diff mbox series

scsi: libfc: replace deprecated strncpy with memcpy

Message ID 20231030-strncpy-drivers-scsi-libfc-fc_encode-h-v1-1-c08c2be6befa@google.com (mailing list archive)
State Changes Requested
Headers show
Series scsi: libfc: replace deprecated strncpy with memcpy | expand

Commit Message

Justin Stitt Oct. 30, 2023, 10:36 p.m. UTC 
strncpy() is deprecated [1] and as such we should use different apis to
copy string data.

We can see that ct is NUL-initialized with fc_ct_hdr_fill:
|       ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rspn) + len,
...

In fc_ct_hdr_fill():
|       memset(ct, 0, ct_plen);

We also calculate the length of the source string:
|       len = strnlen(fc_host_symbolic_name(lport->host), 255);

then this argument is used in strncpy(), which is bad because the
pattern of (dest, src, strlen(src)) usually leaves the destination
buffer without NUL-termination. However, this seems to be correct in
this instance since fr_name is part of a seq_buf-like structure
monitoring the length:
|       struct fc_ns_rspn {
|       	struct fc_ns_fid fr_fid;	/* port ID object */
|       	__u8		fr_name_len;
|       	char		fr_name[];
|       } __attribute__((__packed__));

So, this is really just a byte copy into a length-bounded string. Let's
use memcpy() and mark the buffers as __nonstring.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.

Found with: $ rg "strncpy\("
---
 drivers/scsi/libfc/fc_encode.h | 8 ++++----
 include/uapi/scsi/fc/fc_ns.h   | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)


---
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
change-id: 20231030-strncpy-drivers-scsi-libfc-fc_encode-h-5ad629f6de9c

Best regards,
--
Justin Stitt <justinstitt@google.com>

Comments

kernel test robot Nov. 2, 2023, 3:03 p.m. UTC | #1 
Hi Justin,

kernel test robot noticed the following build warnings:

[auto build test WARNING on ffc253263a1375a65fa6c9f62a893e9767fbebfa]

url:    https://github.com/intel-lab-lkp/linux/commits/Justin-Stitt/scsi-libfc-replace-deprecated-strncpy-with-memcpy/20231031-063815
base:   ffc253263a1375a65fa6c9f62a893e9767fbebfa
patch link:    https://lore.kernel.org/r/20231030-strncpy-drivers-scsi-libfc-fc_encode-h-v1-1-c08c2be6befa%40google.com
patch subject: [PATCH] scsi: libfc: replace deprecated strncpy with memcpy
config: s390-defconfig (https://download.01.org/0day-ci/archive/20231102/202311022256.mWiYJshd-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231102/202311022256.mWiYJshd-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311022256.mWiYJshd-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In function 'zfcp_fc_gspn',
       inlined from 'zfcp_fc_sym_name_update' at drivers/s390/scsi/zfcp_fc.c:951:8:
>> drivers/s390/scsi/zfcp_fc.c:877:15: warning: 'strstr' argument 1 declared attribute 'nonstring' [-Wstringop-overread]
     877 |             !(strstr(gspn_rsp->gspn.fp_name, devno)))
         |              ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/scsi/libfc.h:21,
                    from drivers/s390/scsi/zfcp_fc.c:19:
   include/uapi/scsi/fc/fc_ns.h: In function 'zfcp_fc_sym_name_update':
   include/uapi/scsi/fc/fc_ns.h:148:17: note: argument 'fp_name' declared here
     148 |         char    fp_name[] __nonstring;
         |                 ^~~~~~~


