[PATCH 4.4 39/91] scsi: csiostor: Avoid content leaks and casts

Greg Kroah-Hartman
2018-12-11T16:19:01Z

From: Kees Cook <keescook@chromium.org>

commit 42c335f7e67029d2e01711f2f2bc6252277c8993 upstream.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/csiostor/csio_lnode.c | 43 ++++++++++++++++++++++---------------
1 file changed, 26 insertions(+), 17 deletions(-)

--- 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
}

static inline void
-csio_append_attrib(uint8_t **ptr, uint16_t type, uint8_t *val, uint16_t len)
+csio_append_attrib(uint8_t **ptr, uint16_t type, void *val, size_t val_len)
{
+ uint16_t len;
struct fc_fdmi_attr_entry *ae = (struct fc_fdmi_attr_entry *)*ptr;
+
+ if (WARN_ON(val_len > U16_MAX))
+ return;
+
+ len = val_len;
+
ae->type = htons(type);
len += 4; /* includes attribute type and length */
len = (len + 3) & ~3; /* should be multiple of 4 bytes */
ae->len = 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 += len;
}

@@ -335,7 +344,7 @@ csio_ln_fdmi_rhba_cbfn(struct csio_hw *h
numattrs++;
val = 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++;

@@ -346,23 +355,22 @@ csio_ln_fdmi_rhba_cbfn(struct csio_hw *h
else
val = 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++;

mfs = 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++;

strcpy(buf, "csiostor");
csio_append_attrib(&pld, FC_FDMI_PORT_ATTR_OSDEVICENAME, buf,
- (uint16_t)strlen(buf));
+ strlen(buf));
numattrs++;

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 = htonl(numattrs);
@@ -444,33 +452,32 @@ csio_ln_fdmi_dprt_cbfn(struct csio_hw *h

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++;

if (!csio_osname(buf, sizeof(buf))) {
csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_OSNAMEVERSION,
- buf, (uint16_t)strlen(buf));
+ buf, strlen(buf));
numattrs++;
}

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 = (uint32_t)(pld - (uint8_t *)cmd);
numattrs++;
attrib_blk->numattrs = htonl(numattrs);
@@ -1794,6 +1801,8 @@ csio_ln_mgmt_submit_req(struct csio_iore
struct csio_mgmtm *mgmtm = csio_hw_to_mgmtm(hw);
int rv;

+ BUG_ON(pld_len > pld->len);
+
io_req->io_cbfn = io_cbfn; /* Upper layer callback handler */
io_req->fw_handle = (uintptr_t) (io_req);
io_req->eq_idx = mgmtm->eq_idx;