Christoph Hellwig

The issue is related to a race condition in the `dmam free coherent()` function, which can lead to data corruption and crashes. This occurs when a concurrent task makes an allocation with the same `vaddr` and adds it to the devres list between the time `dmam free coherent()` frees a DMA allocation and calls `devres destroy()` to remove and free the data structure used to track the DMA allocation. As a result, there can be two entries in the devres list with the same `vaddr`, and `devres destroy()` can free the wrong entry, triggering the `WARN ON()` in `dmam match`. The fix involves destroying the devres entry before freeing the DMA allocation.

The issue is related to the initialization of the integrity buffer in the Linux kernel. Metadata added by `bio integrity prep` uses plain `kmalloc`, which leads to random kernel memory being written to media. For PI metadata, this is limited to the app tag that isn't used by kernel-generated metadata, but for non-PI metadata, the entire buffer leaks kernel memory. The fix involves adding the ` GFP ZERO` flag to allocations for writes.

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.

تم تحديد مشكلة في نواة لينكس حيث يمكن أن تعمل الدالة `bfq merge bio()` بمعلومات cgroup قديمة عند ترحيل عملية إلى cgroup مختلفة. قد يؤدي ذلك إلى دمج bio مع طلب من cgroup مختلفة، أو دمج `bfqqs` لـ cgroups مختلفة، مما قد يتسبب في مشكلات الاستخدام بعد التحرير (use-after-free).