From c4779cdd6abd6c087c1667dac92f5ec6b619e0d6 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 4 Feb 2025 11:43:43 +0100 Subject: [PATCH] dropped queue-5.10/udp-deal-with-race-between-udp-socket-address-change.patch broke the build AND was not in newer stable releases. --- queue-5.10/series | 1 - ...ce-between-udp-socket-address-change.patch | 301 ------------------ 2 files changed, 302 deletions(-) delete mode 100644 queue-5.10/udp-deal-with-race-between-udp-socket-address-change.patch diff --git a/queue-5.10/series b/queue-5.10/series index b5164f7de1..9cd77659e8 100644 --- a/queue-5.10/series +++ b/queue-5.10/series @@ -29,7 +29,6 @@ cpupower-fix-tsc-mhz-calculation.patch leds-netxbig-fix-an-of-node-reference-leak-in-netxbi.patch cpufreq-schedutil-simplify-sugov_update_next_freq.patch cpufreq-schedutil-fix-superfluous-updates-caused-by-.patch -udp-deal-with-race-between-udp-socket-address-change.patch clk-imx8mp-fix-clkout1-2-support.patch team-prevent-adding-a-device-which-is-already-a-team.patch regulator-of-implement-the-unwind-path-of-of_regulat.patch diff --git a/queue-5.10/udp-deal-with-race-between-udp-socket-address-change.patch b/queue-5.10/udp-deal-with-race-between-udp-socket-address-change.patch deleted file mode 100644 index 87c6a8c94e..0000000000 --- a/queue-5.10/udp-deal-with-race-between-udp-socket-address-change.patch +++ /dev/null @@ -1,301 +0,0 @@ -From e27cd5cf7f24ac02a5c48b834440c0618e75b6eb Mon Sep 17 00:00:00 2001 -From: Sasha Levin -Date: Wed, 18 Dec 2024 17:21:16 +0100 -Subject: udp: Deal with race between UDP socket address change and rehash - -From: Stefano Brivio - -[ Upstream commit a502ea6fa94b1f7be72a24bcf9e3f5f6b7e6e90c ] - -If a UDP socket changes its local address while it's receiving -datagrams, as a result of connect(), there is a period during which -a lookup operation might fail to find it, after the address is changed -but before the secondary hash (port and address) and the four-tuple -hash (local and remote ports and addresses) are updated. - -Secondary hash chains were introduced by commit 30fff9231fad ("udp: -bind() optimisation") and, as a result, a rehash operation became -needed to make a bound socket reachable again after a connect(). - -This operation was introduced by commit 719f835853a9 ("udp: add -rehash on connect()") which isn't however a complete fix: the -socket will be found once the rehashing completes, but not while -it's pending. - -This is noticeable with a socat(1) server in UDP4-LISTEN mode, and a -client sending datagrams to it. After the server receives the first -datagram (cf. _xioopen_ipdgram_listen()), it issues a connect() to -the address of the sender, in order to set up a directed flow. - -Now, if the client, running on a different CPU thread, happens to -send a (subsequent) datagram while the server's socket changes its -address, but is not rehashed yet, this will result in a failed -lookup and a port unreachable error delivered to the client, as -apparent from the following reproducer: - - LEN=$(($(cat /proc/sys/net/core/wmem_default) / 4)) - dd if=/dev/urandom bs=1 count=${LEN} of=tmp.in - - while :; do - taskset -c 1 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc & - sleep 0.1 || sleep 1 - taskset -c 2 socat OPEN:tmp.in UDP4:localhost:1337,shut-null - wait - done - -where the client will eventually get ECONNREFUSED on a write() -(typically the second or third one of a given iteration): - - 2024/11/13 21:28:23 socat[46901] E write(6, 0x556db2e3c000, 8192): Connection refused - -This issue was first observed as a seldom failure in Podman's tests -checking UDP functionality while using pasta(1) to connect the -container's network namespace, which leads us to a reproducer with -the lookup error resulting in an ICMP packet on a tap device: - - LOCAL_ADDR="$(ip -j -4 addr show|jq -rM '.[] | .addr_info[0] | select(.scope == "global").local')" - - while :; do - ./pasta --config-net -p pasta.pcap -u 1337 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc & - sleep 0.2 || sleep 1 - socat OPEN:tmp.in UDP4:${LOCAL_ADDR}:1337,shut-null - wait - cmp tmp.in tmp.out - done - -Once this fails: - - tmp.in tmp.out differ: char 8193, line 29 - -we can finally have a look at what's going on: - - $ tshark -r pasta.pcap - 1 0.000000 :: ? ff02::16 ICMPv6 110 Multicast Listener Report Message v2 - 2 0.168690 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 - 3 0.168767 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 - 4 0.168806 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 - 5 0.168827 c6:47:05:8d:dc:04 ? Broadcast ARP 42 Who has 88.198.0.161? Tell 88.198.0.164 - 6 0.168851 9a:55:9a:55:9a:55 ? c6:47:05:8d:dc:04 ARP 42 88.198.0.161 is at 9a:55:9a:55:9a:55 - 7 0.168875 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 - 8 0.168896 88.198.0.164 ? 