bpf, sockmap: Do not ignore orig_len parameter
authorEric Dumazet <edumazet@google.com>
Wed, 2 Mar 2022 16:17:22 +0000 (08:17 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 8 Mar 2022 18:12:44 +0000 (19:12 +0100)
commit00c74b587197b0c503a8b1057a464ad13462444f
tree0f2fc237590cd7ff5f931e46935e5a959ba46e70
parentbd61f192a339b1095dfd6d56073a5265934c2979
bpf, sockmap: Do not ignore orig_len parameter

commit 60ce37b03917e593d8e5d8bcc7ec820773daf81d upstream.

Currently, sk_psock_verdict_recv() returns skb->len

This is problematic because tcp_read_sock() might have
passed orig_len < skb->len, due to the presence of TCP urgent data.

This causes an infinite loop from tcp_read_sock()

Followup patch will make tcp_read_sock() more robust vs bad actors.

Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Tested-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220302161723.3910001-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/core/skmsg.c