4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit f4924f24da8c7ef64195096817f3cde324091d97 ] In sock_setsockopt() (net/core/sock.h), when SO_MARK option is used to change sk_mark, sk_dst_reset(sk) is called. The same should be done in bpf_setsockopt(). Fixes: 8c4b4c7e9ff0 ("bpf: Add setsockopt helper function to bpf") Reported-by: Maciej Żenczykowski <maze@xxxxxxxxxx> Signed-off-by: Peter Oskolkov <posk@xxxxxxxxxx> Acked-by: Martin KaFai Lau <kafai@xxxxxx> Reviewed-by: Maciej Żenczykowski <maze@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/core/filter.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 3400c7abda135..fb0080e84bd43 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3930,7 +3930,10 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, sk->sk_rcvlowat = val ? : 1; break; case SO_MARK: - sk->sk_mark = val; + if (sk->sk_mark != val) { + sk->sk_mark = val; + sk_dst_reset(sk); + } break; default: ret = -EINVAL; -- 2.19.1