From 21681b81b9ae548c5dae7ae00d931197a27f480c Mon Sep 17 00:00:00 2001 From: Justin Tee Date: Mon, 9 Jan 2023 15:33:13 -0800 Subject: [PATCH] scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write During the sysfs firmware write process, a use-after-free read warning is logged from the lpfc_wr_object() routine: BUG: KFENCE: use-after-free read in lpfc_wr_object+0x235/0x310 [lpfc] Use-after-free read at 0x0000000000cf164d (in kfence-#111): lpfc_wr_object+0x235/0x310 [lpfc] lpfc_write_firmware.cold+0x206/0x30d [lpfc] lpfc_sli4_request_firmware_update+0xa6/0x100 [lpfc] lpfc_request_firmware_upgrade_store+0x66/0xb0 [lpfc] kernfs_fop_write_iter+0x121/0x1b0 new_sync_write+0x11c/0x1b0 vfs_write+0x1ef/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x59/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The driver accessed wr_object pointer data, which was initialized into mailbox payload memory, after the mailbox object was released back to the mailbox pool. Fix by moving the mailbox free calls to the end of the routine ensuring that we don't reference internal mailbox memory after release. Signed-off-by: Justin Tee Signed-off-by: Martin K. Petersen --- drivers/scsi/lpfc/lpfc_sli.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index c21187c93a5fd1..55dfab9ae3c970 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -20815,6 +20815,7 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list, struct lpfc_mbx_wr_object *wr_object; LPFC_MBOXQ_t *mbox; int rc = 0, i = 0; + int mbox_status = 0; uint32_t shdr_status, shdr_add_status, shdr_add_status_2; uint32_t shdr_change_status = 0, shdr_csf = 0; uint32_t mbox_tmo; @@ -20860,11 +20861,15 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list, wr_object->u.request.bde_count = i; bf_set(lpfc_wr_object_write_length, &wr_object->u.request, written); if (!phba->sli4_hba.intr_enable) - rc = lpfc_sli_issue_mbox(phba, mbox, MBX_POLL); + mbox_status = lpfc_sli_issue_mbox(phba, mbox, MBX_POLL); else { mbox_tmo = lpfc_mbox_tmo_val(phba, mbox); - rc = lpfc_sli_issue_mbox_wait(phba, mbox, mbox_tmo); + mbox_status = lpfc_sli_issue_mbox_wait(phba, mbox, mbox_tmo); } + + /* The mbox status needs to be maintained to detect MBOX_TIMEOUT. */ + rc = mbox_status; + /* The IOCTL status is embedded in the mailbox subheader. */ shdr_status = bf_get(lpfc_mbox_hdr_status, &wr_object->header.cfg_shdr.response); @@ -20879,10 +20884,6 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list, &wr_object->u.response); } - if (!phba->sli4_hba.intr_enable) - mempool_free(mbox, phba->mbox_mem_pool); - else if (rc != MBX_TIMEOUT) - mempool_free(mbox, phba->mbox_mem_pool); if (shdr_status || shdr_add_status || shdr_add_status_2 || rc) { lpfc_printf_log(phba, KERN_ERR, LOG_TRACE_EVENT, "3025 Write Object mailbox failed with " @@ -20900,6 +20901,12 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list, lpfc_log_fw_write_cmpl(phba, shdr_status, shdr_add_status, shdr_add_status_2, shdr_change_status, shdr_csf); + + if (!phba->sli4_hba.intr_enable) + mempool_free(mbox, phba->mbox_mem_pool); + else if (mbox_status != MBX_TIMEOUT) + mempool_free(mbox, phba->mbox_mem_pool); + return rc; }