CVE-2022-48840

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: iavf: corrige el bloqueo durante el reinicio/apagado. El commit reciente 974578017fc1 ("iavf: agrega espera para que el puerto se inicialice en eliminar") agrega un bucle de espera al comienzo de iavf_remove() para garantizar que la inicialización del puerto finalice antes de cancelar el registro del dispositivo de red. Esto provoca una regresión en el escenario de reinicio/apagado porque en este caso se llama a la devolución de llamada iavf_shutdown() y esta devolución de llamada desconecta el dispositivo, lo desactiva si se está ejecutando y establece su estado en __IAVF_REMOVE. Posteriormente se llama a la devolución de llamada de apagado del controlador PF asociado (por ejemplo, ice_shutdown). Esa devolución de llamada llama, entre otras cosas, a sriov_disable() que llama indirectamente a iavf_remove() (consulte el seguimiento de la pila a continuación). Como el estado del adaptador ya es __IAVF_REMOVE, el bucle mencionado no tiene fin y el proceso de apagado se bloquea. El parche soluciona este problema verificando el estado del adaptador al comienzo de iavf_remove() y omite el resto de la función si el adaptador ya está en estado de eliminación (el apagado está en curso). Reproductor: 1. Cree VF en PF controlado por el controlador ice o i40e 2. Asegúrese de que el VF esté vinculado al controlador iavf 3. Reinicie [52625.981294] sysrq: SysRq: Mostrar estado bloqueado [52625.988377] tarea: estado de reinicio: pila D: 0 pid:17359 ppid: 1 f2 [52625.996732] Seguimiento de llamadas: [52625.999187] __schedule+0x2d1/0x830 [52626.007400] Schedule+0x35/0xa0 [52626.010545] Schedule_hrtimeout_range_clock+0x83/0x100 2626.020046] usleep_range+0x5b/0x80 [52626.023540] iavf_remove+ 0x63/0x5b0 [iavf] [52626.027645] pci_device_remove+0x3b/0xc0 [52626.031572] device_release_driver_internal+0x103/0x1f0 [52626.036805] pci_stop_bus_device+0x72/0xa0 [52626. 040904] pci_stop_and_remove_bus_device+0xe/0x20 [52626.045870] pci_iov_remove_virtfn+0xba/0x120 [52626.050232] sriov_disable +0x2f/0xe0 [52626.053813] ice_free_vfs+0x7c/0x340 [hielo] [52626.057946] ice_remove+0x220/0x240 [hielo] [52626.061967] ice_shutdown+0x16/0x50 [52626.06598 7] pci_device_shutdown+0x34/0x60 [52626.070086] dispositivo_shutdown+ 0x165/0x1c5 [52626.074011] kernel_restart+0xe/0x30 [52626.077593] __do_sys_reboot+0x1d2/0x210 [52626.093815] do_syscall_64+0x5b/0x1a0 [52626.097483] entrada_SYSCALL_64_after_hwframe+0x65/0xca

In the Linux kernel, the following vulnerability has been resolved: iavf: Fix hang during reboot/shutdown Recent commit 974578017fc1 ("iavf: Add waiting so the port is initialized in remove") adds a wait-loop at the beginning of iavf_remove() to ensure that port initialization is finished prior unregistering net device. This causes a regression in reboot/shutdown scenario because in this case callback iavf_shutdown() is called and this callback detaches the device, makes it down if it is running and sets its state to __IAVF_REMOVE. Later shutdown callback of associated PF driver (e.g. ice_shutdown) is called. That callback calls among other things sriov_disable() that calls indirectly iavf_remove() (see stack trace below). As the adapter state is already __IAVF_REMOVE then the mentioned loop is end-less and shutdown process hangs. The patch fixes this by checking adapter's state at the beginning of iavf_remove() and skips the rest of the function if the adapter is already in remove state (shutdown is in progress). Reproducer: 1. Create VF on PF driven by ice or i40e driver 2. Ensure that the VF is bound to iavf driver 3. Reboot [52625.981294] sysrq: SysRq : Show Blocked State [52625.988377] task:reboot state:D stack: 0 pid:17359 ppid: 1 f2 [52625.996732] Call Trace: [52625.999187] __schedule+0x2d1/0x830 [52626.007400] schedule+0x35/0xa0 [52626.010545] schedule_hrtimeout_range_clock+0x83/0x100 [52626.020046] usleep_range+0x5b/0x80 [52626.023540] iavf_remove+0x63/0x5b0 [iavf] [52626.027645] pci_device_remove+0x3b/0xc0 [52626.031572] device_release_driver_internal+0x103/0x1f0 [52626.036805] pci_stop_bus_device+0x72/0xa0 [52626.040904] pci_stop_and_remove_bus_device+0xe/0x20 [52626.045870] pci_iov_remove_virtfn+0xba/0x120 [52626.050232] sriov_disable+0x2f/0xe0 [52626.053813] ice_free_vfs+0x7c/0x340 [ice] [52626.057946] ice_remove+0x220/0x240 [ice] [52626.061967] ice_shutdown+0x16/0x50 [ice] [52626.065987] pci_device_shutdown+0x34/0x60 [52626.070086] device_shutdown+0x165/0x1c5 [52626.074011] kernel_restart+0xe/0x30 [52626.077593] __do_sys_reboot+0x1d2/0x210 [52626.093815] do_syscall_64+0x5b/0x1a0 [52626.097483] entry_SYSCALL_64_after_hwframe+0x65/0xca