Re: Re: KASAN: slab-out-of-bounds Read in bpf_skb_vlan_push

syzbot
2018-06-13T18:13:28Z

> On 06/13/2018 06:17 PM, syzbot wrote:
>> Hello,

>> syzbot found the following crash on:

>> HEAD commit:    75d4e704fa8d netdev-FAQ: clarify DaveM's position for
>> stab..
>> git tree:       bpf-next
>> console output: https://syzkaller.appspot.com/x/log.txt?x=1754783f800000
>> kernel config:
>> https://syzkaller.appspot.com/x/.config?x=a601a80fec461d44
>> dashboard link:
>> https://syzkaller.appspot.com/bug?extid=76de61614cb1abdd73fc
>> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
>> syzkaller
>> repro:https://syzkaller.appspot.com/x/repro.syz?x=12c1e1bf800000

>> IMPORTANT: if you fix the bug, please add the following tag to the
>> commit:
>> Reported-by: syzbot+76de61614cb1abdd73fc@syzkaller.appspotmail.com

>> IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
>> IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
>> 8021q: adding VLAN 0 to HW filter on device team0
>> 8021q: adding VLAN 0 to HW filter on device team0
>> ==================================================================
>> BUG: KASAN: slab-out-of-bounds in skb_at_tc_ingress
>> include/net/sch_generic.h:535 [inline]
>> BUG: KASAN: slab-out-of-bounds in bpf_push_mac_rcsum
>> net/core/filter.c:1625 [inline]
>> BUG: KASAN: slab-out-of-bounds in ____bpf_skb_vlan_push
>> net/core/filter.c:2446 [inline]
>> BUG: KASAN: slab-out-of-bounds in bpf_skb_vlan_push+0x6b7/0x720
>> net/core/filter.c:2437
>> Read of size 5 at addr ffff8801b77347d0 by task syz-executor6/6529

> Should be fixed already by:

>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=58990d1ff3f7896ee341030e9a7c2e4002570683

> #syz test:
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

want 2 args (repo, branch), got 1