88.198.0.161 ICMP 590 Destination unreachable (Port unreachable) - 9 0.168926 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 - 10 0.168959 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 - 11 0.168989 88.198.0.161 ? 88.198.0.164 UDP 4138 60260 ? 1337 Len=4096 - 12 0.169010 88.198.0.161 ? 88.198.0.164 UDP 42 60260 ? 1337 Len=0 - -On the third datagram received, the network namespace of the container -initiates an ARP lookup to deliver the ICMP message. - -In another variant of this reproducer, starting the client with: - - strace -f pasta --config-net -u 1337 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc 2>strace.log & - -and connecting to the socat server using a loopback address: - - socat OPEN:tmp.in UDP4:localhost:1337,shut-null - -we can more clearly observe a sendmmsg() call failing after the -first datagram is delivered: - - [pid 278012] connect(173, 0x7fff96c95fc0, 16) = 0 - [...] - [pid 278012] recvmmsg(173, 0x7fff96c96020, 1024, MSG_DONTWAIT, NULL) = -1 EAGAIN (Resource temporarily unavailable) - [pid 278012] sendmmsg(173, 0x561c5ad0a720, 1, MSG_NOSIGNAL) = 1 - [...] - [pid 278012] sendmmsg(173, 0x561c5ad0a720, 1, MSG_NOSIGNAL) = -1 ECONNREFUSED (Connection refused) - -and, somewhat confusingly, after a connect() on the same socket -succeeded. - -Until commit 4cdeeee9252a ("net: udp: prefer listeners bound to an -address"), the race between receive address change and lookup didn't -actually cause visible issues, because, once the lookup based on the -secondary hash chain failed, we would still attempt a lookup based on -the primary hash (destination port only), and find the socket with the -outdated secondary hash. - -That change, however, dropped port-only lookups altogether, as side -effect, making the race visible. - -To fix this, while avoiding the need to make address changes and -rehash atomic against lookups, reintroduce primary hash lookups as -fallback, if lookups based on four-tuple and secondary hashes fail. - -To this end, introduce a simplified lookup implementation, which -doesn't take care of SO_REUSEPORT groups: if we have one, there are -multiple sockets that would match the four-tuple or secondary hash, -meaning that we can't run into this race at all. - -v2: - - instead of synchronising lookup operations against address change - plus rehash, reintroduce a simplified version of the original - primary hash lookup as fallback - -v1: - - fix build with CONFIG_IPV6=n: add ifdef around sk_v6_rcv_saddr - usage (Kuniyuki Iwashima) - - directly use sk_rcv_saddr for IPv4 receive addresses instead of - fetching inet_rcv_saddr (Kuniyuki Iwashima) - - move inet_update_saddr() to inet_hashtables.h and use that - to set IPv4/IPv6 addresses as suitable (Kuniyuki Iwashima) - - rebase onto net-next, update commit message accordingly - -Reported-by: Ed Santiago -Link: https://github.com/containers/podman/issues/24147 -Analysed-by: David Gibson -Fixes: 30fff9231fad ("udp: bind() optimisation") -Signed-off-by: Stefano Brivio -Reviewed-by: Eric Dumazet -Reviewed-by: Willem de Bruijn -Signed-off-by: David S. Miller -Signed-off-by: Sasha Levin ---- - net/ipv4/udp.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++ - net/ipv6/udp.c | 50 ++++++++++++++++++++++++++++++++++++++++++++ - 2 files changed, 106 insertions(+) - -diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c -index 6ad25dc9710c1..0f835abe7c9e9 100644 ---- a/net/ipv4/udp.c -+++ b/net/ipv4/udp.c -@@ -412,6 +412,49 @@ u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport, - udp_ehash_secret + net_hash_mix(net)); - } - -+/** -+ * udp4_lib_lookup1() - Simplified lookup using primary hash (destination port) -+ * @net: Network namespace -+ * @saddr: Source address, network order -+ * @sport: Source port, network order -+ * @daddr: Destination address, network order -+ * @hnum: Destination port, host order -+ * @dif: Destination interface