vim +877 drivers/s390/scsi/zfcp_fc.c

cc8c282963bd25 Swen Schillig    2008-06-10  844  
038d9446a9e601 Christof Schmitt 2011-02-22  845  static int zfcp_fc_gspn(struct zfcp_adapter *adapter,
038d9446a9e601 Christof Schmitt 2011-02-22  846  			struct zfcp_fc_req *fc_req)
038d9446a9e601 Christof Schmitt 2011-02-22  847  {
038d9446a9e601 Christof Schmitt 2011-02-22  848  	DECLARE_COMPLETION_ONSTACK(completion);
038d9446a9e601 Christof Schmitt 2011-02-22  849  	char devno[] = "DEVNO:";
038d9446a9e601 Christof Schmitt 2011-02-22  850  	struct zfcp_fsf_ct_els *ct_els = &fc_req->ct_els;
038d9446a9e601 Christof Schmitt 2011-02-22  851  	struct zfcp_fc_gspn_req *gspn_req = &fc_req->u.gspn.req;
038d9446a9e601 Christof Schmitt 2011-02-22  852  	struct zfcp_fc_gspn_rsp *gspn_rsp = &fc_req->u.gspn.rsp;
038d9446a9e601 Christof Schmitt 2011-02-22  853  	int ret;
038d9446a9e601 Christof Schmitt 2011-02-22  854  
038d9446a9e601 Christof Schmitt 2011-02-22  855  	zfcp_fc_ct_ns_init(&gspn_req->ct_hdr, FC_NS_GSPN_ID,
038d9446a9e601 Christof Schmitt 2011-02-22  856  			   FC_SYMBOLIC_NAME_SIZE);
038d9446a9e601 Christof Schmitt 2011-02-22  857  	hton24(gspn_req->gspn.fp_fid, fc_host_port_id(adapter->scsi_host));
038d9446a9e601 Christof Schmitt 2011-02-22  858  
038d9446a9e601 Christof Schmitt 2011-02-22  859  	sg_init_one(&fc_req->sg_req, gspn_req, sizeof(*gspn_req));
038d9446a9e601 Christof Schmitt 2011-02-22  860  	sg_init_one(&fc_req->sg_rsp, gspn_rsp, sizeof(*gspn_rsp));
038d9446a9e601 Christof Schmitt 2011-02-22  861  
038d9446a9e601 Christof Schmitt 2011-02-22  862  	ct_els->handler = zfcp_fc_complete;
038d9446a9e601 Christof Schmitt 2011-02-22  863  	ct_els->handler_data = &completion;
038d9446a9e601 Christof Schmitt 2011-02-22  864  	ct_els->req = &fc_req->sg_req;
038d9446a9e601 Christof Schmitt 2011-02-22  865  	ct_els->resp = &fc_req->sg_rsp;
038d9446a9e601 Christof Schmitt 2011-02-22  866  
038d9446a9e601 Christof Schmitt 2011-02-22  867  	ret = zfcp_fsf_send_ct(&adapter->gs->ds, ct_els, NULL,
038d9446a9e601 Christof Schmitt 2011-02-22  868  			       ZFCP_FC_CTELS_TMO);
038d9446a9e601 Christof Schmitt 2011-02-22  869  	if (ret)
038d9446a9e601 Christof Schmitt 2011-02-22  870  		return ret;
038d9446a9e601 Christof Schmitt 2011-02-22  871  
038d9446a9e601 Christof Schmitt 2011-02-22  872  	wait_for_completion(&completion);
038d9446a9e601 Christof Schmitt 2011-02-22  873  	if (ct_els->status)
038d9446a9e601 Christof Schmitt 2011-02-22  874  		return ct_els->status;
038d9446a9e601 Christof Schmitt 2011-02-22  875  
038d9446a9e601 Christof Schmitt 2011-02-22  876  	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_NPIV &&
038d9446a9e601 Christof Schmitt 2011-02-22 @877  	    !(strstr(gspn_rsp->gspn.fp_name, devno)))
038d9446a9e601 Christof Schmitt 2011-02-22  878  		snprintf(fc_host_symbolic_name(adapter->scsi_host),
038d9446a9e601 Christof Schmitt 2011-02-22  879  			 FC_SYMBOLIC_NAME_SIZE, "%s%s %s NAME: %s",
038d9446a9e601 Christof Schmitt 2011-02-22  880  			 gspn_rsp->gspn.fp_name, devno,
038d9446a9e601 Christof Schmitt 2011-02-22  881  			 dev_name(&adapter->ccw_device->dev),
038d9446a9e601 Christof Schmitt 2011-02-22  882  			 init_utsname()->nodename);
038d9446a9e601 Christof Schmitt 2011-02-22  883  	else
820109fb11f24b Wolfram Sang     2022-08-18  884  		strscpy(fc_host_symbolic_name(adapter->scsi_host),
038d9446a9e601 Christof Schmitt 2011-02-22  885  			gspn_rsp->gspn.fp_name, FC_SYMBOLIC_NAME_SIZE);
038d9446a9e601 Christof Schmitt 2011-02-22  886  
038d9446a9e601 Christof Schmitt 2011-02-22  887  	return 0;
038d9446a9e601 Christof Schmitt 2011-02-22  888  }
038d9446a9e601 Christof Schmitt 2011-02-22  889
kernel test robot Nov. 2, 2023, 11:10 p.m. UTC | #2 
Hi Justin,

kernel test robot noticed the following build errors:

