CVE-2024-36908

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: blk-iocost: no ADVERTIR si iocg ya estaba desconectado. En iocg_pay_debt(), se activa una advertencia si 'active_list' está vacía, lo que pretende confirmar que iocg está activo cuando deuda. Sin embargo, se puede activar una advertencia durante un blkcg o la eliminación de un disco, si se ejecuta iocg_waitq_timer_fn() en ese momento: ADVERTENCIA: CPU: 0 PID: 2344971 en block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190 Seguimiento de llamadas: iocg_pay_debt +0x14c/0x190 iocg_kick_waitq+0x438/0x4c0 iocg_waitq_timer_fn+0xd8/0x130 __run_hrtimer+0x144/0x45c __hrtimer_run_queues+0x16c/0x244 hrtimer_interrupt+0x2cc/0x7b0 La advertencia en esta situación es sin sentido. Dado que este iocg se está eliminando, el estado de 'active_list' es irrelevante y 'waitq_timer' se cancela después de eliminar 'active_list' en ioc_pd_free(), lo que garantiza que iocg se libere después de que iocg_waitq_timer_fn() regrese. Por lo tanto, agregue la verificación si iocg ya estaba desconectado para evitar advertencias al eliminar un blkcg o un disco.

In the Linux kernel, the following vulnerability has been resolved: blk-iocost: do not WARN if iocg was already offlined In iocg_pay_debt(), warn is triggered if 'active_list' is empty, which is intended to confirm iocg is active when it has debt. However, warn can be triggered during a blkcg or disk removal, if iocg_waitq_timer_fn() is run at that time: WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190 Call trace: iocg_pay_debt+0x14c/0x190 iocg_kick_waitq+0x438/0x4c0 iocg_waitq_timer_fn+0xd8/0x130 __run_hrtimer+0x144/0x45c __hrtimer_run_queues+0x16c/0x244 hrtimer_interrupt+0x2cc/0x7b0 The warn in this situation is meaningless. Since this iocg is being removed, the state of the 'active_list' is irrelevant, and 'waitq_timer' is canceled after removing 'active_list' in ioc_pd_free(), which ensures iocg is freed after iocg_waitq_timer_fn() returns. Therefore, add the check if iocg was already offlined to avoid warn when removing a blkcg or disk.

Benedict Schlüter, Supraja Sridhara, Andrin Bertschi, and Shweta Shinde discovered that an untrusted hypervisor could inject malicious #VC interrupts and compromise the security guarantees of AMD SEV-SNP. This flaw is known as WeSee. A local attacker in control of the hypervisor could use this to expose sensitive information or possibly execute arbitrary code in the trusted execution environment. Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system.