index -+ * @sdif: Destination bridge port index, if relevant -+ * @udptable: Set of UDP hash tables -+ * -+ * Simplified lookup to be used as fallback if no sockets are found due to a -+ * potential race between (receive) address change, and lookup happening before -+ * the rehash operation. This function ignores SO_REUSEPORT groups while scoring -+ * result sockets, because if we have one, we don't need the fallback at all. -+ * -+ * Called under rcu_read_lock(). -+ * -+ * Return: socket with highest matching score if any, NULL if none -+ */ -+static struct sock *udp4_lib_lookup1(const struct net *net, -+ __be32 saddr, __be16 sport, -+ __be32 daddr, unsigned int hnum, -+ int dif, int sdif, -+ const struct udp_table *udptable) -+{ -+ unsigned int slot = udp_hashfn(net, hnum, udptable->mask); -+ struct udp_hslot *hslot = &udptable->hash[slot]; -+ struct sock *sk, *result = NULL; -+ int score, badness = 0; -+ -+ sk_for_each_rcu(sk, &hslot->head) { -+ score = compute_score(sk, net, -+ saddr, sport, daddr, hnum, dif, sdif); -+ if (score > badness) { -+ result = sk; -+ badness = score; -+ } -+ } -+ -+ return result; -+} -+ - /* called with rcu_read_lock() */ - static struct sock *udp4_lib_lookup2(struct net *net, - __be32 saddr, __be16 sport, -@@ -539,6 +582,19 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, - result = udp4_lib_lookup2(net, saddr, sport, - htonl(INADDR_ANY), hnum, dif, sdif, - hslot2, skb); -+ if (!IS_ERR_OR_NULL(result)) -+ goto done; -+ -+ /* Primary hash (destination port) lookup as fallback for this race: -+ * 1. __ip4_datagram_connect() sets sk_rcv_saddr -+ * 2. lookup (this function): new sk_rcv_saddr, hashes not updated yet -+ * 3. rehash operation updating _secondary and four-tuple_ hashes -+ * The primary hash doesn't need an update after 1., so, thanks to this -+ * further step, 1. and 3. don't need to be atomic against the lookup. -+ */ -+ result = udp4_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif, -+ udptable); -+ - done: - if (IS_ERR(result)) - return NULL; -diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c -index 203a6d64d7e99..9f5aaf90ce905 100644 ---- a/net/ipv6/udp.c -+++ b/net/ipv6/udp.c -@@ -156,6 +156,49 @@ static int compute_score(struct sock *sk, struct net *net, - return score; - } - -+/** -+ * udp6_lib_lookup1() - Simplified lookup using primary hash (destination port) -+ * @net: Network namespace -+ * @saddr: Source address, network order -+ * @sport: Source port, network order -+ * @daddr: Destination address, network order -+ * @hnum: Destination port, host order -+ * @dif: Destination interface index -+ * @sdif: Destination bridge port index, if relevant -+ * @udptable: Set of UDP hash tables -+ * -+ * Simplified lookup to be used as fallback if no sockets are found due to a -+ * potential race between (receive) address change, and lookup happening before -+ * the rehash operation. This function ignores SO_REUSEPORT groups while scoring -+ * result sockets, because if we have one, we don't need the fallback at all. -+ * -+ * Called under rcu_read_lock(). -+ * -+ * Return: socket with highest matching score if any, NULL if none -+ */ -+static struct sock *udp6_lib_lookup1(const struct net *net, -+ const struct in6_addr *saddr, __be16 sport, -+ const struct in6_addr *daddr, -+ unsigned int hnum, int dif, int sdif, -+ const struct udp_table *udptable) -+{ -+ unsigned int slot = udp_hashfn(net, hnum, udptable->mask); -+ struct udp_hslot *hslot = &udptable->hash[slot]; -+ struct sock *sk, *result = NULL; -+ int score, badness = 0; -+ -+ sk_for_each_rcu(sk, &hslot->head) { -+ score = compute_score(sk, net, -+ saddr, sport, daddr, hnum, dif, sdif); -+ if (score > badness) { -+ result = sk; -+ badness = score; -+ } -+ } -+ -+ return result; -+} -+ - /* called with rcu_read_lock() */ - static struct sock *udp6_lib_lookup2(struct net *net, - const struct in6_addr *saddr, __be16 sport, -@@ -284,6 +327,13 @@ struct sock *__udp6_lib_lookup(struct net *net, - result = udp6_lib_lookup2(net, saddr, sport, - &in6addr_any, hnum, dif, sdif, - hslot2, skb); -+ if (!IS_ERR_OR_NULL(result)) -+ goto done; -+ -+ /* Cover address change/lookup/rehash race: see __udp4_lib_lookup() */ -+ result = udp6_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif, -+ udptable); -+ - done: - if (IS_ERR(result)) - return NULL; --- -2.39.5 - -- 2.47.3