ghsa-f7hm-xqp4-h2q8
Vulnerability from github
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):
-
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:
-
Updating the name to the HIDPP name (harmless race):
if (hidpp->name == hdev->name) { ... hidpp->name = new_name; }
-
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);
}
-
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:
- This is all devm-maganaged
- The hidpp->battery.desc struct is shared between the 2 power supplies
- 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---
{
"affected": [],
"aliases": [
"CVE-2023-52478"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-29T06:15:45Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nHID: logitech-hidpp: Fix kernel crash on receiver USB disconnect\n\nhidpp_connect_event() has *four* time-of-check vs time-of-use (TOCTOU)\nraces when it races with itself.\n\nhidpp_connect_event() primarily runs from a workqueue but it also runs\non probe() and if a \"device-connected\" packet is received by the hw\nwhen the thread running hidpp_connect_event() from probe() is waiting on\nthe hw, then a second thread running hidpp_connect_event() will be\nstarted from the workqueue.\n\nThis opens the following races (note the below code is simplified):\n\n1. Retrieving + printing the protocol (harmless race):\n\n\tif (!hidpp-\u003eprotocol_major) {\n\t\thidpp_root_get_protocol_version()\n\t\thidpp-\u003eprotocol_major = response.rap.params[0];\n\t}\n\nWe can actually see this race hit in the dmesg in the abrt output\nattached to rhbz#2227968:\n\n[ 3064.624215] logitech-hidpp-device 0003:046D:4071.0049: HID++ 4.5 device connected.\n[ 3064.658184] logitech-hidpp-device 0003:046D:4071.0049: HID++ 4.5 device connected.\n\nTesting with extra logging added has shown that after this the 2 threads\ntake turn grabbing the hw access mutex (send_mutex) so they ping-pong\nthrough all the other TOCTOU cases managing to hit all of them:\n\n2. Updating the name to the HIDPP name (harmless race):\n\n\tif (hidpp-\u003ename == hdev-\u003ename) {\n\t\t...\n\t\thidpp-\u003ename = new_name;\n\t}\n\n3. Initializing the power_supply class for the battery (problematic!):\n\nhidpp_initialize_battery()\n{\n if (hidpp-\u003ebattery.ps)\n return 0;\n\n\tprobe_battery(); /* Blocks, threads take turns executing this */\n\n\thidpp-\u003ebattery.desc.properties =\n\t\tdevm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);\n\n\thidpp-\u003ebattery.ps =\n\t\tdevm_power_supply_register(\u0026hidpp-\u003ehid_dev-\u003edev,\n\t\t\t\t\t \u0026hidpp-\u003ebattery.desc, cfg);\n}\n\n4. Creating delayed input_device (potentially problematic):\n\n\tif (hidpp-\u003edelayed_input)\n\t\treturn;\n\n\thidpp-\u003edelayed_input = hidpp_allocate_input(hdev);\n\nThe really big problem here is 3. Hitting the race leads to the following\nsequence:\n\n\thidpp-\u003ebattery.desc.properties =\n\t\tdevm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);\n\n\thidpp-\u003ebattery.ps =\n\t\tdevm_power_supply_register(\u0026hidpp-\u003ehid_dev-\u003edev,\n\t\t\t\t\t \u0026hidpp-\u003ebattery.desc, cfg);\n\n\t...\n\n\thidpp-\u003ebattery.desc.properties =\n\t\tdevm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);\n\n\thidpp-\u003ebattery.ps =\n\t\tdevm_power_supply_register(\u0026hidpp-\u003ehid_dev-\u003edev,\n\t\t\t\t\t \u0026hidpp-\u003ebattery.desc, cfg);\n\nSo now we have registered 2 power supplies for the same battery,\nwhich looks a bit weird from userspace\u0027s pov but this is not even\nthe really big problem.\n\nNotice how:\n\n1. This is all devm-maganaged\n2. The hidpp-\u003ebattery.desc struct is shared between the 2 power supplies\n3. hidpp-\u003ebattery.desc.properties points to the result from the second\n devm_kmemdup()\n\nThis causes a use after free scenario on USB disconnect of the receiver:\n1. The last registered power supply class device gets unregistered\n2. The memory from the last devm_kmemdup() call gets freed,\n hidpp-\u003ebattery.desc.properties now points to freed memory\n3. The first registered power supply class device gets unregistered,\n this involves sending a remove uevent to userspace which invokes\n power_supply_uevent() to fill the uevent data\n4. power_supply_uevent() uses hidpp-\u003ebattery.desc.properties which\n now points to freed memory leading to backtraces like this one:\n\nSep 22 20:01:35 eric kernel: BUG: unable to handle page fault for address: ffffb2140e017f08\n...\nSep 22 20:01:35 eric kernel: Workqueue: usb_hub_wq hub_event\nSep 22 20:01:35 eric kernel: RIP: 0010:power_supply_uevent+0xee/0x1d0\n...\nSep 22 20:01:35 eric kernel: ? asm_exc_page_fault+0x26/0x30\nSep 22 20:01:35 eric kernel: ? power_supply_uevent+0xee/0x1d0\nSep 22 20:01:35 eric kernel: ? power_supply_uevent+0x10d/0x1d0\nSep 22 20:01:35 eric kernel: dev_uevent+0x10f/0x2d0\nSep 22 20:01:35 eric kernel: kobject_uevent_env+0x291/0x680\nSep 22 20:01:35 eric kernel: \n---truncated---",
"id": "GHSA-f7hm-xqp4-h2q8",
"modified": "2024-02-29T06:30:32Z",
"published": "2024-02-29T06:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-52478"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/093af62c023537f097d2ebdfaa0bc7c1a6e874e1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/28ddc1e0b898291323b62d770b1b931de131a528"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/44481b244fcaa2b895a53081d6204c574720c38c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ca0c4cc1d215dc22ab0e738c9f017c650f3183f5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cd0e2bf7fb22fe9b989c59c42dca06367fd10e6b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dac501397b9d81e4782232c39f94f4307b137452"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f7b2c7d9831af99369fe8ad9b2a68d78942f414e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fd72ac9556a473fc7daf54efb6ca8a97180d621d"
}
],
"schema_version": "1.4.0",
"severity": []
}