From 358d41fb476d6e428f3e36069a9e65527cebf9f7 Mon Sep 17 00:00:00 2001 From: John Evans Date: Thu, 28 Aug 2025 12:40:08 +0800 Subject: [PATCH] scsi: lpfc: Fix buffer free/clear order in deferred receive path ANBZ: #25280 commit baa39f6ad79d372a6ce0aa639fbb2f1578479f57 stable. commit 9dba9a45c348e8460da97c450cddf70b2056deb3 upstream. Fix a use-after-free window by correcting the buffer release sequence in the deferred receive path. The code freed the RQ buffer first and only then cleared the context pointer under the lock. Concurrent paths (e.g., ABTS and the repost path) also inspect and release the same pointer under the lock, so the old order could lead to double-free/UAF. Note that the repost path already uses the correct pattern: detach the pointer under the lock, then free it after dropping the lock. The deferred path should do the same. Fixes: 472e146d1cf3 ("scsi: lpfc: Correct upcalling nvmet_fc transport during io done downcall") Cc: stable@vger.kernel.org Signed-off-by: John Evans Link: https://lore.kernel.org/r/20250828044008.743-1-evans1210144@gmail.com Reviewed-by: Justin Tee Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman Fixes: CVE-2025-39841 Signed-off-by: Xiao Long Signed-off-by: Guixin Liu --- drivers/scsi/lpfc/lpfc_nvmet.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c index deab8931ab48..63f112694423 100644 --- a/drivers/scsi/lpfc/lpfc_nvmet.c +++ b/drivers/scsi/lpfc/lpfc_nvmet.c @@ -1245,7 +1245,7 @@ lpfc_nvmet_defer_rcv(struct nvmet_fc_target_port *tgtport, struct lpfc_nvmet_tgtport *tgtp; struct lpfc_async_xchg_ctx *ctxp = container_of(rsp, struct lpfc_async_xchg_ctx, hdlrctx.fcp_req); - struct rqb_dmabuf *nvmebuf = ctxp->rqb_buffer; + struct rqb_dmabuf *nvmebuf; struct lpfc_hba *phba = ctxp->phba; unsigned long iflag; @@ -1253,13 +1253,18 @@ lpfc_nvmet_defer_rcv(struct nvmet_fc_target_port *tgtport, lpfc_nvmeio_data(phba, "NVMET DEFERRCV: xri x%x sz %d CPU %02x\n", ctxp->oxid, ctxp->size, raw_smp_processor_id()); + spin_lock_irqsave(&ctxp->ctxlock, iflag); + nvmebuf = ctxp->rqb_buffer; if (!nvmebuf) { + spin_unlock_irqrestore(&ctxp->ctxlock, iflag); lpfc_printf_log(phba, KERN_INFO, LOG_NVME_IOERR, "6425 Defer rcv: no buffer oxid x%x: " "flg %x ste %x\n", ctxp->oxid, ctxp->flag, ctxp->state); return; } + ctxp->rqb_buffer = NULL; + spin_unlock_irqrestore(&ctxp->ctxlock, iflag); tgtp = phba->targetport->private; if (tgtp) @@ -1267,9 +1272,6 @@ lpfc_nvmet_defer_rcv(struct nvmet_fc_target_port *tgtport, /* Free the nvmebuf since a new buffer already replaced it */ nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf); - spin_lock_irqsave(&ctxp->ctxlock, iflag); - ctxp->rqb_buffer = NULL; - spin_unlock_irqrestore(&ctxp->ctxlock, iflag); } /** -- Gitee