CVE-2026-68286

About vulnerability

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

drop_monitor: perform u64_stats updates under IRQ-disabled section

In net_dm_packet_trace_kfree_skb_hit() and net_dm_hw_trap_packet_probe(), u64_stats_update_begin() / u64_stats_inc() / u64_stats_update_end() were called after spin_unlock_irqrestore(&…drop_queue.lock, flags), when local IRQs had already been re-enabled.

Tracepoint probes can execute in IRQ or softirq context. On 32-bit architectures, u64_stats_update_begin() disables preemption but not interrupts, relying on seqcount writes. If a nested interrupt occurs on the same CPU during the 64-bit stats update, the reentrant seqcount update can corrupt the seqcount state or stats value.

Fix this by performing the 64-bit per-CPU stats update before releasing drop_queue.lock via spin_unlock_irqrestore(), ensuring local interrupts remain disabled during the u64_stats update.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 20.04 ELS

Affected packages:

linux @ 4.19.0 (+10 more)

Live-patch status from KernelCare for each operating system.