[PATCH 1/1] scsi: fnic: fix use after free

From: Pan Bian
Date: Mon Nov 04 2019 - 10:41:55 EST


The memory chunk io_req is released by mempool_free. Accessing
io_req->start_time will result in a use after free bug. Thevariable
start_time is a backup of the timestamp. So, use start_time here to
avoid use after free.

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
---
drivers/scsi/fnic/fnic_scsi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index 80608b53897b..d3986a25d9c2 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -1024,7 +1024,8 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic,
atomic64_inc(&fnic_stats->io_stats.io_completions);


- io_duration_time = jiffies_to_msecs(jiffies) - jiffies_to_msecs(io_req->start_time);
+ io_duration_time = jiffies_to_msecs(jiffies) -
+ jiffies_to_msecs(start_time);

if(io_duration_time <= 10)
atomic64_inc(&fnic_stats->io_stats.io_btw_0_to_10_msec);
--
2.7.4