From: Zheng Wang Date: Thu, 16 Mar 2023 16:15:26 +0000 (+0800) Subject: xirc2ps_cs: Fix use after free bug in xirc2ps_detach X-Git-Tag: v6.3-rc4~28^2~32 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e8d20c3ded59a092532513c9bd030d1ea66f5f44;p=thirdparty%2Fkernel%2Flinux.git xirc2ps_cs: Fix use after free bug in xirc2ps_detach In xirc2ps_probe, the local->tx_timeout_task was bounded with xirc2ps_tx_timeout_task. When timeout occurs, it will call xirc_tx_timeout->schedule_work to start the work. When we call xirc2ps_detach to remove the driver, there may be a sequence as follows: Stop responding to timeout tasks and complete scheduled tasks before cleanup in xirc2ps_detach, which will fix the problem. CPU0 CPU1 |xirc2ps_tx_timeout_task xirc2ps_detach | free_netdev | kfree(dev); | | | do_reset | //use dev Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Zheng Wang Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/xircom/xirc2ps_cs.c b/drivers/net/ethernet/xircom/xirc2ps_cs.c index 894e92ef415b9..9f505cf02d965 100644 --- a/drivers/net/ethernet/xircom/xirc2ps_cs.c +++ b/drivers/net/ethernet/xircom/xirc2ps_cs.c @@ -503,6 +503,11 @@ static void xirc2ps_detach(struct pcmcia_device *link) { struct net_device *dev = link->priv; + struct local_info *local = netdev_priv(dev); + + netif_carrier_off(dev); + netif_tx_disable(dev); + cancel_work_sync(&local->tx_timeout_task); dev_dbg(&link->dev, "detach\n");