4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 7961cba6f7d8215fa632df3d220e5154bb825249 ]
We cannot wait on a completion object in the lpfc_nvme_lport structure in the _destroy_localport() code path because the NVMe/fc transport will free that structure immediately after the .localport_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_nvme.c | 16 +++++++++------- drivers/scsi/lpfc/lpfc_nvme.h | 2 +- 2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c index ba831def9301d..b6fe88de372a8 100644 --- a/drivers/scsi/lpfc/lpfc_nvme.c +++ b/drivers/scsi/lpfc/lpfc_nvme.c @@ -297,7 +297,8 @@ lpfc_nvme_localport_delete(struct nvme_fc_local_port *localport) lport);
/* release any threads waiting for the unreg to complete */ - complete(&lport->lport_unreg_done); + if (lport->vport->localport) + complete(lport->lport_unreg_cmp); }
/* lpfc_nvme_remoteport_delete @@ -2547,7 +2548,8 @@ lpfc_nvme_create_localport(struct lpfc_vport *vport) */ void lpfc_nvme_lport_unreg_wait(struct lpfc_vport *vport, - struct lpfc_nvme_lport *lport) + struct lpfc_nvme_lport *lport, + struct completion *lport_unreg_cmp) { #if (IS_ENABLED(CONFIG_NVME_FC)) u32 wait_tmo; @@ -2559,8 +2561,7 @@ lpfc_nvme_lport_unreg_wait(struct lpfc_vport *vport, */ wait_tmo = msecs_to_jiffies(LPFC_NVME_WAIT_TMO * 1000); while (true) { - ret = wait_for_completion_timeout(&lport->lport_unreg_done, - wait_tmo); + ret = wait_for_completion_timeout(lport_unreg_cmp, wait_tmo); if (unlikely(!ret)) { lpfc_printf_vlog(vport, KERN_ERR, LOG_NVME_IOERR, "6176 Lport %p Localport %p wait " @@ -2594,12 +2595,12 @@ lpfc_nvme_destroy_localport(struct lpfc_vport *vport) struct lpfc_nvme_lport *lport; struct lpfc_nvme_ctrl_stat *cstat; int ret; + DECLARE_COMPLETION_ONSTACK(lport_unreg_cmp);
if (vport->nvmei_support == 0) return;
localport = vport->localport; - vport->localport = NULL; lport = (struct lpfc_nvme_lport *)localport->private; cstat = lport->cstat;
@@ -2610,13 +2611,14 @@ lpfc_nvme_destroy_localport(struct lpfc_vport *vport) /* lport's rport list is clear. Unregister * lport and release resources. */ - init_completion(&lport->lport_unreg_done); + lport->lport_unreg_cmp = &lport_unreg_cmp; ret = nvme_fc_unregister_localport(localport);
/* Wait for completion. This either blocks * indefinitely or succeeds */ - lpfc_nvme_lport_unreg_wait(vport, lport); + lpfc_nvme_lport_unreg_wait(vport, lport, &lport_unreg_cmp); + vport->localport = NULL; kfree(cstat);
/* Regardless of the unregister upcall response, clear diff --git a/drivers/scsi/lpfc/lpfc_nvme.h b/drivers/scsi/lpfc/lpfc_nvme.h index cfd4719be25c3..b234d02989942 100644 --- a/drivers/scsi/lpfc/lpfc_nvme.h +++ b/drivers/scsi/lpfc/lpfc_nvme.h @@ -50,7 +50,7 @@ struct lpfc_nvme_ctrl_stat { /* Declare nvme-based local and remote port definitions. */ struct lpfc_nvme_lport { struct lpfc_vport *vport; - struct completion lport_unreg_done; + struct completion *lport_unreg_cmp; /* Add stats counters here */ struct lpfc_nvme_ctrl_stat *cstat; atomic_t fc4NvmeLsRequests;