svn commit: r291656 - stable/9/sys/netsmb

[Rick Macklem]

Author: rmacklem
Date: Wed Dec  2 21:56:01 2015
New Revision: 291656
URL: https://svnweb.freebsd.org/changeset/base/291656

Log:
  MFC: r291035
  The problem report was for a crash that happened when smbfs was
  trying to do a mount. Given the backtrace,
  it appears that the crash occurred when smb_vc_create() failed and then
  called smb_vc_put() with vcp->vc_iod == NULL. smb_vc_put() subsequently
  called smb_vc_disconnect() with vcp->vc_iod == NULL, causing the crash.
  This patch adds a check for vcp->vc_iod != NULL in smb_vc_disconnect() to
  avoid the crash. It also fixes the case in smb_vc_create() where
  kproc_create() fails so that it destroys the mutexes and sets
  vcp->vc_iod == NULL before free()'ing the iod structure.

Modified:
  stable/9/sys/netsmb/smb_conn.c
  stable/9/sys/netsmb/smb_iod.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/netsmb/smb_conn.c
==============================================================================
--- stable/9/sys/netsmb/smb_conn.c	Wed Dec  2 21:48:34 2015	(r291655)
+++ stable/9/sys/netsmb/smb_conn.c	Wed Dec  2 21:56:01 2015	(r291656)
@@ -654,7 +654,9 @@ int
 smb_vc_disconnect(struct smb_vc *vcp)
 {
 
-	smb_iod_request(vcp->vc_iod, SMBIOD_EV_DISCONNECT | SMBIOD_EV_SYNC, NULL);
+	if (vcp->vc_iod != NULL)
+		smb_iod_request(vcp->vc_iod, SMBIOD_EV_DISCONNECT |
+		    SMBIOD_EV_SYNC, NULL);
 	return 0;
 }
 

Modified: stable/9/sys/netsmb/smb_iod.c
==============================================================================
--- stable/9/sys/netsmb/smb_iod.c	Wed Dec  2 21:48:34 2015	(r291655)
+++ stable/9/sys/netsmb/smb_iod.c	Wed Dec  2 21:56:01 2015	(r291656)
@@ -690,6 +690,9 @@ smb_iod_create(struct smb_vc *vcp)
 	    RFNOWAIT, 0, "smbiod%d", iod->iod_id);
 	if (error) {
 		SMBERROR("can't start smbiod: %d", error);
+		vcp->vc_iod = NULL;
+		smb_sl_destroy(&iod->iod_rqlock);
+		smb_sl_destroy(&iod->iod_evlock);
 		free(iod, M_SMBIOD);
 		return error;
 	}