4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mauricio Faria de Oliveira <mauricfo@xxxxxxxxxxxxxxxxxx>
commit 2319f847a8910cff1d46c9b66aa1dd7cc3e836a9 upstream.
The BUG_ON() recently introduced in lpfc_sli_ringtxcmpl_put() is hit in
the lpfc_els_abort() > lpfc_sli_issue_abort_iotag() >
lpfc_sli_abort_iotag_issue() function path [similar names], due to
'piocb->vport == NULL':
BUG_ON(!piocb || !piocb->vport);
This happens because lpfc_sli_abort_iotag_issue() doesn't set the
'abtsiocbp->vport' pointer -- but this is not the problem.
Previously, lpfc_sli_ringtxcmpl_put() accessed 'piocb->vport' only if
'piocb->iocb.ulpCommand' is neither CMD_ABORT_XRI_CN nor
CMD_CLOSE_XRI_CN, which are the only possible values for
lpfc_sli_abort_iotag_issue():
lpfc_sli_ringtxcmpl_put():
if ((unlikely(pring->ringno == LPFC_ELS_RING)) &&
(piocb->iocb.ulpCommand != CMD_ABORT_XRI_CN) &&
(piocb->iocb.ulpCommand != CMD_CLOSE_XRI_CN) &&
(!(piocb->vport->load_flag & FC_UNLOADING)))
lpfc_sli_abort_iotag_issue():
if (phba->link_state >= LPFC_LINK_UP)
iabt->ulpCommand = CMD_ABORT_XRI_CN;
else
iabt->ulpCommand = CMD_CLOSE_XRI_CN;
So, this function path would not have hit this possible NULL pointer
dereference before.
In order to fix this regression, move the second part of the BUG_ON()
check prior to the pointer dereference that it does check for.
For reference, this is the stack trace observed. The problem happened
because an unsolicited event was received - a PLOGI was received after
our PLOGI was issued but not yet complete, so the discovery state
machine goes on to sw-abort our PLOGI.
kernel BUG at drivers/scsi/lpfc/lpfc_sli.c:1326!
Oops: Exception in kernel mode, sig: 5 [#1]
<...>
NIP [...] lpfc_sli_ringtxcmpl_put+0x1c/0xf0 [lpfc]
LR [...] __lpfc_sli_issue_iocb_s4+0x188/0x200 [lpfc]
Call Trace:
[...] [...] __lpfc_sli_issue_iocb_s4+0xb0/0x200 [lpfc] (unreliable)
[...] [...] lpfc_sli_issue_abort_iotag+0x2b4/0x350 [lpfc]
[...] [...] lpfc_els_abort+0x1a8/0x4a0 [lpfc]
[...] [...] lpfc_rcv_plogi+0x6d4/0x700 [lpfc]
[...] [...] lpfc_rcv_plogi_plogi_issue+0xd8/0x1d0 [lpfc]
[...] [...] lpfc_disc_state_machine+0xc0/0x2b0 [lpfc]
[...] [...] lpfc_els_unsol_buffer+0xcc0/0x26c0 [lpfc]
[...] [...] lpfc_els_unsol_event+0xa8/0x220 [lpfc]
[...] [...] lpfc_complete_unsol_iocb+0xb8/0x138 [lpfc]
[...] [...] lpfc_sli4_handle_received_buffer+0x6a0/0xec0 [lpfc]
[...] [...] lpfc_sli_handle_slow_ring_event_s4+0x1c4/0x240 [lpfc]
[...] [...] lpfc_sli_handle_slow_ring_event+0x24/0x40 [lpfc]
[...] [...] lpfc_do_work+0xd88/0x1970 [lpfc]
[...] [...] kthread+0x108/0x130
[...] [...] ret_from_kernel_thread+0x5c/0xbc
<...>
Fixes: 22466da5b4b7 ("lpfc: Fix possible NULL pointer dereference")
Reported-by: Harsha Thyagaraja <hathyaga@xxxxxxxxxx>
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/lpfc/lpfc_sli.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -1323,18 +1323,20 @@ lpfc_sli_ringtxcmpl_put(struct lpfc_hba
{
lockdep_assert_held(&phba->hbalock);
- BUG_ON(!piocb || !piocb->vport);
+ BUG_ON(!piocb);
list_add_tail(&piocb->list, &pring->txcmplq);
piocb->iocb_flag |= LPFC_IO_ON_TXCMPLQ;
if ((unlikely(pring->ringno == LPFC_ELS_RING)) &&
(piocb->iocb.ulpCommand != CMD_ABORT_XRI_CN) &&
- (piocb->iocb.ulpCommand != CMD_CLOSE_XRI_CN) &&
- (!(piocb->vport->load_flag & FC_UNLOADING)))
- mod_timer(&piocb->vport->els_tmofunc,
- jiffies +
- msecs_to_jiffies(1000 * (phba->fc_ratov << 1)));
+ (piocb->iocb.ulpCommand != CMD_CLOSE_XRI_CN)) {
+ BUG_ON(!piocb->vport);
+ if (!(piocb->vport->load_flag & FC_UNLOADING))
+ mod_timer(&piocb->vport->els_tmofunc,
+ jiffies +
+ msecs_to_jiffies(1000 * (phba->fc_ratov << 1)));
+ }
return 0;
}
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