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[73.158.218.242]) by smtp.gmail.com with UTF8SMTPSA id d9443c01a7336-241e8975c94sm303016765ad.93.2025.08.12.08.52.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Aug 2025 08:52:50 -0700 (PDT) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ayush.sawal@chelsio.com, andrew+netdev@lunn.ch, gregkh@linuxfoundation.org, horms@kernel.org, dsahern@kernel.org, pablo@netfilter.org, kadlec@netfilter.org, steffen.klassert@secunet.com, sdf@fomichev.me, mhal@rbox.co, abhishektamboli9@gmail.com, linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, herbert@gondor.apana.org.au Subject: [PATCH net-next 4/7] net: Switch to skb_dst_reset/skb_dst_restore for ip_route_input callers Date: Tue, 12 Aug 2025 08:52:42 -0700 Message-ID: <20250812155245.507012-5-sdf@fomichev.me> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250812155245.507012-1-sdf@fomichev.me> References: <20250812155245.507012-1-sdf@fomichev.me> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set. skb_dst_reset is added to reset existing entry without doing refcnt. skb_dst_restore should be used to restore the previous entry. Convert icmp_route_lookup and ip_options_rcv_srr to these helpers. Add extra call to skb_dst_drop to icmp_route_lookup to clear the ip_route_input entry. Signed-off-by: Stanislav Fomichev --- net/ipv4/icmp.c | 7 ++++--- net/ipv4/ip_options.c | 5 ++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 2ffe73ea644f..93a166a7ec8d 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -544,14 +544,15 @@ static struct rtable *icmp_route_lookup(struct net *n= et, struct flowi4 *fl4, goto relookup_failed; } /* Ugh! */ - orefdst =3D skb_in->_skb_refdst; /* save old refdst */ - skb_dst_set(skb_in, NULL); + orefdst =3D skb_dst_reset(skb_in); err =3D ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr, dscp, rt2->dst.dev) ? -EINVAL : 0; =20 dst_release(&rt2->dst); rt2 =3D skb_rtable(skb_in); - skb_in->_skb_refdst =3D orefdst; /* restore old refdst */ + /* steal dst entry from skb_in, don't drop refcnt */ + skb_dst_reset(skb_in); + skb_dst_restore(skb_in, orefdst); } =20 if (err) diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index e3321932bec0..95f113dc37d8 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -615,14 +615,13 @@ int ip_options_rcv_srr(struct sk_buff *skb, struct ne= t_device *dev) } memcpy(&nexthop, &optptr[srrptr-1], 4); =20 - orefdst =3D skb->_skb_refdst; - skb_dst_set(skb, NULL); + orefdst =3D skb_dst_reset(skb); err =3D ip_route_input(skb, nexthop, iph->saddr, ip4h_dscp(iph), dev) ? -EINVAL : 0; rt2 =3D skb_rtable(skb); if (err || (rt2->rt_type !=3D RTN_UNICAST && rt2->rt_type !=3D RTN_LOCAL= )) { skb_dst_drop(skb); - skb->_skb_refdst =3D orefdst; + skb_dst_restore(skb, orefdst); return -EINVAL; } refdst_drop(orefdst); --=20 2.50.1