4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit c41f59884be5cca293ed61f3d64637dbba3a6381 ]
We cannot wait on a completion object in the lpfc_nvme_targetport structure in the _destroy_targetport() code path because the NVMe/fc transport will free that structure immediately after the .targetport_delete() callback. This results in a use-after-free, and a hang if slub_debug=FZPU is enabled.
Fix this by putting the completion on the stack.
Signed-off-by: Ewan D. Milne emilne@redhat.com Acked-by: James Smart james.smart@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/lpfc/lpfc_nvmet.c | 8 +++++--- drivers/scsi/lpfc/lpfc_nvmet.h | 2 +- 2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c index b766afe10d3d7..e2575c8ec93e8 100644 --- a/drivers/scsi/lpfc/lpfc_nvmet.c +++ b/drivers/scsi/lpfc/lpfc_nvmet.c @@ -1003,7 +1003,8 @@ lpfc_nvmet_targetport_delete(struct nvmet_fc_target_port *targetport) struct lpfc_nvmet_tgtport *tport = targetport->private;
/* release any threads waiting for the unreg to complete */ - complete(&tport->tport_unreg_done); + if (tport->phba->targetport) + complete(tport->tport_unreg_cmp); }
static void @@ -1700,6 +1701,7 @@ lpfc_nvmet_destroy_targetport(struct lpfc_hba *phba) struct lpfc_nvmet_tgtport *tgtp; struct lpfc_queue *wq; uint32_t qidx; + DECLARE_COMPLETION_ONSTACK(tport_unreg_cmp);
if (phba->nvmet_support == 0) return; @@ -1709,9 +1711,9 @@ lpfc_nvmet_destroy_targetport(struct lpfc_hba *phba) wq = phba->sli4_hba.nvme_wq[qidx]; lpfc_nvmet_wqfull_flush(phba, wq, NULL); } - init_completion(&tgtp->tport_unreg_done); + tgtp->tport_unreg_cmp = &tport_unreg_cmp; nvmet_fc_unregister_targetport(phba->targetport); - wait_for_completion_timeout(&tgtp->tport_unreg_done, 5); + wait_for_completion_timeout(&tport_unreg_cmp, 5); lpfc_nvmet_cleanup_io_context(phba); } phba->targetport = NULL; diff --git a/drivers/scsi/lpfc/lpfc_nvmet.h b/drivers/scsi/lpfc/lpfc_nvmet.h index 1aaff63f1f419..0ec1082ce7ef6 100644 --- a/drivers/scsi/lpfc/lpfc_nvmet.h +++ b/drivers/scsi/lpfc/lpfc_nvmet.h @@ -34,7 +34,7 @@ /* Used for NVME Target */ struct lpfc_nvmet_tgtport { struct lpfc_hba *phba; - struct completion tport_unreg_done; + struct completion *tport_unreg_cmp;
/* Stats counters - lpfc_nvmet_unsol_ls_buffer */ atomic_t rcv_ls_req_in;