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| author | Zhengchao Shao <shaozhengchao@huawei.com> | 2022-07-15 14:55:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 11:28:56 +0300 |
| commit | 6204bf78b2a903b96ba43afff6abc0b04d6e0462 (patch) | |
| tree | ad973c001cf04542c2fa2317cf43720d10d0df46 /net/core | |
| parent | dbd8c8fc60480e3faa3ae7e27ebe03371ecd1b77 (diff) | |
| download | linux-6204bf78b2a903b96ba43afff6abc0b04d6e0462.tar.xz | |
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 'net/core')
| -rw-r--r-- | net/core/dev.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 8355cc5e11a9..34b5aab42b91 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4097,6 +4097,7 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) bool again = false; skb_reset_mac_header(skb); + skb_assert_len(skb); if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP)) __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED); |