Updated: 2025-01-10 21:55:02.120829
Description:
In the Linux kernel, the following vulnerability has been resolved: 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: ---truncated---
Links | NIST | CIRCL | RHEL | Ubuntu |
Severity | Score | |
---|---|---|
CVSS Version 2.x | 0 | |
CVSS Version 3.x | MEDIUM | 4.7 |
OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
---|---|---|---|---|---|---|---|---|
AlmaLinux 9.2 ESU | kernel | 5.14.0 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:51 | ||
AlmaLinux 9.2 FIPS | kernel | 5.14.0 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:51 | ||
CentOS 6 ELS | kernel | 2.6.32 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:52 | ||
CentOS 7 ELS | kernel | 3.10.0 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:51 | ||
CentOS 8.4 ELS | kernel | 4.18.0 | 4.7 | MEDIUM | Released | CLSA-2024:1727690947 | 2024-09-30 10:46:48 | |
CentOS 8.5 ELS | kernel | 4.18.0 | 4.7 | MEDIUM | Released | CLSA-2024:1727690025 | 2024-09-30 10:46:49 | |
CentOS Stream 8 ELS | kernel | 4.18.0 | 4.7 | MEDIUM | Released | CLSA-2024:1727815919 | 2024-10-01 17:27:22 | |
CloudLinux 6 ELS | kernel | 2.6.32 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:51 | ||
CloudLinux 7 ELS | kernel | 3.10.0 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:51 | ||
Oracle Linux 6 ELS | kernel | 2.6.32 | 4.7 | MEDIUM | Ignored | 2024-09-25 12:26:51 |