ipv6 link local address of bridge changes every time network restarts

[hayate]

I have a OpenWrt box with he.net ipv6 tunnel set up, but I have a question about link-local address.

Say I have a bridge interface combining eth and wl.
Since the bridge has the same MAC as its sub-interface, why does its link-local address always change while the Ethernet interface stay fixed??

Here is my ifconfig output:

br-lan    Link encap:Ethernet  HWaddr 00:1F:A3:42:0C:66
         inet addr:10.1.2.1  Bcast:10.1.2.255  Mask:255.255.255.0
         inet6 addr: 2001:470:xx:xx::1/64 Scope:Global
         inet6 addr: fe80::44e0:94ff:fe89:e90c/64 Scope:Link
         UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         RX packets:82278 errors:0 dropped:0 overruns:0 frame:0
         TX packets:62878 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:0
         RX bytes:82232425 (78.4 MiB)  TX bytes:10346853 (9.8 MiB)

eth1      Link encap:Ethernet  HWaddr 00:1F:A3:42:0C:66
         inet6 addr: fe80::21f:a3ff:fe42:c66/64 Scope:Link
         UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         RX packets:63868242 errors:19 dropped:0 overruns:19 frame:0
         TX packets:60061164 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:1000
         RX bytes:4270648157 (3.9 GiB)  TX bytes:1774584611 (1.6 GiB)
         Interrupt:14

eth1.0    Link encap:Ethernet  HWaddr 00:1F:A3:42:0C:66
         inet6 addr: fe80::21f:a3ff:fe42:c66/64 Scope:Link
         UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         RX packets:30757775 errors:0 dropped:0 overruns:0 frame:0
         TX packets:32515825 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:0
         RX bytes:1736056390 (1.6 GiB)  TX bytes:1386907948 (1.2 GiB)

note that br-lan's link local address is different from the others.
Is this normal? Cant the bridge link local address be fixed?
thanks

[snarked]

Turn off the privacy extension.

[chrismb]

Turn off the privacy extension.

I'm pretty sure that it has nothing to do with privacy extensions.
I have the same problem as the OP.
/proc/sys/net/ipv6/conf/*/use_tempaddr is 0 for all interfaces.
So they're disabled.
Yet br-lan almost always gets a new address at reboot.
Am I missing something?

The bad thing is that my OpenWRT device has a flaky radio.  It crashes
every once in a while, and a stale default route lingers after the router
is rebooted.