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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Naresh Kumar Inna <naresh@chelsio.com>
Cc: linux-scsi@vger.kernel.org, kbuild@01.org
Subject: re: [SCSI] csiostor: Chelsio FCoE offload driver
Date: Wed, 6 Feb 2013 16:09:43 +0300	[thread overview]
Message-ID: <20130206130943.GU4989@mwanda> (raw)

Hopefully, you recieved an email about this last November, but this
is a follow up because the bug is still there.

Smatch complains about a buffer overflow in this:

drivers/scsi/csiostor/csio_rnode.c:872 csio_rnode_fwevt_handler()
	error: buffer overflow '(rn)->stats.n_evt_fw' 22 <= 26

   859  void
   860  csio_rnode_fwevt_handler(struct csio_rnode *rn, uint8_t fwevt)
   861  {
   862          struct csio_lnode *ln = csio_rnode_to_lnode(rn);
   863          enum csio_rn_ev evt;
   864  
   865          evt = CSIO_FWE_TO_RNFE(fwevt);
   866          if (!evt) {

Events greater than PROTO_ERR_IMPL_LOGO are invalid.

   867                  csio_ln_err(ln, "ssni:x%x Unhandled FW Rdev event: %d\n",
   868                              csio_rn_flowid(rn), fwevt);
   869                  CSIO_INC_STATS(rn, n_evt_unexp);
   870                  return;
   871          }
   872          CSIO_INC_STATS(rn, n_evt_fw[fwevt]);

It looks like new events were added and the size of the n_evt_fw[]
array wasn't updated to hold them.  Everything after RSCN_DEV_LOST
causes memory corruption.

   RSCN_DEV_LOST           = 0x16,
   SCR_ACC_RCVD            = 0x17,
   ADISC_RJT_RCVD          = 0x18,
   LOGO_SNT                = 0x19,
   PROTO_ERR_IMPL_LOGO     = 0x1a,

There is a related bug in the lnode version of this code which
Smatch does not catch.

drivers/scsi/csiostor/csio_lnode.c
  1555                          /* save previous event for debugging */
  1556                          ln->prev_evt = ln->cur_evt;
  1557                          ln->cur_evt = rdev_wr->event_cause;
  1558                          CSIO_INC_STATS(ln, n_evt_fw[rdev_wr->event_cause]);
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Memory corruption.

  1559  
  1560                          /* Translate all the fabric events to lnode SM events */
  1561                          evt = CSIO_FWE_TO_LNE(rdev_wr->event_cause);
  1562                          if (evt) {

Valid events handled here but we already corrupted memory three
lines earlier.

  1563                                  csio_ln_dbg(ln,
  1564                                          "Posting event to lnode event:%d "
  1565                                          "cause:%d flowid:x%x\n", evt,
  1566                                          rdev_wr->event_cause, rdev_flowid);
  1567                                  csio_post_event(&ln->sm, evt);
  1568                          }
  1569  

I wasn't a part of the discussion in November, but the fix for this
seems trivial.  I'm probably missing something?

regards,
dan carpenter

             reply	other threads:[~2013-02-06 13:09 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-06 13:09 Dan Carpenter [this message]
2013-02-08  7:34 ` [SCSI] csiostor: Chelsio FCoE offload driver Naresh Kumar Inna
  -- strict thread matches above, loose matches on Subject: below --
2014-04-16 15:33 Dan Carpenter
2014-04-16 15:37 ` Dan Carpenter
2015-02-26  9:49   ` Dan Carpenter

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