[Qemu-devel] slirp-related crash

["Michael S. Tsirkin" <mst@redhat.com>]

It seems somewhat easy to crash qemu with slirp if we queue multiple packets.
I didn't investigate further yet so I don't know if this
is a regression. Anyone knowledgeable about slirp wants to take a look?

/home/mst/qemu-test/bin/qemu-system-x86_64  -enable-kvm -m 1G -drive
file=/home/mst/rhel6.qcow2 -netdev user,id=bar -net
nic,netdev=bar,model=e1000,macaddr=52:54:00:12:34:57  -redir
tcp:8022::22  -vnc :1 -monitor stdio

While guest is booting, quickly do this

ssh localhost -p 8022
CTRL-C
ssh localhost -p 8022
CTRL-C
ssh localhost -p 8022
CTRL-C
ssh localhost -p 8022
CTRL-C

When guest triest to bring up link,
qemu crashes:

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7e4f8a7 in slirp_insque (a=0x0, b=0x7ffff91681f0) at
slirp/misc.c:27
27              element->qh_link = head->qh_link;
(gdb) where
#0  0x00007ffff7e4f8a7 in slirp_insque (a=0x0, b=0x7ffff91681f0) at
slirp/misc.c:27
#1  0x00007ffff7e4ddd8 in if_start (slirp=0x7ffff8b0e4f0) at
slirp/if.c:194
#2  0x00007ffff7e51290 in slirp_select_poll (readfds=0x7fffffffdfe0,
writefds=
    0x7fffffffdf60, xfds=0x7fffffffdee0, select_error=0) at
slirp/slirp.c:588
#3  0x00007ffff7e114c3 in main_loop_wait (nonblocking=<value optimized
out>)
    at main-loop.c:466
#4  0x00007ffff7e09ed4 in main_loop (argc=<value optimized out>, 
    argv=<value optimized out>, envp=<value optimized out>)
    at /home/mst/scm/qemu/vl.c:1482
#5  main (argc=<value optimized out>, argv=<value optimized out>, 
    envp=<value optimized out>) at /home/mst/scm/qemu/vl.c:3525
(gdb) p element
$1 = (struct quehead *) 0x0


-- 
MST