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

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

net: ks8851: Reinstate disabling of BHs around IRQ handler

If the driver executes ks8851_irq() AND a TX packet has been sent, then the driver enables TX queue via netif_wake_queue() which schedules TX softirq to queue packets for this device.

If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by the MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to allocate SKBs for the received packets. If netdev_alloc_skb_ip_align() is called with BH enabled, then local_bh_enable() at the end of netdev_alloc_skb_ip_align() will trigger the pending softirq processing, which may ultimately call the .xmit callback ks8851_start_xmit_par(). The ks8851_start_xmit_par() will try to lock struct ks8851_net_par .lock spinlock, which is already locked by ks8851_irq() from which ks8851_start_xmit_par() was called. This leads to a deadlock, which is reported by the kernel, including a trace listed below.

If CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0 ("net: ks8851: Fix deadlock with the SPI chip variant") the deadlock can also be triggered without received packet in the RX FIFO. The pending softirqs will be processed on return from spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers the deadlock as well.

Fix the problem by disabling BH around critical sections, including the IRQ handler, thus preventing the net_tx_action() softirq from triggering during these critical secti…

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

net: ks8851: Reinstate disabling of BHs around IRQ handler

If the driver executes ks8851_irq() AND a TX packet has been sent, then the driver enables TX queue via netif_wake_queue() which schedules TX softirq to queue packets for this device.

If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by the MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to allocate SKBs for the received packets. If netdev_alloc_skb_ip_align() is called with BH enabled, then local_bh_enable() at the end of netdev_alloc_skb_ip_align() will trigger the pending softirq processing, which may ultimately call the .xmit callback ks8851_start_xmit_par(). The ks8851_start_xmit_par() will try to lock struct ks8851_net_par .lock spinlock, which is already locked by ks8851_irq() from which ks8851_start_xmit_par() was called. This leads to a deadlock, which is reported by the kernel, including a trace listed below.

If CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0 ("net: ks8851: Fix deadlock with the SPI chip variant") the deadlock can also be triggered without received packet in the RX FIFO. The pending softirqs will be processed on return from spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers the deadlock as well.

Fix the problem by disabling BH around critical sections, including the IRQ handler, thus preventing the net_tx_action() softirq from triggering during these critical secti…

kernel-devel-7.0.11-1.1 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 153 more

In the Linux kernel, the following vulnerability has been resolved: net: ks8851: Reinstate disabling of BHs around IRQ handler If the driver executes ks8851_irq() AND a TX packet has been sent, then the driver enables TX queue via netif_wake_queue() which schedules TX softirq to queue packets for this device. If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by the MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to allocate SKBs for the received packets. If netdev_alloc_skb_ip_align() is called with BH enabled, then local_bh_enable() at the end of netdev_alloc_skb_ip_align() will trigger the pending softirq processing, which may ultimately call the .xmit callback ks8851_start_xmit_par(). The ks8851_start_xmit_par() will try to lock struct ks8851_net_par .lock spinlock, which is already locked by ks8851_irq() from which ks8851_start_xmit_par() was called. This leads to a deadlock, which is reported by the kernel, including a trace listed below. If CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0 ("net: ks8851: Fix deadlock with the SPI chip variant") the deadlock can also be triggered without received packet in the RX FIFO. The pending softirqs will be processed on return from spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers the deadlock as well. Fix the problem by disabling BH around critical sections, including the IRQ handler, thus preventing the net_tx_action() softirq from triggering during these critical sections.…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder andere nicht näher spezifizierte Auswirkungen zu erzielen.