From 3d0107a7fee40402f0a3a325604bcbbc47597b5a Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 21 Jun 2021 12:07:10 -0700 Subject: scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Instead of writing beyond the end of evt_struct->iu.srp.cmd, target the upper union (evt_struct->iu.srp) instead, as that's what is being wiped. Cc: Tyrel Datwyler Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Kees Cook Acked-by: Martin K. Petersen Link: https://lore.kernel.org/lkml/yq135rzp79c.fsf@ca-mkp.ca.oracle.com Acked-by: Tyrel Datwyler Link: https://lore.kernel.org/lkml/6eae8434-e9a7-aa74-628b-b515b3695359@linux.ibm.com --- drivers/scsi/ibmvscsi/ibmvscsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/scsi') diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c index 50df7dd9cb91..ea8e01f49cba 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.c +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c @@ -1055,8 +1055,9 @@ static int ibmvscsi_queuecommand_lck(struct scsi_cmnd *cmnd, return SCSI_MLQUEUE_HOST_BUSY; /* Set up the actual SRP IU */ + BUILD_BUG_ON(sizeof(evt_struct->iu.srp) != SRP_MAX_IU_LEN); + memset(&evt_struct->iu.srp, 0x00, sizeof(evt_struct->iu.srp)); srp_cmd = &evt_struct->iu.srp.cmd; - memset(srp_cmd, 0x00, SRP_MAX_IU_LEN); srp_cmd->opcode = SRP_CMD; memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(srp_cmd->cdb)); int_to_scsilun(lun, &srp_cmd->lun); -- cgit v1.2.3