On Thu, Apr 5, 2018 at 2:56 AM, Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx> wrote: > Hi. > > 04.04.2018 23:25, Kees Cook wrote: >> >> Thanks for the report! I hope someone more familiar with sg_io() can >> help explain the changing buffer offset... :P > > > Also, FYI, I kept the server running with smartctl periodically invoked, and > it was still triggering BUGs, however, I consider them to be more or less > harmless until the server got stuck with high I/O wait this morning after > next smartctl invocation. So, it isn't harmless, it seems… > > It could be unrelated, of course, since the journal didn't give me any hint > (or a stack trace) on what happened, thus I'll monitor how things behave > without smartctl too. I had a VM running over night with: [1] Running while :; do smartctl -a /dev/sda > /dev/null; done & [2]- Running while :; do ls --color=auto -lR / > /dev/null 2> /dev/null; done & [3]+ Running while :; do sleep $(( $RANDOM % 100 )); sync; echo 3 > /proc/sys/vm/drop_caches; done & and I haven't seen the issue. :( FWIW, I'm using the ahci qemu driver: -drive file=disk-image.raw,if=none,id=drive0,format=raw \ -device ahci,id=bus0 \ -device ide-drive,bus=bus0.0,drive=drive0 Does this match your qemu instance? -Kees -- Kees Cook Pixel Security