sbsndptr panic on recent 9-CURRENT

I just upgraded to:

FreeBSD jclarke-pc.cisco.com 9.0-CURRENT FreeBSD 9.0-CURRENT #6: Mon Oct
12 14:23:45 EDT 2009
marcus_at_jclarke-pc.cisco.com:/usr/obj/usr/src/sys/JCLARKE-PC  i386

A few minutes after a reboot, I see:

panic: sbsndptr: sockbuf 0xc5ba7c2c and mbuf 0xc5471300 clashing

#3  0xc0667c1a in sbsndptr (sb=0xc5ba7c2c, off=Variable "off" is not
available.
)
    at /usr/src/sys/kern/uipc_sockbuf.c:954
#4  0xc0755724 in tcp_output (tp=0xc5ab2000)
    at /usr/src/sys/netinet/tcp_output.c:814
#5  0xc0762b4a in tcp_usr_send (so=0xc5ba7b44, flags=0, m=0xc5471300,
nam=0x0,
    control=0x0, td=0xc55ef8c0) at tcp_offload.h:282
#6  0xc066ded5 in sosend_generic (so=0xc5ba7b44, addr=0x0, uio=0xe7a62c58,
    top=0xc5471300, control=0x0, flags=0, td=0xc55ef8c0)
    at /usr/src/sys/kern/uipc_socket.c:1265
#7  0xc06697df in sosend (so=0xc5ba7b44, addr=0x0, uio=0xe7a62c58, top=0x0,
    control=0x0, flags=0, td=0xc55ef8c0)
    at /usr/src/sys/kern/uipc_socket.c:1309
#8  0xc064f343 in soo_write (fp=0xc5ad84d0, uio=0xe7a62c58,
    active_cred=0xc5bb4600, flags=0, td=0xc55ef8c0)
    at /usr/src/sys/kern/sys_socket.c:102
#9  0xc0648dd7 in dofilewrite (td=0xc55ef8c0, fd=3, fp=0xc5ad84d0,
    auio=0xe7a62c58, offset=-1, flags=0) at file.h:239
#10 0xc06490c8 in kern_writev (td=0xc55ef8c0, fd=3, auio=0xe7a62c58)
    at /usr/src/sys/kern/sys_generic.c:446
#11 0xc064914f in write (td=0xc55ef8c0, uap=0xe7a62cf8)
    at /usr/src/sys/kern/sys_generic.c:362
#12 0xc089f765 in syscall (frame=0xe7a62d38)
    at /usr/src/sys/i386/i386/trap.c:1078
#13 0xc0882440 in Xint0x80_syscall () at
/usr/src/sys/i386/i386/exception.s:261
#14 0x00000033 in ?? ()

This machine uses em, gif, and PPP (tun) interfaces (with IPv4 and v6
addresses).  I have since rebooted, so it may not be possible to provide
many more details from this crash.  However, if I see the crash again,
is there anything more I should provide?

Joe

-- 
Joe Marcus Clarke
FreeBSD GNOME Team	::	gnome_at_FreeBSD.org
FreeNode / #freebsd-gnome
http://www.FreeBSD.org/gnome