This series includes 6 types of fixes:
- Patch 1 fixes v4 mapped in v6 addresses support for the userspace PM, when asking to delete a subflow. It was done everywhere else, but not there. Patch 2 validates the modification, thanks to a subtest in mptcp_join.sh. These patches can be backported up to v5.19.
- Patch 3 is a small fix for a recent bug-fix patch, just to avoid printing an irrelevant warning (pr_warn()) once. It can be backported up to v5.6, alongside the bug-fix that has been introduced in the v6.8-rc5.
- Patches 4 to 6 are fixes for bugs found by Paolo while working on TCP_NOTSENT_LOWAT support for MPTCP. These fixes can improve the performances in some cases. Patches can be backported up to v5.6, v5.11 and v6.7 respectively.
- Patch 7 makes sure 'ss -M' is available when starting MPTCP Join selftest as it is required for some subtests since v5.18.
- Patch 8 fixes a possible double-free on socket dismantle. The issue always existed, but was unnoticed because it was not causing any problem so far. This fix can be backported up to v5.6.
- Patch 9 is a fix for a very recent patch causing lockdep warnings in subflow diag. The patch causing the regression -- which fixes another issue present since v5.7 -- should be part of the future v6.8-rc6. Patch 10 validates the modification, thanks to a new subtest in diag.sh.
Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- Davide Caratti (1): mptcp: fix double-free on socket dismantle
Geliang Tang (3): mptcp: map v4 address to v6 when destroying subflow selftests: mptcp: rm subflow with v4/v4mapped addr selftests: mptcp: join: add ss mptcp support check
Matthieu Baerts (NGI0) (1): mptcp: avoid printing warning once on client side
Paolo Abeni (5): mptcp: push at DSS boundaries mptcp: fix snd_wnd initialization for passive socket mptcp: fix potential wake-up event loss mptcp: fix possible deadlock in subflow diag selftests: mptcp: explicitly trigger the listener diag code-path
net/mptcp/diag.c | 3 ++ net/mptcp/options.c | 2 +- net/mptcp/pm_userspace.c | 10 +++++ net/mptcp/protocol.c | 52 ++++++++++++++++++++++++- net/mptcp/protocol.h | 21 +++++----- tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++- tools/testing/selftests/net/mptcp/mptcp_join.sh | 33 ++++++++++------ tools/testing/selftests/net/mptcp/mptcp_lib.sh | 4 +- 8 files changed, 128 insertions(+), 27 deletions(-) --- base-commit: b0b1210bc150fbd741b4b9fce8a24541306b40fc change-id: 20240223-upstream-net-20240223-misc-fixes-1630cd6b3b0a
Best regards,
From: Geliang Tang tanggeliang@kylinos.cn
Address family of server side mismatches with that of client side, like in "userspace pm add & remove address" test:
userspace_pm_add_addr $ns1 10.0.2.1 10 userspace_pm_rm_sf $ns1 "::ffff:10.0.2.1" $SUB_ESTABLISHED
That's because on the server side, the family is set to AF_INET6 and the v4 address is mapped in a v6 one.
This patch fixes this issue. In mptcp_pm_nl_subflow_destroy_doit(), before checking local address family with remote address family, map an IPv4 address to an IPv6 address if the pair is a v4-mapped address.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/387 Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment") Cc: stable@vger.kernel.org Signed-off-by: Geliang Tang tanggeliang@kylinos.cn Reviewed-by: Mat Martineau martineau@kernel.org Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm_userspace.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index d396a5973429..bc97cc30f013 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -495,6 +495,16 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info goto destroy_err; }
+#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (addr_l.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) { + ipv6_addr_set_v4mapped(addr_l.addr.s_addr, &addr_l.addr6); + addr_l.family = AF_INET6; + } + if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr6)) { + ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6); + addr_r.family = AF_INET6; + } +#endif if (addr_l.family != addr_r.family) { GENL_SET_ERR_MSG(info, "address families do not match"); err = -EINVAL;
From: Geliang Tang tanggeliang@kylinos.cn
Now both a v4 address and a v4-mapped address are supported when destroying a userspace pm subflow, this patch adds a second subflow to "userspace pm add & remove address" test, and two subflows could be removed two different ways, one with the v4mapped and one with v4.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/387 Fixes: 48d73f609dcc ("selftests: mptcp: update userspace pm addr tests") Cc: stable@vger.kernel.org Signed-off-by: Geliang Tang tanggeliang@kylinos.cn Reviewed-by: Mat Martineau martineau@kernel.org Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 28 ++++++++++++++----------- tools/testing/selftests/net/mptcp/mptcp_lib.sh | 4 ++-- 2 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index c07386e21e0a..e68b1bc2c2e4 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -3333,16 +3333,17 @@ userspace_pm_rm_sf() { local evts=$evts_ns1 local t=${3:-1} - local ip=4 + local ip local tk da dp sp local cnt
