发布于3月6日3月6日 Members Ubuntu: (Multiple Advisories) (CVE-2024-35971): Linux kernel vulnerabilities Severity 4 CVSS (AV:L/AC:M/Au:N/C:P/I:P/A:P) Published 05/20/2024 Created 07/12/2024 Added 07/12/2024 Modified 07/29/2024 Description In the Linux kernel, the following vulnerability has been resolved: net: ks8851: Handle softirqs at the end of IRQ thread to fix hang The ks8851_irq() thread may call ks8851_rx_pkts() in case there are any packets in the MAC FIFO, which calls netif_rx(). This netif_rx() implementation is guarded by local_bh_disable() and local_bh_enable(). The local_bh_enable() may call do_softirq() to run softirqs in case any are pending. One of the softirqs is net_rx_action, which ultimately reaches the driver .start_xmit callback. If that happens, the system hangs. The entire call chain is below: ks8851_start_xmit_par from netdev_start_xmit netdev_start_xmit from dev_hard_start_xmit dev_hard_start_xmit from sch_direct_xmit sch_direct_xmit from __dev_queue_xmit __dev_queue_xmit from __neigh_update __neigh_update from neigh_update neigh_update from arp_process.constprop.0 arp_process.constprop.0 from __netif_receive_skb_one_core __netif_receive_skb_one_core from process_backlog process_backlog from __napi_poll.constprop.0 __napi_poll.constprop.0 from net_rx_action net_rx_action from __do_softirq __do_softirq from call_with_stack call_with_stack from do_softirq do_softirq from __local_bh_enable_ip __local_bh_enable_ip from netif_rx netif_rx from ks8851_irq ks8851_irq from irq_thread_fn irq_thread_fn from irq_thread irq_thread from kthread kthread from ret_from_fork The hang happens because ks8851_irq() first locks a spinlock in ks8851_par.c ks8851_lock_par() spin_lock_irqsave(&ksp->lock, ...) and with that spinlock locked, calls netif_rx(). Once the execution reaches ks8851_start_xmit_par(), it calls ks8851_lock_par() again which attempts to claim the already locked spinlock again, and the hang happens. Move the do_softirq() call outside of the spinlock protected section of ks8851_irq() by disabling BHs around the entire spinlock protected section of ks8851_irq() handler. Place local_bh_enable() outside of the spinlock protected section, so that it can trigger do_softirq() without the ks8851_par.c ks8851_lock_par() spinlock being held, and safely call ks8851_start_xmit_par() without attempting to lock the already locked spinlock. Since ks8851_irq() is protected by local_bh_disable()/local_bh_enable() now, replace netif_rx() with __netif_rx() which is not duplicating the local_bh_disable()/local_bh_enable() calls. Solution(s) ubuntu-upgrade-linux-image-6-8-0-1006-gke ubuntu-upgrade-linux-image-6-8-0-1007-intel ubuntu-upgrade-linux-image-6-8-0-1007-raspi ubuntu-upgrade-linux-image-6-8-0-1008-ibm ubuntu-upgrade-linux-image-6-8-0-1008-oem ubuntu-upgrade-linux-image-6-8-0-1008-oracle ubuntu-upgrade-linux-image-6-8-0-1008-oracle-64k ubuntu-upgrade-linux-image-6-8-0-1009-nvidia ubuntu-upgrade-linux-image-6-8-0-1009-nvidia-64k ubuntu-upgrade-linux-image-6-8-0-1010-azure ubuntu-upgrade-linux-image-6-8-0-1010-azure-fde ubuntu-upgrade-linux-image-6-8-0-1010-gcp ubuntu-upgrade-linux-image-6-8-0-1011-aws ubuntu-upgrade-linux-image-6-8-0-38-generic ubuntu-upgrade-linux-image-6-8-0-38-generic-64k ubuntu-upgrade-linux-image-6-8-0-38-lowlatency ubuntu-upgrade-linux-image-6-8-0-38-lowlatency-64k ubuntu-upgrade-linux-image-aws ubuntu-upgrade-linux-image-azure ubuntu-upgrade-linux-image-azure-fde ubuntu-upgrade-linux-image-gcp ubuntu-upgrade-linux-image-generic ubuntu-upgrade-linux-image-generic-64k ubuntu-upgrade-linux-image-generic-64k-hwe-24-04 ubuntu-upgrade-linux-image-generic-hwe-24-04 ubuntu-upgrade-linux-image-generic-lpae ubuntu-upgrade-linux-image-gke ubuntu-upgrade-linux-image-ibm ubuntu-upgrade-linux-image-ibm-classic ubuntu-upgrade-linux-image-ibm-lts-24-04 ubuntu-upgrade-linux-image-intel ubuntu-upgrade-linux-image-kvm ubuntu-upgrade-linux-image-lowlatency ubuntu-upgrade-linux-image-lowlatency-64k ubuntu-upgrade-linux-image-nvidia ubuntu-upgrade-linux-image-nvidia-64k ubuntu-upgrade-linux-image-oem-24-04 ubuntu-upgrade-linux-image-oem-24-04a ubuntu-upgrade-linux-image-oracle ubuntu-upgrade-linux-image-oracle-64k ubuntu-upgrade-linux-image-raspi ubuntu-upgrade-linux-image-virtual ubuntu-upgrade-linux-image-virtual-hwe-24-04 References https://attackerkb.com/topics/cve-2024-35971 CVE - 2024-35971 USN-6893-1 USN-6893-2 USN-6893-3 USN-6918-1
