Commit 4d2176df29 ("handshake: Allow event handler to free handshake")
introduced a re-entrancy guard so that handshake_state objects that are
destroyed as a result of the event do not cause a crash. It rightly
used a temporary object to store the passed in handshake. Unfortunately
this caused variable shadowing which resulted in crashes fixed by commit
d22b174a73 ("handshake: use _hs directly in handshake_event").
However, since the temporary was no longer used, this fix itself caused
a crash:
#0 0x00005555f0ba8b3d in eapol_handle_ptk_1_of_4 (sm=sm@entry=0x5555f2b4a920, ek=0x5555f2b62588, ek@entry=0x16, unencrypted=unencrypted@entry=false) at src/eapol.c:1236
1236 handshake_event(sm->handshake,
(gdb) bt
#0 0x00005555f0ba8b3d in eapol_handle_ptk_1_of_4 (sm=sm@entry=0x5555f2b4a920, ek=0x5555f2b62588, ek@entry=0x16, unencrypted=unencrypted@entry=false) at src/eapol.c:1236
#1 0x00005555f0bab118 in eapol_key_handle (unencrypted=<optimized out>, frame=<optimized out>, sm=0x5555f2b4a920) at src/eapol.c:2343
#2 eapol_rx_packet (proto=<optimized out>, from=<optimized out>, frame=<optimized out>, unencrypted=<optimized out>, user_data=0x5555f2b4a920) at src/eapol.c:2665
#3 0x00005555f0bac497 in __eapol_rx_packet (ifindex=62, src=src@entry=0x5555f2b62574 "x\212 J\207\267", proto=proto@entry=34958, frame=frame@entry=0x5555f2b62588 "\002\003",
len=len@entry=121, noencrypt=noencrypt@entry=false) at src/eapol.c:3017
#4 0x00005555f0b8c617 in netdev_control_port_frame_event (netdev=0x5555f2b64450, msg=0x5555f2b62588) at src/netdev.c:5574
#5 netdev_unicast_notify (msg=msg@entry=0x5555f2b619a0, user_data=<optimized out>) at src/netdev.c:5613
#6 0x00007f60084c9a51 in dispatch_unicast_watches (msg=0x5555f2b619a0, id=<optimized out>, genl=0x5555f2b3fc80) at ell/genl.c:954
#7 process_unicast (nlmsg=0x7fff61abeac0, genl=0x5555f2b3fc80) at ell/genl.c:973
#8 received_data (io=<optimized out>, user_data=0x5555f2b3fc80) at ell/genl.c:1098
#9 0x00007f60084c61bd in io_callback (fd=<optimized out>, events=1, user_data=0x5555f2b3fd20) at ell/io.c:120
#10 0x00007f60084c536d in l_main_iterate (timeout=<optimized out>) at ell/main.c:478
#11 0x00007f60084c543e in l_main_run () at ell/main.c:525
#12 l_main_run () at ell/main.c:507
#13 0x00007f60084c5670 in l_main_run_with_signal (callback=callback@entry=0x5555f0b89150 <signal_handler>, user_data=user_data@entry=0x0) at ell/main.c:647
#14 0x00005555f0b886a4 in main (argc=<optimized out>, argv=<optimized out>) at src/main.c:532
This happens when the driver does not support rekeying, which causes iwd to
attempt a disconnect and re-connect. The disconnect action is
taken during the event callback and destroys the underlying eapol state
machine. Since a temporary isn't used, attempting to dereference
sm->handshake results in a crash.
Fix this by introducing a UNIQUE_ID macro which should prevent shadowing
and using a temporary variable as originally intended.
Fixes: d22b174a73 ("handshake: use _hs directly in handshake_event")
Fixes: 4d2176df29 ("handshake: Allow event handler to free handshake")
Reported-By: Toke Høiland-Jørgensen <toke@toke.dk>
Tested-by: Toke Høiland-Jørgensen <toke@toke.dk>
Use a constant control flow in the derivation loop, avoiding leakage
in the iteration succesfuly converting the password.
Increase number of iterations (20 to 30) to avoid issues with
passwords needing more iterations.
mschaputil already had similar functionality, but ERP will need this
as well. These two functions will also handle identities with either
'@' or '\' to separate the user and domain.
Use a static buffer for converting an SSID to an approximate string in
UTF8. Replace each char that is not UTF8 compatible with the UTF8
replacement symbol.
James Prestwood