[ "$1" == "$ns2" ] && evts=$evts_ns2 - if mptcp_lib_is_v6 $2; then ip=6; fi + [ -n "$(mptcp_lib_evts_get_info "saddr4" "$evts" $t)" ] && ip=4 + [ -n "$(mptcp_lib_evts_get_info "saddr6" "$evts" $t)" ] && ip=6 tk=$(mptcp_lib_evts_get_info token "$evts") - da=$(mptcp_lib_evts_get_info "daddr$ip" "$evts" $t) - dp=$(mptcp_lib_evts_get_info dport "$evts" $t) - sp=$(mptcp_lib_evts_get_info sport "$evts" $t) + da=$(mptcp_lib_evts_get_info "daddr$ip" "$evts" $t $2) + dp=$(mptcp_lib_evts_get_info dport "$evts" $t $2) + sp=$(mptcp_lib_evts_get_info sport "$evts" $t $2)
cnt=$(rm_sf_count ${1}) ip netns exec $1 ./pm_nl_ctl dsf lip $2 lport $sp \ @@ -3429,20 +3430,23 @@ userspace_tests() if reset_with_events "userspace pm add & remove address" && continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then set_userspace_pm $ns1 - pm_nl_set_limits $ns2 1 1 + pm_nl_set_limits $ns2 2 2 speed=5 \ run_tests $ns1 $ns2 10.0.1.1 & local tests_pid=$! wait_mpj $ns1 userspace_pm_add_addr $ns1 10.0.2.1 10 - chk_join_nr 1 1 1 - chk_add_nr 1 1 - chk_mptcp_info subflows 1 subflows 1 - chk_subflows_total 2 2 - chk_mptcp_info add_addr_signal 1 add_addr_accepted 1 + userspace_pm_add_addr $ns1 10.0.3.1 20 + chk_join_nr 2 2 2 + chk_add_nr 2 2 + chk_mptcp_info subflows 2 subflows 2 + chk_subflows_total 3 3 + chk_mptcp_info add_addr_signal 2 add_addr_accepted 2 userspace_pm_rm_addr $ns1 10 userspace_pm_rm_sf $ns1 "::ffff:10.0.2.1" $SUB_ESTABLISHED - chk_rm_nr 1 1 invert + userspace_pm_rm_addr $ns1 20 + userspace_pm_rm_sf $ns1 10.0.3.1 $SUB_ESTABLISHED + chk_rm_nr 2 2 invert chk_mptcp_info subflows 0 subflows 0 chk_subflows_total 1 1 kill_events_pids diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh index 3a2abae5993e..3777d66fc56d 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh @@ -213,9 +213,9 @@ mptcp_lib_get_info_value() { grep "${2}" | sed -n 's/.*('"${1}"':)([0-9a-f:.]*).*$/\2/p;q' }
-# $1: info name ; $2: evts_ns ; $3: event type +# $1: info name ; $2: evts_ns ; [$3: event type; [$4: addr]] mptcp_lib_evts_get_info() { - mptcp_lib_get_info_value "${1}" "^type:${3:-1}," < "${2}" + grep "${4:-}" "${2}" | mptcp_lib_get_info_value "${1}" "^type:${3:-1}," }
# $1: PID
After the 'Fixes' commit mentioned below, the client side might print the following warning once when a subflow is fully established at the reception of any valid additional ack:
MPTCP: bogus mpc option on established client sk
That's a normal situation, and no warning should be printed for that. We can then skip the check when the label is used.
Fixes: e4a0fa47e816 ("mptcp: corner case locking for rx path fields initialization") Cc: stable@vger.kernel.org Suggested-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/options.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index e3e96a49f922..63fc0758c22d 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -981,10 +981,10 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, if (mp_opt->deny_join_id0) WRITE_ONCE(msk->pm.remote_deny_join_id0, true);
-set_fully_established: if (unlikely(!READ_ONCE(msk->pm.server_side))) pr_warn_once("bogus mpc option on established client sk");
+set_fully_established: mptcp_data_lock((struct sock *)msk); __mptcp_subflow_fully_established(msk, subflow, mp_opt); mptcp_data_unlock((struct sock *)msk);
From: Paolo Abeni pabeni@redhat.com
when inserting not contiguous data in the subflow write queue, the protocol creates a new skb and prevent the TCP stack from merging it later with already queued skbs by setting the EOR marker.
Still no push flag is explicitly set at the end of previous GSO packet, making the aggregation on the receiver side sub-optimal - and packetdrill self-tests less predictable.
Explicitly mark the end of not contiguous DSS with the push flag.
Fixes: 6d0060f600ad ("mptcp: Write MPTCP DSS headers to outgoing data packets") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 948606a537da..442fa7d9b57a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1260,6 +1260,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, mpext = mptcp_get_ext(skb); if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) { TCP_SKB_CB(skb)->eor = 1; + tcp_mark_push(tcp_sk(ssk), skb); goto alloc_skb; }
From: Paolo Abeni pabeni@redhat.com
Such value should be inherited from the first subflow, but passive sockets always used 'rsk_rcv_wnd'.
