Date: Sun, 24 Apr 2022 06:30:34 -0800 From: Rob Wing <rob.fx907@gmail.com> To: Warner Losh <imp@bsdimp.com> Cc: Eugene Grosbein <eugen@grosbein.net>, Marek Zarychta <zarychtam@plan-b.pwste.edu.pl>, FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: kernel crash making a vlan on a wlan Message-ID: <CAF3%2Bn_c_3bF4aaBVsLOSJ8GhKmcQjujAC=gAvjjDhDHT%2BmzN8A@mail.gmail.com> In-Reply-To: <CANCZdfq4W1r2Jd2kSLvdg00ACHqSZYQZJhYPAz77%2BsMBgcSBhw@mail.gmail.com> References: <f08424d6-e209-928b-9927-3cc6c0aabb22@hesiod.org> <421d0c0d-4109-3370-9147-85168051deed@freebsd.org> <9ea3536e-b501-3684-850e-65f95fddf2e7@freebsd.org> <28c9ea32-b913-c153-005b-a62d6a7a6f4e@plan-b.pwste.edu.pl> <113d6d4d-eb23-30b1-a9e7-5a82a46604f8@grosbein.net> <CAF3%2Bn_dr1yeZnJkmyn3EBwSPfR%2BvQqT5h%2BtxtWp1=J5t0%2BD2Vg@mail.gmail.com> <CANCZdfq4W1r2Jd2kSLvdg00ACHqSZYQZJhYPAz77%2BsMBgcSBhw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--0000000000002094fe05dd674e87 Content-Type: text/plain; charset="UTF-8" What do you mean when you say they are the same thing? On Sun, Apr 24, 2022 at 5:35 AM Warner Losh <imp@bsdimp.com> wrote: > > > On Sun, Apr 24, 2022, 1:03 AM Rob Wing <rob.fx907@gmail.com> wrote: > >> From what I can tell, the vlan driver is calling ieee80211_output() with >> the wrong ifnet context and dereferencing a bad pointer. >> >> It looks like the passed in if_softc is pointing to a struct ifvlan >> instead of the expected struct ieee80211_vap >> >> Looking at vlan_output(), I wonder if the parents ifnet context should be >> used when calling if_output()? something like: >> >> diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c >> index 2bb5284c2129..5fbd7a79dccc 100644 >> --- a/sys/net/if_vlan.c >> +++ b/sys/net/if_vlan.c >> @@ -1318,7 +1318,7 @@ vlan_output(struct ifnet *ifp, struct mbuf *m, >> const struct sockaddr *dst, >> ifv = p->if_softc; >> } while (p->if_type == IFT_L2VLAN); >> >> - return p->if_output(ifp, m, dst, ro); >> + return ((*p->if_output)(p, m, dst, ro)); >> > > No. Those two are the same thing. > > Warner > > } >> >> #ifdef ALTQ >> >> >> On Sat, Apr 23, 2022 at 1:12 PM Eugene Grosbein <eugen@grosbein.net> >> wrote: >> >>> 24.04.2022 3:28, Marek Zarychta wrote: >>> >>> > W dniu 23.04.2022 o 22:11, Craig Leres pisze: >>> >> >>> >> On 4/23/22 11:12, Craig Leres wrote: >>> >>> I am able to reproduce the crash with 13.1-RC4. >>> >> >>> >> I'm also able to reproduce the crash on 12.3-RELEASE-p5. It seems >>> wlan0 is part of the recipe, I tried vlans_em0="vlan0" first but was not >>> able to induce a crash. >>> >> >>> >> Craig >>> >> >>> > >>> > I am curious what is this WiFi hardware that supports 802.1q tagging >>> over the air? Could you please reveal this? >>> > >>> > That's rather not a bug when you are shooting yourself in the foot. >>> >>> Kernel panic due to ifconfig command is always a bug. >>> >>> >>> >>> --0000000000002094fe05dd674e87 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div>What do you mean when you say they are the same thing= ?</div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail= _attr">On Sun, Apr 24, 2022 at 5:35 AM Warner Losh <<a href=3D"mailto:im= p@bsdimp.com" target=3D"_blank">imp@bsdimp.com</a>> wrote:<br></div><blo= ckquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left= :1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"auto"><div><br><b= r><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Sun, = Apr 24, 2022, 1:03 AM Rob Wing <<a href=3D"mailto:rob.fx907@gmail.com" t= arget=3D"_blank">rob.fx907@gmail.com</a>> wrote:<br></div><blockquote cl= ass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid= rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>From what I can t= ell, the vlan driver is calling ieee80211_output() with the wrong ifnet con= text and dereferencing a bad pointer. <br></div><div><br></div><div>It look= s like the passed in if_softc is pointing to a struct ifvlan instead of the= expected struct ieee80211_vap</div><div><br></div><div>Looking at vlan_out= put(), I wonder if the parents ifnet context should be used when calling if= _output()? something like:</div><div><br></div><div>diff --git a/sys/net/if= _vlan.c b/sys/net/if_vlan.c<br>index 2bb5284c2129..5fbd7a79dccc 100644<br>-= -- a/sys/net/if_vlan.c<br>+++ b/sys/net/if_vlan.c<br>@@ -1318,7 +1318,7 @@ = vlan_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,<= br>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 ifv =3D p->if= _softc;<br>=C2=A0 =C2=A0 =C2=A0 =C2=A0 } while (p->if_type =3D=3D IFT_L2= VLAN);<br><br>- =C2=A0 =C2=A0 =C2=A0 return p->if_output(ifp, m, dst, ro= );<br>+ =C2=A0 =C2=A0 =C2=A0 return ((*p->if_output)(p, m, dst, ro));<br= ></div></div></blockquote></div></div><div dir=3D"auto"><br></div><div dir= =3D"auto">No. Those two are the same thing.</div><div dir=3D"auto"><br></di= v><div dir=3D"auto">Warner=C2=A0</div><div dir=3D"auto"><br></div><div dir= =3D"auto"><div class=3D"gmail_quote"><blockquote class=3D"gmail_quote" styl= e=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);paddin= g-left:1ex"><div dir=3D"ltr"><div>=C2=A0}<br><br>=C2=A0#ifdef ALTQ</div><di= v><br></div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"= gmail_attr">On Sat, Apr 23, 2022 at 1:12 PM Eugene Grosbein <<a href=3D"= mailto:eugen@grosbein.net" rel=3D"noreferrer" target=3D"_blank">eugen@grosb= ein.net</a>> wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"= margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-lef= t:1ex">24.04.2022 3:28, Marek Zarychta wrote:<br> <br> > W dniu 23.04.2022 o 22:11, Craig Leres pisze:<br> >><br> >> On 4/23/22 11:12, Craig Leres wrote:<br> >>> I am able to reproduce the crash with 13.1-RC4.<br> >><br> >> I'm also able to reproduce the crash on 12.3-RELEASE-p5. It se= ems wlan0 is part of the recipe, I tried vlans_em0=3D"vlan0" firs= t but was not able to induce a crash.<br> >><br> >>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Craig<br> >><br> > <br> > I am curious what is this WiFi hardware that supports 802.1q tagging o= ver the air? Could you please reveal this?<br> > <br> > That's rather not a bug when you are shooting yourself in the foot= .<br> <br> Kernel panic due to ifconfig command is always a bug.<br> <br> <br> <br> </blockquote></div> </blockquote></div></div></div> </blockquote></div> --0000000000002094fe05dd674e87--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAF3%2Bn_c_3bF4aaBVsLOSJ8GhKmcQjujAC=gAvjjDhDHT%2BmzN8A>