From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- net/wireless/ap.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 net/wireless/ap.c (limited to 'net/wireless/ap.c') diff --git a/net/wireless/ap.c b/net/wireless/ap.c new file mode 100644 index 000000000..9a9a87080 --- /dev/null +++ b/net/wireless/ap.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Parts of this file are + * Copyright (C) 2022-2023 Intel Corporation + */ +#include +#include +#include +#include "nl80211.h" +#include "core.h" +#include "rdev-ops.h" + + +static int ___cfg80211_stop_ap(struct cfg80211_registered_device *rdev, + struct net_device *dev, unsigned int link_id, + bool notify) +{ + struct wireless_dev *wdev = dev->ieee80211_ptr; + int err; + + lockdep_assert_wiphy(wdev->wiphy); + + if (!rdev->ops->stop_ap) + return -EOPNOTSUPP; + + if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP && + dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO) + return -EOPNOTSUPP; + + if (!wdev->links[link_id].ap.beacon_interval) + return -ENOENT; + + err = rdev_stop_ap(rdev, dev, link_id); + if (!err) { + wdev->conn_owner_nlportid = 0; + wdev->links[link_id].ap.beacon_interval = 0; + memset(&wdev->links[link_id].ap.chandef, 0, + sizeof(wdev->links[link_id].ap.chandef)); + wdev->u.ap.ssid_len = 0; + rdev_set_qos_map(rdev, dev, NULL); + if (notify) + nl80211_send_ap_stopped(wdev, link_id); + + /* Should we apply the grace period during beaconing interface + * shutdown also? + */ + cfg80211_sched_dfs_chan_update(rdev); + } + + schedule_work(&cfg80211_disconnect_work); + + return err; +} + +int cfg80211_stop_ap(struct cfg80211_registered_device *rdev, + struct net_device *dev, int link_id, + bool notify) +{ + unsigned int link; + int ret = 0; + + if (link_id >= 0) + return ___cfg80211_stop_ap(rdev, dev, link_id, notify); + + for_each_valid_link(dev->ieee80211_ptr, link) { + int ret1 = ___cfg80211_stop_ap(rdev, dev, link, notify); + + if (ret1) + ret = ret1; + /* try the next one also if one errored */ + } + + return ret; +} -- cgit v1.3.1