diff options
| author | Zhengchao Shao <shaozhengchao@huawei.com> | 2022-07-15 19:55:59 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-07-19 09:50:54 -0700 |
| commit | fd1894224407c484f652ad456e1ce423e89bb3eb (patch) | |
| tree | 9980e1d31ad073231806f842bea8c26e819e7e58 /include/linux/skbuff.h | |
| parent | 92f619735b7c4269fc6349a7ec13f09ffb558f77 (diff) | |
bpf: Don't redirect packets with invalid pkt_len
Syzbot found an issue [1]: fq_codel_drop() try to drop a flow whitout any
skbs, that is, the flow->head is null.
The root cause, as the [2] says, is because that bpf_prog_test_run_skb()
run a bpf prog which redirects empty skbs.
So we should determine whether the length of the packet modified by bpf
prog or others like bpf_prog_test is valid before forwarding it directly.
LINK: [1] https://syzkaller.appspot.com/bug?id=0b84da80c2917757915afa89f7738a9d16ec96c5
LINK: [2] https://www.spinics.net/lists/netdev/msg777503.html
Reported-by: syzbot+7a12909485b94426aceb@syzkaller.appspotmail.com
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220715115559.139691-1-shaozhengchao@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index f6a27ab19202..82e8368ba6e6 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2459,6 +2459,14 @@ static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) #endif /* NET_SKBUFF_DATA_USES_OFFSET */ +static inline void skb_assert_len(struct sk_buff *skb) +{ +#ifdef CONFIG_DEBUG_NET + if (WARN_ONCE(!skb->len, "%s\n", __func__)) + DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); +#endif /* CONFIG_DEBUG_NET */ +} + /* * Add data to an sk_buff */ |