2.6.27-longterm review patch.  If anyone has any objections, please let us know.

------------------

commit 5911e963d3718e306bcac387b83e259aa4228896 upstream.

If expander discovery fails (sas_discover_expander()), remove the
expander from the port device list (sas_ex_discover_expander()),
before freeing it. Else the list is corrupted and, e.g., when we
attempt to send SMP commands to other devices, the kernel oopses.

Signed-off-by: Luben Tuikov <redacted>
Reviewed-by: Jack Wang <redacted>
Signed-off-by: James Bottomley <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/scsi/libsas/sas_expander.c |    3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

Index: longterm-2.6.27/drivers/scsi/libsas/sas_expander.c
===================================================================

--- longterm-2.6.27.orig/drivers/scsi/libsas/sas_expander.c    2012-02-05 22:34:34.059914940 +0100
+++ longterm-2.6.27/drivers/scsi/libsas/sas_expander.c    2012-02-05 22:34:39.404915902 +0100

@@ -839,6 +839,9 @@

   res = sas_discover_expander(child);
   if (res) {
+        spin_lock_irq(&parent->port->dev_list_lock);
+        list_del(&child->dev_list_node);
+        spin_unlock_irq(&parent->port->dev_list_lock);
       kfree(child);
       return NULL;
   }