Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 23f333a2bfafba80339315b724808982a9de57d9 before d2d6b530d89b0a912148018027386aa049f0a309; affected 23f333a2bfafba80339315b724808982a9de57d9 before e2a521a7dcc463c5017b4426ca0804e151faeff7; affected 23f333a2bfafba80339315b724808982a9de57d9 before 7f77dcbc030c2faa6d8e8a594985eeb34018409e; affected 23f333a2bfafba80339315b724808982a9de57d9 before 8b4588b8b00b299be16a35be67b331d8fdba03f3; affected 23f333a2bfafba80339315b724808982a9de57d9 before 135199a2edd459d2b123144efcd7f9bcd95128e4; affected 23f333a2bfafba80339315b724808982a9de57d9 before 635fd8953e4309b54ca6a81bed1d4a87668694f4; affected 23f333a2bfafba80339315b724808982a9de57d9 before d49bb8cf9bfaa06aa527eb30f1a52a071da2e32f; affected 23f333a2bfafba80339315b724808982a9de57d9 before db3b738ae5f726204876f4303c49cfdf4311403f; affected 23f333a2bfafba80339315b724808982a9de57d9 before a69e617e533edddf3fa3123149900f36e0a6dc74 |
| Linux / Linux | affected 2.6.38; unaffected 0 before 2.6.38; unaffected 4.9.326 through 4.9.*; unaffected 4.14.291 through 4.14.*; unaffected 4.19.256 through 4.19.*; unaffected 5.4.211 through 5.4.*; unaffected 5.10.137 through 5.10.*; unaffected 5.15.61 through 5.15.*; unaffected 5.18.18 through 5.18.*; unaffected 5.19.2 through 5.19.*; unaffected 6.0 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/d2d6b530d89b0a912148018027386aa049f0a309
- https://git.kernel.org/stable/c/e2a521a7dcc463c5017b4426ca0804e151faeff7
- https://git.kernel.org/stable/c/7f77dcbc030c2faa6d8e8a594985eeb34018409e
- https://git.kernel.org/stable/c/8b4588b8b00b299be16a35be67b331d8fdba03f3
- https://git.kernel.org/stable/c/135199a2edd459d2b123144efcd7f9bcd95128e4
- https://git.kernel.org/stable/c/635fd8953e4309b54ca6a81bed1d4a87668694f4
- https://git.kernel.org/stable/c/d49bb8cf9bfaa06aa527eb30f1a52a071da2e32f
- https://git.kernel.org/stable/c/db3b738ae5f726204876f4303c49cfdf4311403f
- https://git.kernel.org/stable/c/a69e617e533edddf3fa3123149900f36e0a6dc74