| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.18 064/197] tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattach | Date | Thu, 13 Sep 2018 15:30:13 +0200 |
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4.18-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Borkmann <daniel@iogearbox.net>
[ Upstream commit 90545cdc3f2b2ea700e24335610cd181e73756da ]
I found that in BPF sockmap programs once we either delete a socket from the map or we updated a map slot and the old socket was purged from the map that these socket can never get reattached into a map even though their related psock has been dropped entirely at that point.
Reason is that tcp_cleanup_ulp() leaves the old icsk->icsk_ulp_ops intact, so that on the next tcp_set_ulp_id() the kernel returns an -EEXIST thinking there is still some active ULP attached.
BPF sockmap is the only one that has this issue as the other user, kTLS, only calls tcp_cleanup_ulp() from tcp_v4_destroy_sock() whereas sockmap semantics allow dropping the socket from the map with all related psock state being cleaned up.
Fixes: 1aa12bdf1bfb ("bpf: sockmap, add sock close() hook to remove socks") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv4/tcp_ulp.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/ipv4/tcp_ulp.c +++ b/net/ipv4/tcp_ulp.c @@ -129,6 +129,8 @@ void tcp_cleanup_ulp(struct sock *sk) if (icsk->icsk_ulp_ops->release) icsk->icsk_ulp_ops->release(sk); module_put(icsk->icsk_ulp_ops->owner); + + icsk->icsk_ulp_ops = NULL; } /* Change upper layer protocol for socket */
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