On 08/31/2015 10:48 PM, James Smart wrote: > > From: Johannes Thumshirn <jthumshirn@xxxxxxx> > > If the bf_get() call in lpfc_mbx_cmpl_rdp_page_a2() does succeeds, execution > continues normally and mp gets kfree()d. > > If the subsequent call to lpfc_sli_issue_mbox() fails execution jumps to the > error label where lpfc_mbuf_free() is called with mp->virt and mp->phys as > function arguments. This is the use after free. Following the use after free mp > gets kfree()d again which is a double free. > > Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx> > Signed-off-by: James Smart <james.smart@xxxxxxxxxxxxx> > --- > drivers/scsi/lpfc/lpfc_mbox.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/lpfc/lpfc_mbox.c b/drivers/scsi/lpfc/lpfc_mbox.c > index 723e110..18838ea 100644 > --- a/drivers/scsi/lpfc/lpfc_mbox.c > +++ b/drivers/scsi/lpfc/lpfc_mbox.c > @@ -2276,7 +2276,7 @@ lpfc_mbx_cmpl_rdp_page_a2(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox) > (struct lpfc_rdp_context *)(mbox->context2); > > if (bf_get(lpfc_mqe_status, &mbox->u.mqe)) > - goto error; > + goto error_mbuf_free; > > lpfc_sli_bemem_bcopy(mp->virt, &rdp_context->page_a2, > DMP_SFF_PAGE_A2_SIZE); > @@ -2291,13 +2291,14 @@ lpfc_mbx_cmpl_rdp_page_a2(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox) > mbox->mbox_cmpl = lpfc_mbx_cmpl_rdp_link_stat; > mbox->context2 = (struct lpfc_rdp_context *) rdp_context; > if (lpfc_sli_issue_mbox(phba, mbox, MBX_NOWAIT) == MBX_NOT_FINISHED) > - goto error; > + goto error_cmd_free; > > return; > > -error: > +error_mbuf_free: > lpfc_mbuf_free(phba, mp->virt, mp->phys); > kfree(mp); > +error_cmd_free: > lpfc_sli4_mbox_cmd_free(phba, mbox); > rdp_context->cmpl(phba, rdp_context, FAILURE); > } > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
