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| author | Zhengchao Shao <shaozhengchao@huawei.com> | 2022-07-15 19:55:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 10:30:07 +0200 |
| commit | a75987714bd2d8e59840667a28e15c1fa5c47554 (patch) | |
| tree | 8239706ccc08b9ef0b110c80341beec3d5e47b55 /include | |
| parent | e4ae97295984ff1b9b340ed18ae1b066f36b7835 (diff) | |
| download | linux-a75987714bd2d8e59840667a28e15c1fa5c47554.tar.gz linux-a75987714bd2d8e59840667a28e15c1fa5c47554.tar.bz2 linux-a75987714bd2d8e59840667a28e15c1fa5c47554.zip | |
bpf: Don't redirect packets with invalid pkt_len
commit fd1894224407c484f652ad456e1ce423e89bb3eb upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -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 cbd719e5329a..ae598ed86b50 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2328,6 +2328,14 @@ 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 */ |