Petr Tesarik

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue is related to a functional regression in the Linux kernel's swiotlb component, which causes double-allocation of slots due to broken alignment handling. This can lead to buffer corruption and/or a hang when using vsock in a virtual machine with a restricted DMA SWIOTLB pool. The problem occurs because swiotlb alloc() expects a page-aligned allocation but returns a pointer to the 'struct page' corresponding to the allocation, resulting in double-allocation of the first half of the 4KiB page. The issue is resolved by treating the allocation alignment separately from any additional alignment requirements from the device. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue is related to the protection of updates of 64-bit statistics counters in the Linux kernel. A comment in <linux/u64 stats sync.h> explains that the write side of struct u64 stats sync must ensure mutual exclusion, or one seqcount update could be lost on 32-bit platforms, thus blocking readers forever. Such lockups have been observed in real-world scenarios after stmmac xmit() on one CPU raced with stmmac napi poll tx() on another CPU. The fix involves splitting the statics into three parts: fields updated only under the tx queue lock, fields updated only during NAPI poll, and fields updated only from interrupt context. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.