From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp

stable inclusion from stable-v6.6.42 commit d6cbce18370641a21dd889e8613d8153df15eb39 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEN8 CVE: CVE-2024-41063

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 0d151a103775dd9645c78c97f77d6e2a5298d913 ]

syzbot is reporting that calling hci_release_dev() from hci_error_reset() due to hci_dev_put() from hci_error_reset() can cause deadlock at destroy_workqueue(), for hci_error_reset() is called from hdev->req_workqueue which destroy_workqueue() needs to flush.

We need to make sure that hdev->{rx_work,cmd_work,tx_work} which are queued into hdev->workqueue and hdev->{power_on,error_reset} which are queued into hdev->req_workqueue are no longer running by the moment

destroy_workqueue(hdev->workqueue); destroy_workqueue(hdev->req_workqueue);

are called from hci_release_dev().

Call cancel_work_sync() on these work items from hci_unregister_dev() as soon as hdev->list is removed from hci_dev_list.

Reported-by: syzbot syzbot+da0a9c9721e36db712e8@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=da0a9c9721e36db712e8 Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com --- net/bluetooth/hci_core.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 3817d6369f0c..b4d5b7200ff9 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2704,7 +2704,11 @@ void hci_unregister_dev(struct hci_dev *hdev) list_del(&hdev->list); write_unlock(&hci_dev_list_lock);

+ cancel_work_sync(&hdev->rx_work); + cancel_work_sync(&hdev->cmd_work); + cancel_work_sync(&hdev->tx_work); cancel_work_sync(&hdev->power_on); + cancel_work_sync(&hdev->error_reset);

hci_cmd_sync_clear(hdev);