Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

nfc: nci: Fix race between rfkill and nci_unregister_device().

syzbot reported the splat below [0] without a repro.

It indicates that struct nci_dev.cmd_wq had been destroyed before nci_close_device() was called via rfkill.

nci_dev.cmd_wq is only destroyed in nci_unregister_device(), which (I think) was called from virtual_ncidev_close() when syzbot close()d an fd of virtual_ncidev.

The problem is that nci_unregister_device() destroys nci_dev.cmd_wq first and then calls nfc_unregister_device(), which removes the device from rfkill by rfkill_unregister().

So, the device is still visible via rfkill even after nci_dev.cmd_wq is destroyed.

Let's unregister the device from rfkill first in nci_unregister_device().

Note that we cannot call nfc_unregister_device() before nci_close_device() because

1) nfc_unregister_device() calls device_del() which frees all memory allocated by devm_kzalloc() and linked to ndev->conn_info_list

2) nci_rx_work() could try to queue nci_conn_info to ndev->conn_info_list which could be leaked

Thus, nfc_unregister_device() is split into two functions so we can remove rfkill interfaces only before nci_close_device().

[0]: DEBUG_LOCKS_WARN_ON(1) WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: syz.0.8675/6349 WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU…

In the Linux kernel, the following vulnerability has been resolved:

nfc: nci: Fix race between rfkill and nci_unregister_device().

syzbot reported the splat below [0] without a repro.

It indicates that struct nci_dev.cmd_wq had been destroyed before nci_close_device() was called via rfkill.

nci_dev.cmd_wq is only destroyed in nci_unregister_device(), which (I think) was called from virtual_ncidev_close() when syzbot close()d an fd of virtual_ncidev.

The problem is that nci_unregister_device() destroys nci_dev.cmd_wq first and then calls nfc_unregister_device(), which removes the device from rfkill by rfkill_unregister().

So, the device is still visible via rfkill even after nci_dev.cmd_wq is destroyed.

Let's unregister the device from rfkill first in nci_unregister_device().

Note that we cannot call nfc_unregister_device() before nci_close_device() because

1) nfc_unregister_device() calls device_del() which frees all memory allocated by devm_kzalloc() and linked to ndev->conn_info_list

2) nci_rx_work() could try to queue nci_conn_info to ndev->conn_info_list which could be leaked

Thus, nfc_unregister_device() is split into two functions so we can remove rfkill interfaces only before nci_close_device().

[0]: DEBUG_LOCKS_WARN_ON(1) WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: syz.0.8675/6349 WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU…

Security update for the Linux Kernel

Security update for the Linux Kernel

Affected: Ubuntu:Pro:14.04:LTS: linux, Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe and 231 more

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: Fix race between rfkill and nci_unregister_device(). syzbot reported the splat below [0] without a repro. It indicates that struct nci_dev.cmd_wq had been destroyed before nci_close_device() was called via rfkill. nci_dev.cmd_wq is only destroyed in nci_unregister_device(), which (I think) was called from virtual_ncidev_close() when syzbot close()d an fd of virtual_ncidev. The problem is that nci_unregister_device() destroys nci_dev.cmd_wq first and then calls nfc_unregister_device(), which removes the device from rfkill by rfkill_unregister(). So, the device is still visible via rfkill even after nci_dev.cmd_wq is destroyed. Let's unregister the device from rfkill first in nci_unregister_device(). Note that we cannot call nfc_unregister_device() before nci_close_device() because 1) nfc_unregister_device() calls device_del() which frees all memory allocated by devm_kzalloc() and linked to ndev->conn_info_list 2) nci_rx_work() could try to queue nci_conn_info to ndev->conn_info_list which could be leaked Thus, nfc_unregister_device() is split into two functions so we can remove rfkill interfaces only before nci_close_device(). [0]: DEBUG_LOCKS_WARN_ON(1) WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: syz.0.8675/6349 WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU#0: syz.0.86…

Ein Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um nicht näher spezifizierte Angriffe durchzuführen, die möglicherweise zu einer Denial-of-Service- Bedingung führen oder eine Speicherbeschädigung verursachen können.