| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.7 156/204] scsi: lpfc: nvmet: Avoid hang / use-after-free again when destroying targetport | Date | Thu, 20 Aug 2020 11:20:53 +0200 |
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From: Ewan D. Milne <emilne@redhat.com>
[ Upstream commit af6de8c60fe9433afa73cea6fcccdccd98ad3e5e ]
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 crash if slub_debug=FZPU is enabled.
An earlier fix put put the completion on the stack, but commit 2a0fb340fcc8 ("scsi: lpfc: Correct localport timeout duration error") subsequently changed the code to reference the completion through a pointer in the object rather than the local stack variable. Fix this by using the stack variable directly.
Link: https://lore.kernel.org/r/20200729231011.13240-1-emilne@redhat.com Fixes: 2a0fb340fcc8 ("scsi: lpfc: Correct localport timeout duration error") Reviewed-by: James Smart <james.smart@broadcom.com> Signed-off-by: Ewan D. Milne <emilne@redhat.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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c index 565419bf8d74a..40b2df6e304ad 100644 --- a/drivers/scsi/lpfc/lpfc_nvmet.c +++ b/drivers/scsi/lpfc/lpfc_nvmet.c @@ -1914,7 +1914,7 @@ lpfc_nvmet_destroy_targetport(struct lpfc_hba *phba) } tgtp->tport_unreg_cmp = &tport_unreg_cmp; nvmet_fc_unregister_targetport(phba->targetport); - if (!wait_for_completion_timeout(tgtp->tport_unreg_cmp, + if (!wait_for_completion_timeout(&tport_unreg_cmp, msecs_to_jiffies(LPFC_NVMET_WAIT_TMO))) lpfc_printf_log(phba, KERN_ERR, LOG_NVME, "6179 Unreg targetport x%px timeout " -- 2.25.1
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