From: Ying Hsu <yinghsu@chromium.org> mainline inclusion from mainline-v6.6-rc1 commit 573ebae162111063eedc6c838a659ba628f66a0f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID0RG9 CVE: CVE-2023-53520 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier may still be accessing it, it can cause the program to crash. Here's the call trace: <4>[102152.653246] Call Trace: <4>[102152.653254] hci_suspend_sync+0x109/0x301 [bluetooth] <4>[102152.653259] hci_suspend_dev+0x78/0xcd [bluetooth] <4>[102152.653263] hci_suspend_notifier+0x42/0x7a [bluetooth] <4>[102152.653268] notifier_call_chain+0x43/0x6b <4>[102152.653271] __blocking_notifier_call_chain+0x48/0x69 <4>[102152.653273] __pm_notifier_call_chain+0x22/0x39 <4>[102152.653276] pm_suspend+0x287/0x57c <4>[102152.653278] state_store+0xae/0xe5 <4>[102152.653281] kernfs_fop_write+0x109/0x173 <4>[102152.653284] __vfs_write+0x16f/0x1a2 <4>[102152.653287] ? selinux_file_permission+0xca/0x16f <4>[102152.653289] ? security_file_permission+0x36/0x109 <4>[102152.653291] vfs_write+0x114/0x21d <4>[102152.653293] __x64_sys_write+0x7b/0xdb <4>[102152.653296] do_syscall_64+0x59/0x194 <4>[102152.653299] entry_SYSCALL_64_after_hwframe+0x5c/0xc1 This patch holds the reference count of the hci_dev object while processing it in hci_suspend_notifier to avoid potential crash caused by the race condition. Signed-off-by: Ying Hsu <yinghsu@chromium.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Conflicts: net/bluetooth/hci_core.c [conflicts due to not merge e1b77d68feea ("Bluetooth: Make use of hci_{suspend,resume}_dev on suspend notifier")] Signed-off-by: Wang Liang <wangliang74@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 0a517bdf2de6..e3b98fd6e1f3 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3559,6 +3559,9 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action, goto done; } + /* To avoid a potential race with hci_unregister_dev. */ + hci_dev_hold(hdev); + /* Suspend notifier should only act on events when powered. */ if (!hdev_is_powered(hdev) || hci_dev_test_flag(hdev, HCI_UNREGISTER)) @@ -3602,6 +3605,7 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action, bt_dev_err(hdev, "Suspend notifier action (%lu) failed: %d", action, ret); + hci_dev_put(hdev); return NOTIFY_DONE; } -- 2.34.1