[PATCH 5.15 041/121] scsi: mpt3sas: Fix use-after-free warning

Greg Kroah-Hartman
2022-09-13T14:38:16Z

From: Sreekanth Reddy <sreekanth.reddy@broadcom.com>

commit 991df3dd5144f2e6b1c38b8d20ed3d4d21e20b34 upstream.

Fix the following use-after-free warning which is observed during
controller reset:

refcount_t: underflow; use-after-free.
WARNING: CPU: 23 PID: 5399 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0

Link: https://lore.kernel.org/r/20220906134908.1039-2-sreekanth.reddy@broadcom.com
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -3670,6 +3670,7 @@ static struct fw_event_work *dequeue_nex
fw_event = list_first_entry(&ioc->fw_event_list,
struct fw_event_work, list);
list_del_init(&fw_event->list);
+ fw_event_work_put(fw_event);
}
spin_unlock_irqrestore(&ioc->fw_event_lock, flags);

@@ -3751,7 +3752,6 @@ _scsih_fw_event_cleanup_queue(struct MPT
if (cancel_work_sync(&fw_event->work))
fw_event_work_put(fw_event);

- fw_event_work_put(fw_event);
}
ioc->fw_events_cleanup = 0;
}