lpfc: Fix illegal memory access on Abort IOCBs

Commit Message

James Smart April 21, 2021, 11:41 p.m. UTC

In devloss timer handler and in backend calls to terminate remote port
io, there is logic to walk through all active IOCBs and validate them
to potentially trigger an abort request. This logic is causing illegal
memory accesses which leads to a crash. Abort IOCBs, which may be on
the list, do not have an associated lpfc_io_buf struct. The driver is
trying to map an lpfc_io_buf struct on the iocb and which results in a
bogus address thus the issue.

Fix by skipping over ABORT IOCBs (CLOSE IOCBs are ABORTS that don't send
ABTS) in the IOCB scan logic.

Co-developed-by: Justin Tee <[e-mail]>
Signed-off-by: Justin Tee <[e-mail]>
Signed-off-by: James Smart <[e-mail]>

ECD submit header:

        ****************************************

        COMMIT-TITLE: Logic to validate IOCB for aborts causes illegal memory access
        COMMIT: 78307
        COMMIT-BZ: 244869
        COMMIT-QC:

r78307 | sb889165 | 2021-03-12 09:00:53 +0530 (Fri, 12 Mar 2021) | 32 lines

Logic to validate IOCB for aborts causes illegal memory access

Bugs: 244869

Reviewers: jsmart pely jinfante

Symptoms:
In devloss timer handler and in backend calls to terminate remote port io,
there is logic to walk through all active IOCBs and validate them to
potentially trigger abort request. This logic causes illegal memory access
which leads to a crash.

Cause:
Abort IOCBs are not associated with lpfc_io_buf structure. While validating
FCP IOCBs, the function tries to map abort IOCB request to lpfc_io_buf struct
using container_of macros. This causes illegal memory access and thus leads
to interpreting junk values eventually leading to crash.

Fix:
Skip over abort IOCBs and IOCBs that have already been aborted.

Notes:

Unit Testing:

System Testing:
- Tested with ocs_fc_ramd SCSI target driver
- Trigger lips on initiator node
- Trigger port swaps and run io in background

Review_ID: https://cmengapps1.lvn.broadcom.net/r/34278/
---
 drivers/scsi/lpfc/lpfc_sli.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Patch

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 06ccc0157bd8..579ac75dfe79 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -11804,13 +11804,20 @@  lpfc_sli_validate_fcp_iocb(struct lpfc_iocbq *iocbq, struct lpfc_vport *vport,
 			   lpfc_ctx_cmd ctx_cmd)
 {
 	struct lpfc_io_buf *lpfc_cmd;
+	IOCB_t *icmd = NULL;
 	int rc = 1;
 
 	if (!iocbq || iocbq->vport != vport)
 		return rc;
 
-	if (!(iocbq->iocb_flag &  LPFC_IO_FCP) ||
-	    !(iocbq->iocb_flag & LPFC_IO_ON_TXCMPLQ))
+	if (!(iocbq->iocb_flag & LPFC_IO_FCP) ||
+	    !(iocbq->iocb_flag & LPFC_IO_ON_TXCMPLQ) ||
+	      iocbq->iocb_flag & LPFC_DRIVER_ABORTED)
+		return rc;
+
+	icmd = &iocbq->iocb;
+	if (icmd->ulpCommand == CMD_ABORT_XRI_CN ||
+	    icmd->ulpCommand == CMD_CLOSE_XRI_CN)
 		return rc;
 
 	lpfc_cmd = container_of(iocbq, struct lpfc_io_buf, cur_iocbq);