cbcvebase.
CVE-2022-50220
published 2025-06-18

CVE-2022-50220: In the Linux kernel, the following vulnerability has been resolved: usbnet: Fix linkwatch use-after-free on disconnect usbnet uses the work…

PriorityP339high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.20%
10.4th percentile
In the Linux kernel, the following vulnerability has been resolved: usbnet: Fix linkwatch use-after-free on disconnect usbnet uses the work usbnet_deferred_kevent() to perform tasks which may sleep. On disconnect, completion of the work was originally awaited in ->ndo_stop(). But in 2003, that was moved to ->disconnect() by historic commit "[PATCH] USB: usbnet, prevent exotic rtnl deadlock": https://git.kernel.org/tglx/history/c/0f138bbfd83c The change was made because back then, the kernel's workqueue implementation did not allow waiting for a single work. One had to wait for completion of *all* work by calling flush_scheduled_work(), and that could deadlock when waiting for usbnet_deferred_kevent() with rtnl_mutex held in ->ndo_stop(). The commit solved one problem but created another: It causes a use-after-free in USB Ethernet drivers aqc111.c, asix_devices.c, ax88179_178a.c, ch9200.c and smsc75xx.c: * If the drivers receive a link change interrupt immediately before disconnect, they raise EVENT_LINK_RESET in their (non-sleepable) ->status() callback and schedule usbnet_deferred_kevent(). * usbnet_deferred_kevent() invokes the driver's ->link_reset() callback, which calls netif_carrier_{on,off}(). * That in turn schedules the work linkwatch_event(). Because usbnet_deferred_kevent() is awaited after unregister_netdev(), netif_carrier_{on,off}() may operate on an unregistered netdev and linkwatch_event() may run after free_netdev(), causing a use-after-free. In 2010, usbnet was changed to only wait for a single instance of usbnet_deferred_kevent() instead of *all* work by commit 23f333a2bfaf ("drivers/net: don't use flush_scheduled_work()"). Unfortunately the commit neglected to move the wait back to ->ndo_stop(). Rectify that omission at long last.

Affected

23 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.0.2-1 (bookworm)linux 6.0.2-1 (bookworm)
linuxlinux
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < d2d6b530d89b0a912148018027386aa049f0a309d2d6b530d89b0a912148018027386aa049f0a309
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < e2a521a7dcc463c5017b4426ca0804e151faeff7e2a521a7dcc463c5017b4426ca0804e151faeff7
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < 7f77dcbc030c2faa6d8e8a594985eeb34018409e7f77dcbc030c2faa6d8e8a594985eeb34018409e
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < 8b4588b8b00b299be16a35be67b331d8fdba03f38b4588b8b00b299be16a35be67b331d8fdba03f3
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < 135199a2edd459d2b123144efcd7f9bcd95128e4135199a2edd459d2b123144efcd7f9bcd95128e4
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < 635fd8953e4309b54ca6a81bed1d4a87668694f4635fd8953e4309b54ca6a81bed1d4a87668694f4
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < d49bb8cf9bfaa06aa527eb30f1a52a071da2e32fd49bb8cf9bfaa06aa527eb30f1a52a071da2e32f
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < db3b738ae5f726204876f4303c49cfdf4311403fdb3b738ae5f726204876f4303c49cfdf4311403f
linuxlinux>= 23f333a2bfafba80339315b724808982a9de57d9 < a69e617e533edddf3fa3123149900f36e0a6dc74a69e617e533edddf3fa3123149900f36e0a6dc74
linuxlinux_kernel>= 0 < 5.10.140-15.10.140-1
linuxlinux_kernel>= 0 < 6.0.2-16.0.2-1
linuxlinux_kernel>= 0 < 6.0.2-16.0.2-1
linuxlinux_kernel>= 0 < 6.0.2-16.0.2-1
linuxlinux_kernel>= 2.6.38 < 4.9.3264.9.326
linuxlinux_kernel>= 4.10 < 4.14.2914.14.291
linuxlinux_kernel>= 4.15 < 4.19.2564.19.256
linuxlinux_kernel>= 4.20 < 5.4.2115.4.211
linuxlinux_kernel>= 5.11 < 5.15.615.15.61
linuxlinux_kernel>= 5.16 < 5.18.185.18.18
linuxlinux_kernel>= 5.19 < 5.19.25.19.2
linuxlinux_kernel>= 5.5 < 5.10.1375.10.137

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
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