{"id":"DEBIAN-CVE-2023-52478","details":"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):  \tif (!hidpp-\u003eprotocol_major) { \t\thidpp_root_get_protocol_version() \t\thidpp-\u003eprotocol_major = response.rap.params[0]; \t}  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):  \tif (hidpp-\u003ename == hdev-\u003ename) { \t\t... \t\thidpp-\u003ename = new_name; \t}  3. Initializing the power_supply class for the battery (problematic!):  hidpp_initialize_battery() {         if (hidpp-\u003ebattery.ps)                 return 0;  \tprobe_battery(); /* Blocks, threads take turns executing this */  \thidpp-\u003ebattery.desc.properties = \t\tdevm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);  \thidpp-\u003ebattery.ps = \t\tdevm_power_supply_register(&hidpp-\u003ehid_dev-\u003edev, \t\t\t\t\t   &hidpp-\u003ebattery.desc, cfg); }  4. Creating delayed input_device (potentially problematic):  \tif (hidpp-\u003edelayed_input) \t\treturn;  \thidpp-\u003edelayed_input = hidpp_allocate_input(hdev);  The really big problem here is 3. Hitting the race leads to the following sequence:  \thidpp-\u003ebattery.desc.properties = \t\tdevm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);  \thidpp-\u003ebattery.ps = \t\tdevm_power_supply_register(&hidpp-\u003ehid_dev-\u003edev, \t\t\t\t\t   &hidpp-\u003ebattery.desc, cfg);  \t...  \thidpp-\u003ebattery.desc.properties = \t\tdevm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);  \thidpp-\u003ebattery.ps = \t\tdevm_power_supply_register(&hidpp-\u003ehid_dev-\u003edev, \t\t\t\t\t   &hidpp-\u003ebattery.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-\u003ebattery.desc struct is shared between the 2 power supplies 3. hidpp-\u003ebattery.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-\u003ebattery.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-\u003ebattery.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---","modified":"2026-09-15T09:02:47.702312545Z","published":"2024-02-29T06:15:45.920Z","upstream":["CVE-2023-52478"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-52478"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.64-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52478.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.8-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52478.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.8-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52478.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}