Opened 7 years ago

Closed 7 years ago

Last modified 4 years ago

#9222 closed defect (fixed)

WNDR3700v2: /dev/random unavailable

Reported by: Timo Goebel <mail@…> Owned by: developers
Priority: normal Milestone: Barrier Breaker 14.07
Component: base system Version: Trunk
Keywords: Cc:


When I restart wifi on my self built trunk r26596 version, I get the following errors:

random: Cannot read from /dev/random: Resource temporarily unavailable
random: Only 0/20 bytes of strong random data available from /dev/random
random: Not enough entropy pool available for secure operations
WPA: Not enough entropy in random pool for secure operations - update keys later when the first station connects

This results to wifi being very slow.

A quick fix is to delete /dev/random and create a symlink to /dev/urandom.

Attachments (0)

Change History (5)

comment:1 Changed 7 years ago by Jmeier

Thanks, symlink worked for me!

comment:2 Changed 7 years ago by nbd

  • Resolution set to fixed
  • Status changed from new to closed

When there's not enough secure random data available, hostapd may refuse the first two associations to gather some more entropy to seed the PRNG of /dev/urandom.
I added some code to ensure that entropy gets fed to the kernel and that it creates a stampfile /var/run to mark the random data ready, however this file was not properly created in all cases. Should be fixed at least for restarts in r26611, on the first start it can still print this message and it's normal.

comment:3 Changed 7 years ago by mail@…

I think, that it's very odd, that there is practically no entropy available on the WNDR3700v2.
cat /proc/sys/kernel/random/entropy_avail
always shows 11.

On another openwrt-device (tp-link), the command returns something > 1000.

comment:4 Changed 6 years ago by candrews@…

see #9631 for the lack of entropy on the WNDR3700v2.

comment:5 Changed 4 years ago by jow

  • Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07

Milestone Attitude Adjustment 12.09 deleted

Add Comment

Modify Ticket

as closed .
The resolution will be deleted. Next status will be 'reopened'.

E-mail address and user name can be saved in the Preferences.

Note: See TracTickets for help on using tickets.