Alignment Issue in Linux Kernel Affecting BPF Programs

CVE-2022-49840

Summary

In the Linux kernel, a vulnerability has been identified that affects BPF programs due to an alignment issue in the skb_shared_info structure. When a user-space BPF program requests an odd size, it leads to unaligned access, which can subsequently trigger a use-after-free read. This can result in data corruption and unexpected behavior within the kernel, potentially impacting system stability. The issue has been addressed by ensuring that the size of allocated data aligns correctly to cache line boundaries, thereby preventing such faults from occurring in future executions.

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