[PATCH 0/2] scsi: lpfc: bound EDC descriptor TLV walk

[Michael Bommarito <michael.bommarito@gmail.com>]

An adjacent Fibre Channel fabric peer or device can crash an LPFC host
with a malformed EDC ELS frame. lpfc_els_rcv_edc() trusts the EDC
descriptor-list length from the received frame without checking that it
fits in the actual ELS payload, so a short frame with an oversized
descriptor-list length walks the TLV list past the receive buffer and
trips a KASAN slab-out-of-bounds read in the ELS receive path.

Patch 1 passes the received payload length into lpfc_els_rcv_edc(),
rejects truncated EDC headers and descriptor lists larger than the
payload, and avoids logging a third payload word unless it is present.
Patch 2 adds same-translation-unit KUnit/KASAN coverage: a benign EDC
frame that must still parse and the malformed frame that must now be
rejected.

Reproduced with the KUnit/KASAN test on f5459048c38a: stock trips
BUG: KASAN: slab-out-of-bounds in lpfc_els_rcv_edc after the benign
control passes; patched rejects the frame and both cases pass.

Cc: stable@vger.kernel.org

Michael Bommarito (2):
  scsi: lpfc: bound EDC descriptor list by payload length
  scsi: lpfc: add KUnit coverage for EDC descriptor bounds

 drivers/scsi/Kconfig         |   7 ++
 drivers/scsi/lpfc/lpfc_els.c | 195 ++++++++++++++++++++++++++++++++---
 2 files changed, 189 insertions(+), 13 deletions(-)

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2.53.0