[PATCH 1/1] scsi: iscsi: Fix iscsi_task use after free
From: Mike Christie <michael.christie@oracle.com>
Date: 2021-10-04 21:06:40
Subsystem:
iscsi, scsi subsystem, the rest · Maintainers:
Lee Duncan, Chris Leech, Mike Christie, "James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
The patch:
d39df158518c ("scsi: iscsi: Have abort handler get ref to conn")
added iscsi_get_conn/iscsi_put_conn calls during abort handling but then
also changed the handling of the case where we detect an already completed
task where we now end up doing a goto to the common put/cleanup code. This
results in a iscsi_task use after free, because the common cleanup code
will do a put on the iscsi_task.
This reverts the goto and moves the iscsi_get_conn to after we've checked
if the iscsi_task is valid.
Fixes: d39df158518c ("scsi: iscsi: Have abort handler get ref to conn")
Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
drivers/scsi/libiscsi.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 4683c183e9d4..5bc91d34df63 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c@@ -2281,11 +2281,6 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) return FAILED; } - conn = session->leadconn; - iscsi_get_conn(conn->cls_conn); - conn->eh_abort_cnt++; - age = session->age; - spin_lock(&session->back_lock); task = (struct iscsi_task *)sc->SCp.ptr; if (!task || !task->sc) {
@@ -2293,8 +2288,16 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) ISCSI_DBG_EH(session, "sc completed while abort in progress\n"); spin_unlock(&session->back_lock); - goto success; + spin_unlock_bh(&session->frwd_lock); + mutex_unlock(&session->eh_mutex); + return SUCCESS; } + + conn = session->leadconn; + iscsi_get_conn(conn->cls_conn); + conn->eh_abort_cnt++; + age = session->age; + ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt); __iscsi_get_task(task); spin_unlock(&session->back_lock);
--
2.25.1