>Number:         176667
>Category:       kern
>Synopsis:       libalias locks on uninitalized data
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Mar 05 16:00:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Lutz Donnerhacke
>Release:        FreeBSD 8.3-RELEASE (GENERIC)
>Organization:
IKS Service GmbH
>Environment:
FreeBSD server7.net.encoline.de 8.3-RELEASE FreeBSD 8.3-RELEASE #0: Mon Apr  9 
21:23:18 UTC 2012     r...@mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  
amd64

>Description:
While testing terminating a huge number of PPPoX clients the kernel panics 
while doing in-kernel NAT.

#4 0xffffffff808e8775 at calltrap+0x8
#5 0xffffffff80fa0f01 at HouseKeeping+0xa1
#6 0xffffffff80f9e6ab at LibAliasOutLocked+0x3b

Please note, that the stack trace is incomplete. There are calls to 
IncrementalCleanup() and DeleteLink(), which are not reported in the stack 
trace.

The problem seems to come from incorrect locking, so the contents of the 
libalias database get corrupted.

This patch might be not the full solution, but is an obvious fix for an obvious 
bug.
>How-To-Repeat:
Setting up ipfw nat, add more then 9000 clients using mpd5.6, generate traffic
>Fix:
--- sys/netinet/libalias/alias_db.c.ORIG        2013-03-05 16:49:13.000000000 
+0100
+++ sys/netinet/libalias/alias_db.c     2013-03-05 16:50:09.000000000 +0100
@@ -2767,8 +2767,8 @@
        struct ip_fw rule;      /* On-the-fly built rule */
        int fwhole;             /* Where to punch hole */

-       LIBALIAS_LOCK_ASSERT(la);
        la = lnk->la;
+       LIBALIAS_LOCK_ASSERT(la);

 /* Don't do anything unless we are asked to */
        if (!(la->packetAliasMode & PKT_ALIAS_PUNCH_FW) ||
@@ -2841,8 +2841,8 @@
 {
        struct libalias *la;

-       LIBALIAS_LOCK_ASSERT(la);
        la = lnk->la;
+       LIBALIAS_LOCK_ASSERT(la);
        if (lnk->link_type == LINK_TCP) {
                int fwhole = lnk->data.tcp->fwhole;     /* Where is the firewall
                                                         * hole? */



>Release-Note:
>Audit-Trail:
>Unformatted:
_______________________________________________
freebsd-bugs@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-bugs
To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"

Reply via email to