On Fri, Sep 04, 2020 at 02:22:46PM +0000, Nuernberger, Stefan wrote: > On Fri, 2020-09-04 at 16:16 +0200, Greg Kroah-Hartman wrote: > > On Fri, Sep 04, 2020 at 03:30:52PM +0200, Stefan Nuernberger wrote: > > > > > > From: Or Cohen <orcohen@xxxxxxxxxxxxxxxxxxxx> > > > > > > Using tp_reserve to calculate netoff can overflow as > > > tp_reserve is unsigned int and netoff is unsigned short. > > > > > > This may lead to macoff receving a smaller value then > > > sizeof(struct virtio_net_hdr), and if po->has_vnet_hdr > > > is set, an out-of-bounds write will occur when > > > calling virtio_net_hdr_from_skb. > > > > > > The bug is fixed by converting netoff to unsigned int > > > and checking if it exceeds USHRT_MAX. > > > > > > This addresses CVE-2020-14386 > > > > > > Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt") > > > Signed-off-by: Or Cohen <orcohen@xxxxxxxxxxxxxxxxxxxx> > > > Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> > > > > > > [ snu: backported to 4.9, changed tp_drops counting/locking ] > > > > > > Signed-off-by: Stefan Nuernberger <snu@xxxxxxxxxx> > > > CC: David Woodhouse <dwmw@xxxxxxxxxxxx> > > > CC: Amit Shah <aams@xxxxxxxxxx> > > > CC: stable@xxxxxxxxxxxxxxx > > > --- > > > net/packet/af_packet.c | 9 ++++++++- > > > 1 file changed, 8 insertions(+), 1 deletion(-) > > What is the git commit id of this patch in Linus's tree? > > > > Sorry, this isn't merged on Linus' tree yet. It's a heads up that the > backport isn't straightforward. Ok, please be more specific about this when sending patches out... greg k-h