{"id":"AZL-88731","summary":"CVE-2026-46031 affecting package kernel for versions less than 6.6.141.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ks8851: Reinstate disabling of BHs around IRQ handler\n\nIf the driver executes ks8851_irq() AND a TX packet has been sent, then\nthe driver enables TX queue via netif_wake_queue() which schedules TX\nsoftirq to queue packets for this device.\n\nIf CONFIG_PREEMPT_RT=y is set AND a packet has also been received by\nthe MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to\nallocate SKBs for the received packets. If netdev_alloc_skb_ip_align()\nis called with BH enabled, then local_bh_enable() at the end of\nnetdev_alloc_skb_ip_align() will trigger the pending softirq processing,\nwhich may ultimately call the .xmit callback ks8851_start_xmit_par().\nThe ks8851_start_xmit_par() will try to lock struct ks8851_net_par\n.lock spinlock, which is already locked by ks8851_irq() from which\nks8851_start_xmit_par() was called. This leads to a deadlock, which\nis reported by the kernel, including a trace listed below.\n\nIf CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0\n(\"net: ks8851: Fix deadlock with the SPI chip variant\") the deadlock\ncan also be triggered without received packet in the RX FIFO. The\npending softirqs will be processed on return from\nspin_unlock_bh(&ks-\u003estatelock) in ks8851_irq(), which triggers the\ndeadlock as well.\n\nFix the problem by disabling BH around critical sections, including the\nIRQ handler, thus preventing the net_tx_action() softirq from triggering\nduring these critical sections. The net_tx_action() softirq is triggered\nonce BH are re-enabled and at the end of the IRQ handler, once all the\nother IRQ handler actions have been completed.\n\n __schedule from schedule_rtlock+0x1c/0x34\n schedule_rtlock from rtlock_slowlock_locked+0x548/0x904\n rtlock_slowlock_locked from rt_spin_lock+0x60/0x9c\n rt_spin_lock from ks8851_start_xmit_par+0x74/0x1a8\n ks8851_start_xmit_par from netdev_start_xmit+0x20/0x44\n netdev_start_xmit from dev_hard_start_xmit+0xd0/0x188\n dev_hard_start_xmit from sch_direct_xmit+0xb8/0x25c\n sch_direct_xmit from __qdisc_run+0x1f8/0x4ec\n __qdisc_run from qdisc_run+0x1c/0x28\n qdisc_run from net_tx_action+0x1f0/0x268\n net_tx_action from handle_softirqs+0x1a4/0x270\n handle_softirqs from __local_bh_enable_ip+0xcc/0xe0\n __local_bh_enable_ip from __alloc_skb+0xd8/0x128\n __alloc_skb from __netdev_alloc_skb+0x3c/0x19c\n __netdev_alloc_skb from ks8851_irq+0x388/0x4d4\n ks8851_irq from irq_thread_fn+0x24/0x64\n irq_thread_fn from irq_thread+0x178/0x28c\n irq_thread from kthread+0x12c/0x138\n kthread from ret_from_fork+0x14/0x28","modified":"2026-08-28T17:48:05.522483427Z","published":"2026-05-27T14:17:22Z","upstream":["CVE-2026-46031"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46031"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.141.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-88731.json"}}],"schema_version":"1.9.0"}