From: Justin Tee justin.tee@broadcom.com
commit 97f975823f8196d970bd795087b514271214677a upstream.
Smatch detected a double free path because lpfc_nlp_not_used() releases an ndlp object before reaching lpfc_nlp_put() at the end of lpfc_cmpl_els_logo_acc().
Remove the outdated lpfc_nlp_not_used() routine. In lpfc_mbx_cmpl_ns_reg_login(), replace the call with lpfc_nlp_put(). In lpfc_cmpl_els_logo_acc(), replace the call with lpfc_unreg_rpi() and keep the lpfc_nlp_put() at the end of the routine. If ndlp's rpi was registered, then lpfc_unreg_rpi()'s completion routine performs the final ndlp clean up after lpfc_nlp_put() is called from lpfc_cmpl_els_logo_acc(). Otherwise if ndlp has no rpi registered, the lpfc_nlp_put() at the end of lpfc_cmpl_els_logo_acc() is the final ndlp clean up.
Fixes: 4430f7fd09ec ("scsi: lpfc: Rework locations of ndlp reference taking") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Dan Carpenter error27@gmail.com Link: https://lore.kernel.org/all/Y3OefhyyJNKH%2Fiaf@kili/ Signed-off-by: Justin Tee justin.tee@broadcom.com Link: https://lore.kernel.org/r/20230417191558.83100-3-justintee8345@gmail.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/lpfc/lpfc_crtn.h | 1 - drivers/scsi/lpfc/lpfc_els.c | 30 +++++++----------------------- drivers/scsi/lpfc/lpfc_hbadisc.c | 24 +++--------------------- 3 files changed, 10 insertions(+), 45 deletions(-)
--- a/drivers/scsi/lpfc/lpfc_crtn.h +++ b/drivers/scsi/lpfc/lpfc_crtn.h @@ -134,7 +134,6 @@ void lpfc_check_nlp_post_devloss(struct struct lpfc_nodelist *ndlp); void lpfc_ignore_els_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb, struct lpfc_iocbq *rspiocb); -int lpfc_nlp_not_used(struct lpfc_nodelist *ndlp); struct lpfc_nodelist *lpfc_setup_disc_node(struct lpfc_vport *, uint32_t); void lpfc_disc_list_loopmap(struct lpfc_vport *); void lpfc_disc_start(struct lpfc_vport *); --- a/drivers/scsi/lpfc/lpfc_els.c +++ b/drivers/scsi/lpfc/lpfc_els.c @@ -5150,14 +5150,9 @@ lpfc_els_free_iocb(struct lpfc_hba *phba * * This routine is the completion callback function to the Logout (LOGO) * Accept (ACC) Response ELS command. This routine is invoked to indicate - * the completion of the LOGO process. It invokes the lpfc_nlp_not_used() to - * release the ndlp if it has the last reference remaining (reference count - * is 1). If succeeded (meaning ndlp released), it sets the iocb ndlp - * field to NULL to inform the following lpfc_els_free_iocb() routine no - * ndlp reference count needs to be decremented. Otherwise, the ndlp - * reference use-count shall be decremented by the lpfc_els_free_iocb() - * routine. Finally, the lpfc_els_free_iocb() is invoked to release the - * IOCB data structure. + * the completion of the LOGO process. If the node has transitioned to NPR, + * this routine unregisters the RPI if it is still registered. The + * lpfc_els_free_iocb() is invoked to release the IOCB data structure. **/ static void lpfc_cmpl_els_logo_acc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb, @@ -5198,19 +5193,9 @@ lpfc_cmpl_els_logo_acc(struct lpfc_hba * (ndlp->nlp_last_elscmd == ELS_CMD_PLOGI)) goto out;
- /* NPort Recovery mode or node is just allocated */ - if (!lpfc_nlp_not_used(ndlp)) { - /* A LOGO is completing and the node is in NPR state. - * Just unregister the RPI because the node is still - * required. - */ + if (ndlp->nlp_flag & NLP_RPI_REGISTERED) lpfc_unreg_rpi(vport, ndlp); - } else { - /* Indicate the node has already released, should - * not reference to it from within lpfc_els_free_iocb. - */ - cmdiocb->ndlp = NULL; - } + } out: /* @@ -5230,9 +5215,8 @@ lpfc_cmpl_els_logo_acc(struct lpfc_hba * * RPI (Remote Port Index) mailbox command to the @phba. It simply releases * the associated lpfc Direct Memory Access (DMA) buffer back to the pool and * decrements the ndlp reference count held for this completion callback - * function. After that, it invokes the lpfc_nlp_not_used() to check - * whether there is only one reference left on the ndlp. If so, it will - * perform one more decrement and trigger the release of the ndlp. + * function. After that, it invokes the lpfc_drop_node to check + * whether it is appropriate to release the node. **/ void lpfc_mbx_cmpl_dflt_rpi(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb) --- a/drivers/scsi/lpfc/lpfc_hbadisc.c +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c @@ -4332,13 +4332,14 @@ out:
/* If the node is not registered with the scsi or nvme * transport, remove the fabric node. The failed reg_login - * is terminal. + * is terminal and forces the removal of the last node + * reference. */ if (!(ndlp->fc4_xpt_flags & (SCSI_XPT_REGD | NVME_XPT_REGD))) { spin_lock_irq(&ndlp->lock); ndlp->nlp_flag &= ~NLP_NPR_2B_DISC; spin_unlock_irq(&ndlp->lock); - lpfc_nlp_not_used(ndlp); + lpfc_nlp_put(ndlp); }
if (phba->fc_topology == LPFC_TOPOLOGY_LOOP) { @@ -6703,25 +6704,6 @@ lpfc_nlp_put(struct lpfc_nodelist *ndlp) return ndlp ? kref_put(&ndlp->kref, lpfc_nlp_release) : 0; }
-/* This routine free's the specified nodelist if it is not in use - * by any other discovery thread. This routine returns 1 if the - * ndlp has been freed. A return value of 0 indicates the ndlp is - * not yet been released. - */ -int -lpfc_nlp_not_used(struct lpfc_nodelist *ndlp) -{ - lpfc_debugfs_disc_trc(ndlp->vport, LPFC_DISC_TRC_NODE, - "node not used: did:x%x flg:x%x refcnt:x%x", - ndlp->nlp_DID, ndlp->nlp_flag, - kref_read(&ndlp->kref)); - - if (kref_read(&ndlp->kref) == 1) - if (lpfc_nlp_put(ndlp)) - return 1; - return 0; -} - /** * lpfc_fcf_inuse - Check if FCF can be unregistered. * @phba: Pointer to hba context object.