From 6dc618cdd6b896791313926becb1f86ede0e046a Mon Sep 17 00:00:00 2001 From: Elena Reshetova Date: Thu, 9 Mar 2017 13:46:58 +0200 Subject: [PATCH] scsi: libiscsi: qedi: convert iscsi_task.refcount from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Acked-by: Chris Leech Signed-off-by: Martin K. Petersen --- drivers/scsi/libiscsi.c | 8 ++++---- drivers/scsi/qedi/qedi_iscsi.c | 2 +- include/scsi/libiscsi.h | 3 ++- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 07c08ce..ec38a18 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -517,13 +517,13 @@ static void iscsi_free_task(struct iscsi_task *task) void __iscsi_get_task(struct iscsi_task *task) { - atomic_inc(&task->refcount); + refcount_inc(&task->refcount); } EXPORT_SYMBOL_GPL(__iscsi_get_task); void __iscsi_put_task(struct iscsi_task *task) { - if (atomic_dec_and_test(&task->refcount)) + if (refcount_dec_and_test(&task->refcount)) iscsi_free_task(task); } EXPORT_SYMBOL_GPL(__iscsi_put_task); @@ -745,7 +745,7 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, * released by the lld when it has transmitted the task for * pdus we do not expect a response for. */ - atomic_set(&task->refcount, 1); + refcount_set(&task->refcount, 1); task->conn = conn; task->sc = NULL; INIT_LIST_HEAD(&task->running); @@ -1617,7 +1617,7 @@ static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn, sc->SCp.phase = conn->session->age; sc->SCp.ptr = (char *) task; - atomic_set(&task->refcount, 1); + refcount_set(&task->refcount, 1); task->state = ISCSI_TASK_PENDING; task->conn = conn; task->sc = sc; diff --git a/drivers/scsi/qedi/qedi_iscsi.c b/drivers/scsi/qedi/qedi_iscsi.c index b9f79d3..3895bd5 100644 --- a/drivers/scsi/qedi/qedi_iscsi.c +++ b/drivers/scsi/qedi/qedi_iscsi.c @@ -1372,7 +1372,7 @@ static void qedi_cleanup_task(struct iscsi_task *task) { if (!task->sc || task->state == ISCSI_TASK_PENDING) { QEDI_INFO(NULL, QEDI_LOG_IO, "Returning ref_cnt=%d\n", - atomic_read(&task->refcount)); + refcount_read(&task->refcount)); return; } diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h index b0e275d..24d74b5 100644 --- a/include/scsi/libiscsi.h +++ b/include/scsi/libiscsi.h @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -139,7 +140,7 @@ struct iscsi_task { /* state set/tested under session->lock */ int state; - atomic_t refcount; + refcount_t refcount; struct list_head running; /* running cmd list */ void *dd_data; /* driver/transport data */ }; -- 2.7.4