From 9af867c05b5d9f54f190743a1c761d70038c83b3 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 2 Oct 2023 17:58:57 +0200 Subject: HID: i2c-hid: fix handling of unpopulated devices A recent commit reordered probe so that the interrupt line is now requested before making sure that the device exists. This breaks machines like the Lenovo ThinkPad X13s which rely on the HID driver to probe second-source devices and only register the variant that is actually populated. Specifically, the interrupt line may now already be (temporarily) claimed when doing asynchronous probing of the touchpad: genirq: Flags mismatch irq 191. 00082008 (hid-over-i2c) vs. 00082008 (hid-over-i2c) i2c_hid_of 21-0015: Could not register for hid-over-i2c interrupt, irq = 191, ret = -16 i2c_hid_of: probe of 21-0015 failed with error -16 Fix this by restoring the old behaviour of first making sure the device exists before requesting the interrupt line. Note that something like this should probably be implemented also for "panel followers", whose actual probe is currently effectively deferred until the DRM panel is probed (e.g. by powering down the device after making sure it exists and only then register it as a follower). Fixes: 675cd877c952 ("HID: i2c-hid: Rearrange probe() to power things up later") Cc: Douglas Anderson Cc: Maxime Ripard Signed-off-by: Johan Hovold Tested-by: Dennis Gilmore Reviewed-by: Douglas Anderson Tested-by: Douglas Anderson Link: https://lore.kernel.org/r/20231002155857.24584-1-johan+linaro@kernel.org Signed-off-by: Benjamin Tissoires --- drivers/hid/i2c-hid/i2c-hid-core.c | 144 +++++++++++++++++++++---------------- 1 file changed, 81 insertions(+), 63 deletions(-) diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index 9601c0605fd9..2735cd585af0 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -998,45 +998,29 @@ static int i2c_hid_core_resume(struct i2c_hid *ihid) return hid_driver_reset_resume(hid); } -/** - * __do_i2c_hid_core_initial_power_up() - First time power up of the i2c-hid device. - * @ihid: The ihid object created during probe. - * - * This function is called at probe time. - * - * The initial power on is where we do some basic validation that the device - * exists, where we fetch the HID descriptor, and where we create the actual - * HID devices. - * - * Return: 0 or error code. +/* + * Check that the device exists and parse the HID descriptor. */ -static int __do_i2c_hid_core_initial_power_up(struct i2c_hid *ihid) +static int __i2c_hid_core_probe(struct i2c_hid *ihid) { struct i2c_client *client = ihid->client; struct hid_device *hid = ihid->hid; int ret; - ret = i2c_hid_core_power_up(ihid); - if (ret) - return ret; - /* Make sure there is something at this address */ ret = i2c_smbus_read_byte(client); if (ret < 0) { i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret); - ret = -ENXIO; - goto err; + return -ENXIO; } ret = i2c_hid_fetch_hid_descriptor(ihid); if (ret < 0) { dev_err(&client->dev, "Failed to fetch the HID Descriptor\n"); - goto err; + return ret; } - enable_irq(client->irq); - hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); hid->product = le16_to_cpu(ihid->hdesc.wProductID); @@ -1050,17 +1034,49 @@ static int __do_i2c_hid_core_initial_power_up(struct i2c_hid *ihid) ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); + return 0; +} + +static int i2c_hid_core_register_hid(struct i2c_hid *ihid) +{ + struct i2c_client *client = ihid->client; + struct hid_device *hid = ihid->hid; + int ret; + + enable_irq(client->irq); + ret = hid_add_device(hid); if (ret) { if (ret != -ENODEV) hid_err(client, "can't add hid device: %d\n", ret); - goto err; + disable_irq(client->irq); + return ret; } return 0; +} + +static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid) +{ + int ret; + + ret = i2c_hid_core_power_up(ihid); + if (ret) + return ret; -err: + ret = __i2c_hid_core_probe(ihid); + if (ret) + goto err_power_down; + + ret = i2c_hid_core_register_hid(ihid); + if (ret) + goto err_power_down; + + return 0; + +err_power_down: i2c_hid_core_power_down(ihid); + return ret; } @@ -1077,7 +1093,7 @@ static void ihid_core_panel_prepare_work(struct work_struct *work) * steps. */ if (!hid->version) - ret = __do_i2c_hid_core_initial_power_up(ihid); + ret = i2c_hid_core_probe_panel_follower(ihid); else ret = i2c_hid_core_resume(ihid); @@ -1136,7 +1152,6 @@ static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid) struct device *dev = &ihid->client->dev; int ret; - ihid->is_panel_follower = true; ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs; /* @@ -1156,30 +1171,6 @@ static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid) return 0; } -static int i2c_hid_core_initial_power_up(struct i2c_hid *ihid) -{ - /* - * If we're a panel follower, we'll register and do our initial