From: Dmitry Vyukov <dvyu...@gmail.com> Date: Fri, 25 Jan 2019 11:46:40 +0100
> From: Bernard Pidoux <f6...@free.fr> > > When an internally generated frame is handled by rose_xmit(), > rose_route_frame() is called: > > if (!rose_route_frame(skb, NULL)) { > dev_kfree_skb(skb); > stats->tx_errors++; > return NETDEV_TX_OK; > } > > We have the same code sequence in Net/Rom where an internally generated > frame is handled by nr_xmit() calling nr_route_frame(skb, NULL). > However, in this function NULL argument is tested while it is not in > rose_route_frame(). > Then kernel panic occurs later on when calling ax25cmp() with a NULL > ax25_cb argument as reported many times and recently with syzbot. > > We need to test if ax25 is NULL before using it. > > Testing: > Built kernel with CONFIG_ROSE=y. > > Signed-off-by: Bernard Pidoux <f6...@free.fr> > Acked-by: Dmitry Vyukov <dvyu...@google.com> > Reported-by: syzbot+1a2c456a1ea08fa5b...@syzkaller.appspotmail.com Applied and queued up for -stable, thanks.