[auto build test ERROR on ffc253263a1375a65fa6c9f62a893e9767fbebfa]

url:    https://github.com/intel-lab-lkp/linux/commits/Justin-Stitt/scsi-libfc-replace-deprecated-strncpy-with-memcpy/20231031-063815
base:   ffc253263a1375a65fa6c9f62a893e9767fbebfa
patch link:    https://lore.kernel.org/r/20231030-strncpy-drivers-scsi-libfc-fc_encode-h-v1-1-c08c2be6befa%40google.com
patch subject: [PATCH] scsi: libfc: replace deprecated strncpy with memcpy
config: i386-randconfig-141-20231102 (https://download.01.org/0day-ci/archive/20231103/202311030603.XIHsNBru-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231103/202311030603.XIHsNBru-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311030603.XIHsNBru-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from <command-line>:32:0:
>> ./usr/include/scsi/fc/fc_ns.h:148:17: error: expected ':', ',', ';', '}' or '__attribute__' before '__nonstring'
     char fp_name[] __nonstring;
                    ^~~~~~~~~~~
   ./usr/include/scsi/fc/fc_ns.h:174:18: error: expected ':', ',', ';', '}' or '__attribute__' before '__nonstring'
     char  fr_name[] __nonstring;
                     ^~~~~~~~~~~
   ./usr/include/scsi/fc/fc_ns.h:183:18: error: expected ':', ',', ';', '}' or '__attribute__' before '__nonstring'
     char  fr_name[] __nonstring;
                     ^~~~~~~~~~~
diff mbox series

Patch

diff --git a/drivers/scsi/libfc/fc_encode.h b/drivers/scsi/libfc/fc_encode.h
index 7dcac3b6baa7..ba8cc4ee650c 100644
--- a/drivers/scsi/libfc/fc_encode.h
+++ b/drivers/scsi/libfc/fc_encode.h
@@ -140,8 +140,8 @@  static inline int fc_ct_ns_fill(struct fc_lport *lport,
 		ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rspn) + len,
 				    FC_FST_DIR, FC_NS_SUBTYPE);
 		hton24(ct->payload.spn.fr_fid.fp_fid, lport->port_id);
-		strncpy(ct->payload.spn.fr_name,
-			fc_host_symbolic_name(lport->host), len);
+		memcpy(ct->payload.spn.fr_name,
+		       fc_host_symbolic_name(lport->host), len);
 		ct->payload.spn.fr_name_len = len;
 		break;
 
@@ -150,8 +150,8 @@  static inline int fc_ct_ns_fill(struct fc_lport *lport,
 		ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rsnn) + len,
 				    FC_FST_DIR, FC_NS_SUBTYPE);
 		put_unaligned_be64(lport->wwnn, &ct->payload.snn.fr_wwn);
-		strncpy(ct->payload.snn.fr_name,
-			fc_host_symbolic_name(lport->host), len);
+		memcpy(ct->payload.snn.fr_name,
+		       fc_host_symbolic_name(lport->host), len);
 		ct->payload.snn.fr_name_len = len;
 		break;
 
diff --git a/include/uapi/scsi/fc/fc_ns.h b/include/uapi/scsi/fc/fc_ns.h
index 4cf0a40a099a..8a6f6c6b5213 100644
--- a/include/uapi/scsi/fc/fc_ns.h
+++ b/include/uapi/scsi/fc/fc_ns.h
@@ -145,7 +145,7 @@  struct fc_gid_pn_resp {
  */
 struct fc_gspn_resp {
 	__u8	fp_name_len;
-	char	fp_name[];
+	char	fp_name[] __nonstring;
 };
 
 /*
@@ -171,7 +171,7 @@  struct fc_ns_rn_id {
 struct fc_ns_rsnn {
 	__be64		fr_wwn;		/* node name */
 	__u8		fr_name_len;
-	char		fr_name[];
+	char		fr_name[] __nonstring;
 } __attribute__((__packed__));
 
 /*
@@ -180,7 +180,7 @@  struct fc_ns_rsnn {
 struct fc_ns_rspn {
 	struct fc_ns_fid fr_fid;	/* port ID object */
 	__u8		fr_name_len;
-	char		fr_name[];
+	char		fr_name[] __nonstring;
 } __attribute__((__packed__));
 
 /*