[PATCH 6.6.y] scsi: lpfc: Handle mailbox timeouts in lpfc_get_sfp_info

[Artem Dinaburg <artem@trailofbits.com>]

From: Justin Tee <justin.tee@broadcom.com>

[ Upstream commit ede596b1434b57c0b3fd5c02b326efe5c54f6e48 ]

The MBX_TIMEOUT return code is not handled in lpfc_get_sfp_info and the
routine unconditionally frees submitted mailbox commands regardless of
return status.  The issue is that for MBX_TIMEOUT cases, when firmware
returns SFP information at a later time, that same mailbox memory region
references previously freed memory in its cmpl routine.

Fix by adding checks for the MBX_TIMEOUT return code.  During mailbox
resource cleanup, check the mbox flag to make sure that the wait did not
timeout.  If the MBOX_WAKE flag is not set, then do not free the resources
because it will be freed when firmware completes the mailbox at a later
time in its cmpl routine.

Also, increase the timeout from 30 to 60 seconds to accommodate boot
scripts requiring longer timeouts.

[ Backport to 6.6.y: v6.6 predates ext_buf and uses ctx_buf for the SLI3
  raw payload. Restore ctx_buf to the saved struct lpfc_dmabuf before
  testing LPFC_MBX_WAKE so a timed-out mailbox's late default completion
  sees the DMA descriptor rather than payload bytes. ]

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20240628172011.25921-6-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Assisted-by: LLM
Signed-off-by: Artem Dinaburg <artem@trailofbits.com>
---
Hi Greg, Sasha, and scsi lpfc maintainers,

I am working through the small CVE backports still missing from 6.6.y.
This one addresses CVE-2024-46842. It leaves timed-out mailbox storage
alive for the eventual firmware completion.

The fix is already present in 6.12.y, 6.18.y, and 7.2.y, but not in 6.6.y.
The target-specific adjustment is recorded in the bracketed note above.
Unlike mainline, 6.6.y temporarily stores the SLI3 mailbox payload in
ctx_buf. Restoring the saved DMA descriptor before returning after a timeout
keeps the eventual firmware completion on the expected cleanup path.

Could you please queue it for 6.6.y?

CVE: CVE-2024-46842
Upstream: ede596b1434b57c0b3fd5c02b326efe5c54f6e48

AI assistance: An LLM helped identify, adapt, and validate this backport; I
reviewed the resulting code and validation evidence.

Thanks,
Artem Dinaburg

 drivers/scsi/lpfc/lpfc_els.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 2e9972a5878103..d319df7d36137c 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -7310,12 +7310,13 @@ int lpfc_get_sfp_info_wait(struct lpfc_hba *phba,
 	mbox->vport = phba->pport;
 	mbox->ctx_ndlp = (struct lpfc_rdp_context *)rdp_context;
 
-	rc = lpfc_sli_issue_mbox_wait(phba, mbox, 30);
+	rc = lpfc_sli_issue_mbox_wait(phba, mbox, LPFC_MBOX_SLI4_CONFIG_TMO);
 	if (rc == MBX_NOT_FINISHED) {
 		rc = 1;
 		goto error;
 	}
-
+	if (rc == MBX_TIMEOUT)
+		goto error;
 	if (phba->sli_rev == LPFC_SLI_REV4)
 		mp = (struct lpfc_dmabuf *)(mbox->ctx_buf);
 	else
@@ -7367,9 +7368,11 @@ int lpfc_get_sfp_info_wait(struct lpfc_hba *phba,
 		mbox->u.mqe.un.mem_dump_type3.addr_lo = putPaddrLow(mp->phys);
 		mbox->u.mqe.un.mem_dump_type3.addr_hi = putPaddrHigh(mp->phys);
 	}
-
 	mbox->ctx_ndlp = (struct lpfc_rdp_context *)rdp_context;
-	rc = lpfc_sli_issue_mbox_wait(phba, mbox, 30);
+	rc = lpfc_sli_issue_mbox_wait(phba, mbox, LPFC_MBOX_SLI4_CONFIG_TMO);
+
+	if (rc == MBX_TIMEOUT)
+		goto error;
 	if (bf_get(lpfc_mqe_status, &mbox->u.mqe)) {
 		rc = 1;
 		goto error;
@@ -7380,8 +7383,9 @@ int lpfc_get_sfp_info_wait(struct lpfc_hba *phba,
 			     DMP_SFF_PAGE_A2_SIZE);
 
 error:
 	mbox->ctx_buf = mpsave;
-	lpfc_mbox_rsrc_cleanup(phba, mbox, MBOX_THD_UNLOCKED);
+	if (mbox->mbox_flag & LPFC_MBX_WAKE)
+		lpfc_mbox_rsrc_cleanup(phba, mbox, MBOX_THD_UNLOCKED);
 
 	return rc;
 
-- 
2.39.5