power - * up when the panel turns on; otherwise we do it right away. - */ - if (drm_is_panel_follower(&ihid->client->dev)) - return i2c_hid_core_register_panel_follower(ihid); - else - return __do_i2c_hid_core_initial_power_up(ihid); -} - -static void i2c_hid_core_final_power_down(struct i2c_hid *ihid) -{ - /* - * If we're a follower, the act of unfollowing will cause us to be - * powered down. Otherwise we need to manually do it. - */ - if (ihid->is_panel_follower) - drm_panel_remove_follower(&ihid->panel_follower); - else - i2c_hid_core_suspend(ihid, true); -} - int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, u16 hid_descriptor_address, u32 quirks) { @@ -1211,6 +1202,7 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, ihid->ops = ops; ihid->client = client; ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address); + ihid->is_panel_follower = drm_is_panel_follower(&client->dev); init_waitqueue_head(&ihid->wait); mutex_init(&ihid->reset_lock); @@ -1224,14 +1216,10 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, return ret; device_enable_async_suspend(&client->dev); - ret = i2c_hid_init_irq(client); - if (ret < 0) - goto err_buffers_allocated; - hid = hid_allocate_device(); if (IS_ERR(hid)) { ret = PTR_ERR(hid); - goto err_irq; + goto err_free_buffers; } ihid->hid = hid; @@ -1242,19 +1230,42 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, hid->bus = BUS_I2C; hid->initial_quirks = quirks; - ret = i2c_hid_core_initial_power_up(ihid); + /* Power on and probe unless device is a panel follower. */ + if (!ihid->is_panel_follower) { + ret = i2c_hid_core_power_up(ihid); + if (ret < 0) + goto err_destroy_device; + + ret = __i2c_hid_core_probe(ihid); + if (ret < 0) + goto err_power_down; + } + + ret = i2c_hid_init_irq(client); + if (ret < 0) + goto err_power_down; + + /* + * If we're a panel follower, we'll register when the panel turns on; + * otherwise we do it right away. + */ + if (ihid->is_panel_follower) + ret = i2c_hid_core_register_panel_follower(ihid); + else + ret = i2c_hid_core_register_hid(ihid); if (ret) - goto err_mem_free; + goto err_free_irq; return 0; -err_mem_free: - hid_destroy_device(hid); - -err_irq: +err_free_irq: free_irq(client->irq, ihid); - -err_buffers_allocated: +err_power_down: + if (!ihid->is_panel_follower) + i2c_hid_core_power_down(ihid); +err_destroy_device: + hid_destroy_device(hid); +err_free_buffers: i2c_hid_free_buffers(ihid); return ret; @@ -1266,7 +1277,14 @@ void i2c_hid_core_remove(struct i2c_client *client) struct i2c_hid *ihid = i2c_get_clientdata(client); struct hid_device *hid; - i2c_hid_core_final_power_down(ihid); + /* + * If we're a follower, the act of unfollowing will cause us to be + * powered down. Otherwise we need to manually do it. + */ + if (ihid->is_panel_follower) + drm_panel_remove_follower(&ihid->panel_follower); + else + i2c_hid_core_suspend(ihid, true); hid = ihid->hid; hid_destroy_device(hid); -- cgit v1.2.3 From dac501397b9d81e4782232c39f94f4307b137452 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Thu, 5 Oct 2023 20:26:38 +0200 Subject: HID: logitech-hidpp: Fix kernel crash on receiver USB disconnect hidpp_connect_event() has *four* time-of-check vs time-of-use (TOCTOU) races when it races with itself. hidpp_connect_event() primarily runs from a workqueue but it also runs on probe() and if a "device-connected" packet is received by the hw when the thread running hidpp_connect_event() from probe() is waiting on the hw, then a second thread running hidpp_connect_event() will be started from the workqueue. This opens the following races (note the below code is simplified): 1. Retrieving + printing the protocol (harmless race): if (!hidpp->protocol_major) { hidpp_root_get_protocol_version() hidpp->protocol_major = response.rap.params[0]; } We can actually see this race hit in the dmesg in the abrt output attached to rhbz#2227968: [ 3064.624215] logitech-hidpp-device 0003:046D:4071.0049: HID++ 4.5 device connected. [ 3064.658184] logitech-hidpp-device 0003:046D:4071.0049: HID++ 4.5 device connected. Testing with extra logging added has shown that after this the 2 threads take turn grabbing the hw access mutex (send_mutex) so they ping-pong through all the other TOCTOU cases managing to hit all of them: 2. Updating the name to the HIDPP name (harmless race): if (hidpp->name == hdev->name) { ... hidpp->name = new_name; } 3. Initializing the power_supply class for the battery (problematic!): hidpp_initialize_battery() { if (hidpp->battery.ps) return 0; probe_battery(); /* Blocks, threads take turns executing this */ hidpp->battery.desc.properties = devm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL); hidpp->battery.ps = devm_power_supply_register(&hidpp->hid_dev->dev, &hidpp->battery.desc, cfg); } 4. Creating delayed input_device (potentially problematic): if (hidpp->delayed_input) return; hidpp->delayed_input = hidpp_allocate_input(hdev); The really big problem here is 3. Hitting the race leads to the following sequence: hidpp->battery.desc.properties = devm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL); hidpp->battery.ps = devm_power_supply_register(&hidpp->hid_dev->dev, &hidpp->battery.desc, cfg); ... hidpp->battery.desc.properties = devm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL); hidpp->battery.ps = devm_power_supply_register(&hidpp->hid_dev->dev, &hidpp->battery.desc, cfg); So now we have registered 2 power supplies for the same battery, which looks a bit weird from userspace's pov but this is not even the really big problem. Notice how: 1. This is all devm-maganaged 2. The hidpp->battery.desc struct is shared between the 2 power supplies 3. hidpp->battery.desc.properties points to the result from the second devm_kmemdup() This causes a use after free scenario on USB disconnect of the receiver: 1. The last registered power supply class device gets unregistered 2. The memory from the last devm_kmemdup() call gets freed, hidpp->battery.desc.properties now points to freed memory 3. The first registered power supply class device gets unregistered, this involves sending a remove uevent to userspace which invokes power_supply_uevent() to fill the uevent data 4. power_supply_uevent() uses hidpp->battery.desc.properties which now points to freed memory leading to backtraces like this one: Sep 22 20:01:35 eric kernel: BUG: unable to handle page fault for address: ffffb2140e017f08 ... Sep 22 20:01:35 eric kernel: Workqueue: usb_hub_wq hub_event Sep 22 20:01:35 eric kernel: RIP: 0010:power_supply_uevent+0xee/0x1d0 ... Sep 22 20:01:35 eric kernel: ? asm_exc_page_fault+0x26/0x30 Sep 22 20:01:35 eric kernel: ? power_supply_uevent+0xee/0x1d0 Sep 22 20:01:35 eric kernel: ? power_supply_uevent+0x10d/0x1d0 Sep 22 20:01:35 eric kernel: dev_uevent+0x10f/0x2d0 Sep 22 20:01:35 eric kernel: kobject_uevent_env+0x291/0x680 Sep 22 20:01:35 eric kernel: power_supply_unregister+0x8e/0xa0 Sep 22 20:01:35 eric kernel: release_nodes+0x3d/0xb0 Sep 22 20:01:35 eric kernel: devres_release_group+0xfc/0x130 Sep 22 20:01:35 eric kernel: hid_device_remove+0x56/0xa0 Sep 22 20:01:35 eric kernel: device_release_driver_internal+0x19f/0x200 Sep 22 20:01:35 eric kernel: bus_remove_device+0xc6/0x130 Sep 22 20:01:35 eric kernel: device_del+0x15c/0x3f0 Sep 22 20:01:35 eric kernel: ? __queue_work+0x1df/0x440 Sep 22 20:01:35 eric kernel: hid_destroy_device+0x4b/0x60 Sep 22 20:01:35 eric kernel: logi_dj_remove+0x9a/0x100 [hid_logitech_dj 5c91534a0ead2b65e04dd799a0437e3b99b21bc4] Sep 22 20:01:35 eric kernel: hid_device_remove+0x44/0xa0 Sep 22 20:01:35 eric kernel: device_release_driver_internal+0x19f/0x200 Sep 22 20:01:35 eric kernel: bus_remove_device+0xc6/0x130 Sep 22 20:01:35 eric kernel: device_del+0x15c/0x3f0 Sep 22 20:01:35 eric kernel: ? __queue_work+0x1df/0x440 Sep 22 20:01:35 eric kernel: hid_destroy_device+0x4b/0x60 Sep 22 20:01:35 eric kernel: usbhid_disconnect+0x47/0x60 [usbhid 727dcc1c0b94e6b4418727a468398ac3bca492f3] Sep 22 20:01:35 eric kernel: usb_unbind_interface+0x90/0x270 Sep 22 20:01:35 eric kernel: device_release_driver_internal+0x19f/0x200 Sep 22 20:01:35 eric kernel: bus_remove_device+0xc6/0x130 Sep 22 20:01:35 eric kernel: device_del+0x15c/0x3f0 Sep 22 20:01:35 eric kernel: ? kobject_put+0xa0/0x1d0 Sep 22 20:01:35 eric kernel: usb_disable_device+0xcd/0x1e0 Sep 22 20:01:35 eric kernel: usb_disconnect+0xde/0x2c0 Sep 22 20:01:35 eric kernel: usb_disconnect+0xc3/0x2c0 Sep 22 20:01:35 eric kernel: hub_event+0xe80/0x1c10 There have been quite a few bug reports (see Link tags) about this crash. Fix all the TOCTOU issues, including the really bad power-supply related system crash on USB disconnect, by making probe() use the workqueue for running hidpp_connect_event() too, so that it can never run more then once. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2227221 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2227968 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2227968 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2242189 Link: https://bugzilla.kernel.org/show_bug.cgi?id=217412#c58 Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20231005182638.3776-1-hdegoede@redhat.com Signed-off-by: Benjamin Tissoires --- drivers/hid/hid-logitech-hidpp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index ff077df0babf..a209d51bd247 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -4515,7 +4515,8 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) goto hid_hw_init_fail; } - hidpp_connect_event(hidpp); + schedule_work(&hidpp->work); + flush_work(&hidpp->work); if (will_restart) { /* Reset the HID node state */ -- cgit v1.2.3