lpfc: fix axchg pointer reference after free and double frees
The axchg structure is a structure allocated early in the
lpfc_nvme_unsol_ls_handler() to represent the newly received exchange.
Upon error, the out_fail path in the routine unconditionally frees the
pointer, yet subsequently passes the pointer to the abort routine.
Additionally, the abort routine, lpfc_nvme_unsol_ls_issue_abort(), also
has a failure path that will attempt to delete the pointer on error.
Fix these errors by:
- Removing the unconditional free so that it stays valid if passed
to the abort routine.
- Revise the abort routine to not free the pointer. Instead, return
a success/failure status. Note: if success, the later completion of
the abort frees the structure.
- Back in the unsol_ls_handler() error path, if the abort routine was
skipped (thus no possible reference) or the abort routine returned
error, free the pointer.
Fixes: 3a8070c567aa ("lpfc: Refactor NVME LS receive handling")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 1aaf400..9e21c4f 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -2813,7 +2813,7 @@ lpfc_nvme_unsol_ls_handler(struct lpfc_hba *phba, struct lpfc_iocbq *piocb)
struct lpfc_async_xchg_ctx *axchg = NULL;
char *failwhy = NULL;
uint32_t oxid, sid, did, fctl, size;
- int ret;
+ int ret = 1;
d_buf = piocb->context2;
@@ -2897,14 +2897,16 @@ lpfc_nvme_unsol_ls_handler(struct lpfc_hba *phba, struct lpfc_iocbq *piocb)
(phba->nvmet_support) ? "T" : "I", ret);
out_fail:
- kfree(axchg);
/* recycle receive buffer */
lpfc_in_buf_free(phba, &nvmebuf->dbuf);
/* If start of new exchange, abort it */
- if (fctl & FC_FC_FIRST_SEQ && !(fctl & FC_FC_EX_CTX))
- lpfc_nvme_unsol_ls_issue_abort(phba, axchg, sid, oxid);
+ if (axchg && (fctl & FC_FC_FIRST_SEQ && !(fctl & FC_FC_EX_CTX)))
+ ret = lpfc_nvme_unsol_ls_issue_abort(phba, axchg, sid, oxid);
+
+ if (ret)
+ kfree(axchg);
}
/**