lkml.org 
[lkml]   [2020]   [Apr]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 5.4 10/78] scsi: lpfc: Fix crash in target side cable pulls hitting WAIT_FOR_UNREG
    Date
    From: James Smart <jsmart2021@gmail.com>

    [ Upstream commit 807e7353d8a7105ce884d22b0dbc034993c6679c ]

    Kernel is crashing with the following stacktrace:

    BUG: unable to handle kernel NULL pointer dereference at
    00000000000005bc
    IP: lpfc_nvme_register_port+0x1a8/0x3a0 [lpfc]
    ...
    Call Trace:
    lpfc_nlp_state_cleanup+0x2b2/0x500 [lpfc]
    lpfc_nlp_set_state+0xd7/0x1a0 [lpfc]
    lpfc_cmpl_prli_prli_issue+0x1f7/0x450 [lpfc]
    lpfc_disc_state_machine+0x7a/0x1e0 [lpfc]
    lpfc_cmpl_els_prli+0x16f/0x1e0 [lpfc]
    lpfc_sli_sp_handle_rspiocb+0x5b2/0x690 [lpfc]
    lpfc_sli_handle_slow_ring_event_s4+0x182/0x230 [lpfc]
    lpfc_do_work+0x87f/0x1570 [lpfc]
    kthread+0x10d/0x130
    ret_from_fork+0x35/0x40

    During target side fault injections, it is possible to hit the
    NLP_WAIT_FOR_UNREG case in lpfc_nvme_remoteport_delete. A prior commit
    fixed a rebind and delete race condition, but called lpfc_nlp_put
    unconditionally. This triggered a deletion and the crash.

    Fix by movng nlp_put to inside the NLP_WAIT_FOR_UNREG case, where the nlp
    will be being unregistered/removed. Leave the reference if the flag isn't
    set.

    Link: https://lore.kernel.org/r/20200322181304.37655-8-jsmart2021@gmail.com
    Fixes: b15bd3e6212e ("scsi: lpfc: Fix nvme remoteport registration race conditions")
    Signed-off-by: James Smart <jsmart2021@gmail.com>
    Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
    Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/scsi/lpfc/lpfc_nvme.c | 14 ++++++++------
    1 file changed, 8 insertions(+), 6 deletions(-)

    diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c
    index 8e0f03ef346b6..c475ae0f2f515 100644
    --- a/drivers/scsi/lpfc/lpfc_nvme.c
    +++ b/drivers/scsi/lpfc/lpfc_nvme.c
    @@ -342,13 +342,15 @@ lpfc_nvme_remoteport_delete(struct nvme_fc_remote_port *remoteport)
    if (ndlp->upcall_flags & NLP_WAIT_FOR_UNREG) {
    ndlp->nrport = NULL;
    ndlp->upcall_flags &= ~NLP_WAIT_FOR_UNREG;
    - }
    - spin_unlock_irq(&vport->phba->hbalock);
    + spin_unlock_irq(&vport->phba->hbalock);

    - /* Remove original register reference. The host transport
    - * won't reference this rport/remoteport any further.
    - */
    - lpfc_nlp_put(ndlp);
    + /* Remove original register reference. The host transport
    + * won't reference this rport/remoteport any further.
    + */
    + lpfc_nlp_put(ndlp);
    + } else {
    + spin_unlock_irq(&vport->phba->hbalock);
    + }

    rport_err:
    return;
    --
    2.20.1
    \
     
     \ /
      Last update: 2020-04-18 16:56    [W:4.245 / U:0.096 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site