diff --git a/sys/dev/mfi/mfi_tbolt.c b/sys/dev/mfi/mfi_tbolt.c
index 42ce566014d6..2555f13fbe7a 100644
--- a/sys/dev/mfi/mfi_tbolt.c
+++ b/sys/dev/mfi/mfi_tbolt.c
@@ -1078,7 +1078,7 @@ mfi_tbolt_build_mpt_cmd(struct mfi_softc *sc, struct mfi_command *cmd)
 	if (!req_desc)
 		return NULL;
 
-	bzero(req_desc, sizeof(req_desc));
+	bzero(req_desc, sizeof(*req_desc));
 	req_desc->header.RequestFlags = (MPI2_REQ_DESCRIPT_FLAGS_SCSI_IO <<
 	    MFI_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);
 	req_desc->header.SMID = index;
diff --git a/sys/dev/mps/mps_sas.c b/sys/dev/mps/mps_sas.c
index 65009bc7fc8f..01af9fb007cf 100644
--- a/sys/dev/mps/mps_sas.c
+++ b/sys/dev/mps/mps_sas.c
@@ -2214,7 +2214,7 @@ mpssas_scsiio_complete(struct mps_softc *sc, struct mps_command *cm)
 			sense_len = min(returned_sense_len,
 			    ccb->csio.sense_len - ccb->csio.sense_resid);
 			bzero(&ccb->csio.sense_data,
-			      sizeof(&ccb->csio.sense_data));
+			      sizeof(ccb->csio.sense_data));
 			bcopy(cm->cm_sense, &ccb->csio.sense_data, sense_len);
 			ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
 		}
diff --git a/sys/dev/mpt/mpt_cam.c b/sys/dev/mpt/mpt_cam.c
index d312b6742b67..39619c2f3936 100644
--- a/sys/dev/mpt/mpt_cam.c
+++ b/sys/dev/mpt/mpt_cam.c
@@ -3187,7 +3187,7 @@ mpt_scsi_reply_frame_handler(struct mpt_softc *mpt, request_t *req,
 		else
 			ccb->csio.sense_resid = 0;
 
-		bzero(&ccb->csio.sense_data, sizeof(&ccb->csio.sense_data));
+		bzero(&ccb->csio.sense_data, sizeof(ccb->csio.sense_data));
 		bcopy(req->sense_vbuf, &ccb->csio.sense_data,
 		    min(ccb->csio.sense_len, sense_returned));
 	}
diff --git a/sys/kern/subr_firmware.c b/sys/kern/subr_firmware.c
index 2081987c6ff1..20ab76e282be 100644
--- a/sys/kern/subr_firmware.c
+++ b/sys/kern/subr_firmware.c
@@ -198,7 +198,7 @@ firmware_register(const char *imagename, const void *data, size_t datasize,
 		free(str, M_TEMP);
 		return NULL;
 	}
-	bzero(frp, sizeof(frp));	/* start from a clean record */
+	bzero(frp, sizeof(*frp));	/* start from a clean record */
 	frp->fw.name = str;
 	frp->fw.data = data;
 	frp->fw.datasize = datasize;
diff --git a/tools/tools/net80211/w00t/redir/buddy.c b/tools/tools/net80211/w00t/redir/buddy.c
index 7d66e042d753..02107eca23ac 100644
--- a/tools/tools/net80211/w00t/redir/buddy.c
+++ b/tools/tools/net80211/w00t/redir/buddy.c
@@ -125,7 +125,7 @@ int main(int argc, char *argv[])
 	int len;
 	int raw;
 
-	memset(&s_in, 0, sizeof(&s_in));
+	memset(&s_in, 0, sizeof(s_in));
 	s_in.sin_family = PF_INET;
 	s_in.sin_port = htons(666);
 	s_in.sin_addr.s_addr = INADDR_ANY;
diff --git a/tools/tools/net80211/wesside/dics/dics.c b/tools/tools/net80211/wesside/dics/dics.c
index 54bc981ebef3..cbdff0c0fcf3 100644
--- a/tools/tools/net80211/wesside/dics/dics.c
+++ b/tools/tools/net80211/wesside/dics/dics.c
@@ -332,7 +332,7 @@ int main(int argc, char *argv[]) {
 
 	sip = argv[1];
 
-	memset(&s_in, 0, sizeof(&s_in));
+	memset(&s_in, 0, sizeof(s_in));
 	us = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 	if (s == -1) {
 		perror("socket()");