	*ptr +=3D len;
 }
=20
@@ -335,7 +344,7 @@ csio_ln_fdmi_rhba_cbfn(struct csio_hw *hw, struct csio_=
ioreq *fdmi_req)
 	numattrs++;
 	val =3D htonl(FC_PORTSPEED_1GBIT | FC_PORTSPEED_10GBIT);
 	csio_append_attrib(&pld, FC_FDMI_PORT_ATTR_SUPPORTEDSPEED,
-			   (uint8_t *)&val,
+			   &val,
 			   FC_FDMI_PORT_ATTR_SUPPORTEDSPEED_LEN);
 	numattrs++;
=20
@@ -346,23 +355,22 @@ csio_ln_fdmi_rhba_cbfn(struct csio_hw *hw, struct csi=
o_ioreq *fdmi_req)
 	else
 		val =3D htonl(CSIO_HBA_PORTSPEED_UNKNOWN);
 	csio_append_attrib(&pld, FC_FDMI_PORT_ATTR_CURRENTPORTSPEED,
-			   (uint8_t *)&val,
-			   FC_FDMI_PORT_ATTR_CURRENTPORTSPEED_LEN);
+			   &val, FC_FDMI_PORT_ATTR_CURRENTPORTSPEED_LEN);
 	numattrs++;
=20
 	mfs =3D ln->ln_sparm.csp.sp_bb_data;
 	csio_append_attrib(&pld, FC_FDMI_PORT_ATTR_MAXFRAMESIZE,
-			   (uint8_t *)&mfs, FC_FDMI_PORT_ATTR_MAXFRAMESIZE_LEN);
+			   &mfs, sizeof(mfs));
 	numattrs++;
=20
 	strcpy(buf, "csiostor");
 	csio_append_attrib(&pld, FC_FDMI_PORT_ATTR_OSDEVICENAME, buf,
-			   (uint16_t)strlen(buf));
+			   strlen(buf));
 	numattrs++;
=20
 	if (!csio_hostname(buf, sizeof(buf))) {
 		csio_append_attrib(&pld, FC_FDMI_PORT_ATTR_HOSTNAME,
-				   buf, (uint16_t)strlen(buf));
+				   buf, strlen(buf));
 		numattrs++;
 	}
 	attrib_blk->numattrs =3D htonl(numattrs);
@@ -444,33 +452,32 @@ csio_ln_fdmi_dprt_cbfn(struct csio_hw *hw, struct csi=
o_ioreq *fdmi_req)
=20
 	strcpy(buf, "Chelsio Communications");
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_MANUFACTURER, buf,
-			   (uint16_t)strlen(buf));
+			   strlen(buf));
 	numattrs++;
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_SERIALNUMBER,
-			   hw->vpd.sn, (uint16_t)sizeof(hw->vpd.sn));
+			   hw->vpd.sn, sizeof(hw->vpd.sn));
 	numattrs++;
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_MODEL, hw->vpd.id,
-			   (uint16_t)sizeof(hw->vpd.id));
+			   sizeof(hw->vpd.id));
 	numattrs++;
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_MODELDESCRIPTION,
-			   hw->model_desc, (uint16_t)strlen(hw->model_desc));
+			   hw->model_desc, strlen(hw->model_desc));
 	numattrs++;
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_HARDWAREVERSION,
-			   hw->hw_ver, (uint16_t)sizeof(hw->hw_ver));
+			   hw->hw_ver, sizeof(hw->hw_ver));
 	numattrs++;
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_FIRMWAREVERSION,
-			   hw->fwrev_str, (uint16_t)strlen(hw->fwrev_str));
+			   hw->fwrev_str, strlen(hw->fwrev_str));
 	numattrs++;
=20
 	if (!csio_osname(buf, sizeof(buf))) {
 		csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_OSNAMEVERSION,
-				   buf, (uint16_t)strlen(buf));
+				   buf, strlen(buf));
 		numattrs++;
 	}
=20
 	csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_MAXCTPAYLOAD,
-			   (uint8_t *)&maxpayload,
-			   FC_FDMI_HBA_ATTR_MAXCTPAYLOAD_LEN);
+			   &maxpayload, FC_FDMI_HBA_ATTR_MAXCTPAYLOAD_LEN);
 	len =3D (uint32_t)(pld - (uint8_t *)cmd);
 	numattrs++;
 	attrib_blk->numattrs =3D htonl(numattrs);
@@ -1794,6 +1801,8 @@ csio_ln_mgmt_submit_req(struct csio_ioreq *io_req,
 	struct csio_mgmtm *mgmtm =3D csio_hw_to_mgmtm(hw);
 	int rv;
=20
+	BUG_ON(pld_len > pld->len);
+
 	io_req->io_cbfn =3D io_cbfn;	/* Upper layer callback handler */
 	io_req->fw_handle =3D (uintptr_t) (io_req);
 	io_req->eq_idx =3D mgmtm->eq_idx;
--=20
2.15.1