From: Phil Sutter Date: Tue, 19 Dec 2017 14:17:13 +0000 (+0100) Subject: ipv4: fib: Fix metrics match when deleting a route X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=86deaaa0ca2b0657e1f72e1087153d4ff22a312b;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git ipv4: fib: Fix metrics match when deleting a route [ Upstream commit d03a45572efa068fa64db211d6d45222660e76c5 ] The recently added fib_metrics_match() causes a regression for routes with both RTAX_FEATURES and RTAX_CC_ALGO if the latter has TCP_CONG_NEEDS_ECN flag set: | # ip link add d0 type dummy | # ip link set d0 up | # ip route add 172.29.29.0/24 dev d0 features ecn congctl dctcp | # ip route del 172.29.29.0/24 dev d0 features ecn congctl dctcp | RTNETLINK answers: No such process During route insertion, fib_convert_metrics() detects that the given CC algo requires ECN and hence sets DST_FEATURE_ECN_CA bit in RTAX_FEATURES. During route deletion though, fib_metrics_match() compares stored RTAX_FEATURES value with that from userspace (which obviously has no knowledge about DST_FEATURE_ECN_CA) and fails. Fixes: 5f9ae3d9e7e4a ("ipv4: do metrics match when looking up and deleting a route") Signed-off-by: Phil Sutter Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 01ed22139ac2..aff3751df950 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -706,7 +706,7 @@ bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { int type = nla_type(nla); - u32 val; + u32 fi_val, val; if (!type) continue; @@ -723,7 +723,11 @@ bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) val = nla_get_u32(nla); } - if (fi->fib_metrics->metrics[type - 1] != val) + fi_val = fi->fib_metrics->metrics[type - 1]; + if (type == RTAX_FEATURES) + fi_val &= ~DST_FEATURE_ECN_CA; + + if (fi_val != val) return false; }