CVS commit: src/sys/net

["Shoichi YAMAGUCHI" <yamaguchi%netbsd.org@localhost>]

Module Name:    src
Committed By:   yamaguchi
Date:           Mon Jun 18 09:49:05 UTC 2018

Modified Files:
        src/sys/net: if_pppoe.c

Log Message:
Fix not to use PPPOE_UNLOCK before acccess to pppoe_softc
to avoid a race condition

According to the locking order of pppoe(4), the access to
pppoe_softc has to follow 5 steps as below.

1. aquire pppoe_softc_list_lock
2. aquire pppoe_softc lock
3. release pppoe_softc_list_lock
4. access to pppoe_softc
5. release pppoe_softc lock

However, pppoe_dispatch_disc_pkt() releases the lock of pppoe_softc
temporarily, and then re-aquires it before step 4 of the adove. So,
it is possible for other contexts to destroy a pppoe_softc in the
interim.
To fix this condition, avoid PPPOE_UNLOCK with the problem.

ok by knakahara@n.o


To generate a diff of this commit:
cvs rdiff -u -r1.138 -r1.139 src/sys/net/if_pppoe.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.