FWIW, I am unable to repro this in our 4.19 kernel [1]. I put mem=4G on the command line, and can dd till the cows come home. Seems like you're leaking buffers somewhere? localhost ~ # dd if=/dev/sda of=/dev/null bs=4M status=progress 12683575296 bytes (13 GB, 12 GiB) copied, 125.004 s, 101 MB/s^C 3048+0 records in 3047+0 records out 12780044288 bytes (13 GB, 12 GiB) copied, 126.015 s, 101 MB/s -Evan [1] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.19
