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

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

printk: Fix possible console use-after-free

When emitting a record via legacy printing, it is possible that a handover to another legacy printing context occurs. When a context has performed a handover, the console SRCU read lock is released and the pointer to the console struct might now be invalid. Therefore, after calling nbcon_legacy_emit_next_record() or console_emit_next_record(), it is necessary to check if a handover occurred _before_ further @con usage.

Sashiko pointed out that console_flush_one_record() was not doing this.

In console_flush_one_record(), after emitting a record, move the further usage of @con after the handover check.

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

printk: Fix possible console use-after-free

When emitting a record via legacy printing, it is possible that a handover to another legacy printing context occurs. When a context has performed a handover, the console SRCU read lock is released and the pointer to the console struct might now be invalid. Therefore, after calling nbcon_legacy_emit_next_record() or console_emit_next_record(), it is necessary to check if a handover occurred _before_ further @con usage.

Sashiko pointed out that console_flush_one_record() was not doing this.

In console_flush_one_record(), after emitting a record, move the further usage of @con after the handover check.

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 120 more

In the Linux kernel, the following vulnerability has been resolved: printk: Fix possible console use-after-free When emitting a record via legacy printing, it is possible that a handover to another legacy printing context occurs. When a context has performed a handover, the console SRCU read lock is released and the pointer to the console struct might now be invalid. Therefore, after calling nbcon_legacy_emit_next_record() or console_emit_next_record(), it is necessary to check if a handover occurred _before_ further @con usage. Sashiko pointed out that console_flush_one_record() was not doing this. In console_flush_one_record(), after emitting a record, move the further usage of @con after the handover check.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel möglicherweise ausnutzen, um Berechtigungen zu erweitern, Sicherheitsmaßnahmen zu umgehen, Daten offenzulegen oder zu manipulieren, den Speicher zu beschädigen, Denial-of-Service-Zustände zu verursachen oder andere, nicht näher spezifizierte Angriffe durchzuführen.