Source: linux-image-4.17.0-3-amd64
Version: 4.17.17-1
Severity: normal
A minute or so after booting this kernel within a kvm guest that has
some userspace crypto working in it, i see a message about ratelimited
reports in the kernel ring buffer, but i never get any of the
full messages:
root@test:~# head -v /proc/sys/kernel/printk*
==> /proc/sys/kernel/printk <==
7 4 1 7
==> /proc/sys/kernel/printk_delay <==
0
==> /proc/sys/kernel/printk_devkmsg <==
ratelimit
==> /proc/sys/kernel/printk_ratelimit <==
10
==> /proc/sys/kernel/printk_ratelimit_burst <==
10
root@test:~# cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.17.0-3-amd64
root=UUID=44659876-4a68-4a3a-b3fa-0403eeb0c6ca
ro console=ttyS0,115200n8
root@test:~# dmesg | tail -n 3
[ 2.880287] [drm] Initialized bochs-drm 1.0.0 20130925 for 0000:00:02.0 on
minor 0
[ 107.680402] random: crng init done
[ 107.681132] random: 7 urandom warning(s) missed due to ratelimiting
root@test:~#
given the timing, i presume the urandom warnings have to do with some
process accessing /dev/urandom before the crng is initialized, but
none of them is displayed (not even one, let alone the 10 i'd expect
from the sysctl values).
This is a problem because it makes it harder to figure out which
processes are actually doing the dangerous urandom reads.
This system doesn't have plymouth or anything graphical installed
(it's using a virtualized serial console) so i don't think #897572 is
related.
--dkg
-- System Information:
Debian Release: sid
Architecture: amd64 (x86_64)
Kernel: Linux 4.17.0-3-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
