On 10/13/2023 10:44 AM, Kanchan Joshi wrote: > User can specify a smaller meta buffer than what the device is > wired to update/access. Kernel makes a copy of the meta buffer into > which the device does DMA. > As a result, the device overwrites the unrelated kernel memory, causing > random kernel crashes. > > Same issue is possible for extended-lba case also. When user specifies a > short unaligned buffer, the kernel makes a copy and uses that for DMA. > > Detect these situations and prevent corruption for unprivileged user > passthrough. No change to status-quo for privileged/root user. > > Fixes: 63263d60e0f9 ("nvme: Use metadata for passthrough commands") Since change is only for unprivileged user, I should have changed this 'Fixes:' to point to this patch instead: 5b7717f44b1 (nvme: fine-granular CAP_SYS_ADMIN for nvme io commands)