Bug#897572: urandom hang in early boot
On 08/05/18 05:34, Laurent Bigonville wrote:
Apparently it's also happening for other applications that are starting
later during the boot like GDM.
Somebody has reported an issue on IRC where GDM was taking upto 8
minutes to start (dmesg was showing several "random: systemd:
uninitialized urandom read (16 bytes read)" during boot)
That problem might impact lot of people I'm afraid.
systemd is the underlying cause: plymouthd uses libudev1, which expects
getrandom/urandom(?) to never block:
https://github.com/systemd/systemd/blob/master/src/basic/random-util.c#L34
See discussion here about systemd usage of random numbers:
systemd reads from urandom before initialization
https://github.com/systemd/systemd/issues/4167
The new problem is that 43838a23a05f ("random: fix crng_ready() test")
turns an ugly warning and cryptographic weakness into an indefinite
hang. Security achieved!
Kind regards,
--
Ben Caradoc-Davies <ben@transient.nz>
Director
Transient Software Limited <https://transient.nz/>
New Zealand
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