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| author | Florian Westphal <fw@strlen.de> | 2022-07-26 12:42:06 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-03 12:03:53 +0200 |
| commit | 91c11008aab0282957b8b8ccb0707d90e74cc3b9 (patch) | |
| tree | 81a10bb1b744d36eda65508b22cd638a159e87e2 | |
| parent | be5cd347ba22fbeacd26e35d8d8386b8e95bfe0f (diff) | |
| download | linux-91c11008aab0282957b8b8ccb0707d90e74cc3b9.tar.gz linux-91c11008aab0282957b8b8ccb0707d90e74cc3b9.tar.bz2 linux-91c11008aab0282957b8b8ccb0707d90e74cc3b9.zip | |
netfilter: nf_queue: do not allow packet truncation below transport header offset
[ Upstream commit 99a63d36cb3ed5ca3aa6fcb64cffbeaf3b0fb164 ]
Domingo Dirutigliano and Nicola Guerrera report kernel panic when
sending nf_queue verdict with 1-byte nfta_payload attribute.
The IP/IPv6 stack pulls the IP(v6) header from the packet after the
input hook.
If user truncates the packet below the header size, this skb_pull() will
result in a malformed skb (skb->len < 0).
Fixes: 7af4cc3fa158 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink")
Reported-by: Domingo Dirutigliano <pwnzer0tt1@proton.me>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/netfilter/nfnetlink_queue.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 8787d0613ad8..5329ebf19a18 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -836,11 +836,16 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) } static int -nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff) +nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff) { struct sk_buff *nskb; if (diff < 0) { + unsigned int min_len = skb_transport_offset(e->skb); + + if (data_len < min_len) + return -EINVAL; + if (pskb_trim(e->skb, data_len)) return -ENOMEM; } else if (diff > 0) { |