From: Pan Bian <bianpan2016@xxxxxxx> [ Upstream commit ec990306f77fd4c58c3b27cc3b3c53032d6e6670 ] The memory chunk io_req is released by mempool_free. Accessing io_req->start_time will result in a use after free bug. The variable start_time is a backup of the timestamp. So, use start_time here to avoid use after free. Link: https://lore.kernel.org/r/1572881182-37664-1-git-send-email-bianpan2016@xxxxxxx Signed-off-by: Pan Bian <bianpan2016@xxxxxxx> Reviewed-by: Satish Kharat <satishkh@xxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 d79ac0b24f5af..04c25ca2be45f 100644 --- a/drivers/scsi/fnic/fnic_scsi.c +++ b/drivers/scsi/fnic/fnic_scsi.c @@ -1034,7 +1034,8 @@ 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); -- 2.25.1