forked from Minki/linux
2319f847a8
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
<...>
Cc: stable@vger.kernel.org # v4.8
Fixes:
|
||
|---|---|---|
| .. | ||
| lpfc_attr.c | ||
| lpfc_attr.h | ||
| lpfc_bsg.c | ||
| lpfc_bsg.h | ||
| lpfc_compat.h | ||
| lpfc_crtn.h | ||
| lpfc_ct.c | ||
| lpfc_debugfs.c | ||
| lpfc_debugfs.h | ||
| lpfc_disc.h | ||
| lpfc_els.c | ||
| lpfc_hbadisc.c | ||
| lpfc_hw4.h | ||
| lpfc_hw.h | ||
| lpfc_ids.h | ||
| lpfc_init.c | ||
| lpfc_logmsg.h | ||
| lpfc_mbox.c | ||
| lpfc_mem.c | ||
| lpfc_nl.h | ||
| lpfc_nportdisc.c | ||
| lpfc_scsi.c | ||
| lpfc_scsi.h | ||
| lpfc_sli4.h | ||
| lpfc_sli.c | ||
| lpfc_sli.h | ||
| lpfc_version.h | ||
| lpfc_vport.c | ||
| lpfc_vport.h | ||
| lpfc.h | ||
| Makefile | ||