Linux vulnerability

What happened

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 versions

Linux: e9feb58020f952f7d9de785ede9a7d54ab1eda5c through before dd8472526a04f2185afd792b8041a912a7d75d85 (git); e9feb58020f952f7d9de785ede9a7d54ab1eda5c through before 3454c729ee8aa682ec871f1b174b047f731933ae (git); e9feb58020f952f7d9de785ede9a7d54ab1eda5c through before be9b121894d6ad44f0011f79543a2e3245979497 (git); e9feb58020f952f7d9de785ede9a7d54ab1eda5c through before 7d857cf5f0120bb0e020fa20b03bd21b9d3e0c04 (git); e9feb58020f952f7d9de785ede9a7d54ab1eda5c through before d5e2cd2bc8ae36617346b3a54ee9da61d866bf92 (git); e9feb58020f952f7d9de785ede9a7d54ab1eda5c through before fd098a23bf8fda7eae48db9b06e7c34fc4d228fa (git); 5.4 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.