Fixes: 6f8a612a33e4 ("mptcp: keep track of advertised windows right edge") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/protocol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 442fa7d9b57a..2c8f931c6d5b 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3211,7 +3211,7 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk, msk->write_seq = subflow_req->idsn + 1; msk->snd_nxt = msk->write_seq; msk->snd_una = msk->write_seq; - msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd; + msk->wnd_end = msk->snd_nxt + tcp_sk(ssk)->snd_wnd; msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq; mptcp_init_sched(msk, mptcp_sk(sk)->sched);
Hi Jakub, Paolo, Stephen,
On 23/02/2024 5:14 pm, Matthieu Baerts (NGI0) wrote:
From: Paolo Abeni pabeni@redhat.com
Such value should be inherited from the first subflow, but passive sockets always used 'rsk_rcv_wnd'.
Fixes: 6f8a612a33e4 ("mptcp: keep track of advertised windows right edge") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org
net/mptcp/protocol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 442fa7d9b57a..2c8f931c6d5b 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3211,7 +3211,7 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk, msk->write_seq = subflow_req->idsn + 1; msk->snd_nxt = msk->write_seq; msk->snd_una = msk->write_seq;
- msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
- msk->wnd_end = msk->snd_nxt + tcp_sk(ssk)->snd_wnd;
Please note that this patch will conflict with the following commit from net-next:
3f83d8a77eee ("mptcp: fix more tx path fields initialization")
That's because this commit modifies the same line as the one modified here. We cannot avoid a conflict here. To fix it, please use 'WRITE_ONCE()' with the new line from -net:
WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);
A 3-way diff has been attached to this email.
msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq; mptcp_init_sched(msk, mptcp_sk(sk)->sched);
Cheers, Matt
From: Paolo Abeni pabeni@redhat.com
After the blamed commit below, the send buffer auto-tuning can happen after that the mptcp_propagate_sndbuf() completes - via the delegated action infrastructure.
We must check for write space even after such change or we risk missing the wake-up event.
Fixes: 8005184fd1ca ("mptcp: refactor sndbuf auto-tuning") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/protocol.h | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 631a7f445f34..07f6242afc1a 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -790,6 +790,16 @@ static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk) READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt); }
+static inline void mptcp_write_space(struct sock *sk) +{ + if (sk_stream_is_writeable(sk)) { + /* pairs with memory barrier in mptcp_poll */ + smp_mb(); + if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags)) + sk_stream_write_space(sk); + } +} + static inline void __mptcp_sync_sndbuf(struct sock *sk) { struct mptcp_subflow_context *subflow; @@ -808,6 +818,7 @@ static inline void __mptcp_sync_sndbuf(struct sock *sk)
/* the msk max wmem limit is <nr_subflows> * tcp wmem[2] */ WRITE_ONCE(sk->sk_sndbuf, new_sndbuf); + mptcp_write_space(sk); }
/* The called held both the msk socket and the subflow socket locks, @@ -838,16 +849,6 @@ static inline void mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk) local_bh_enable(); }
-static inline void mptcp_write_space(struct sock *sk) -{ - if (sk_stream_is_writeable(sk)) { - /* pairs with memory barrier in mptcp_poll */ - smp_mb(); - if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags)) - sk_stream_write_space(sk); - } -} - void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
#define MPTCP_TOKEN_MAX_RETRIES 4
From: Geliang Tang tanggeliang@kylinos.cn
Commands 'ss -M' are used in script mptcp_join.sh to display only MPTCP sockets. So it must be checked if ss tool supports MPTCP in this script.
Fixes: e274f7154008 ("selftests: mptcp: add subflow limits test-cases") Cc: stable@vger.kernel.org Signed-off-by: Geliang Tang tanggeliang@kylinos.cn Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index e68b1bc2c2e4..e4581b0dfb96 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -161,6 +161,11 @@ check_tools() exit $ksft_skip fi
+ if ! ss -h | grep -q MPTCP; then + echo "SKIP: ss tool does not support MPTCP" + exit $ksft_skip + fi + # Use the legacy version if available to support old kernel versions if iptables-legacy -V &> /dev/null; then iptables="iptables-legacy"
From: Davide Caratti dcaratti@redhat.com
when MPTCP server accepts an incoming connection, it clones its listener socket. However, the pointer to 'inet_opt' for the new socket has the same value as the original one: as a consequence, on program exit it's possible to observe the following splat:
BUG: KASAN: double-free in inet_sock_destruct+0x54f/0x8b0 Free of addr ffff888485950880 by task swapper/25/0
CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Not tainted 6.8.0-rc1+ #609 Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0 07/26/2013 Call Trace: <IRQ> dump_stack_lvl+0x32/0x50 print_report+0xca/0x620 kasan_report_invalid_free+0x64/0x90 __kasan_slab_free+0x1aa/0x1f0 kfree+0xed/0x2e0 inet_sock_destruct+0x54f/0x8b0 __sk_destruct+0x48/0x5b0 rcu_do_batch+0x34e/0xd90 rcu_core+0x559/0xac0 __do_softirq+0x183/0x5a4 irq_exit_rcu+0x12d/0x170 sysvec_apic_timer_interrupt+0x6b/0x80 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x16/0x20 RIP: 0010:cpuidle_enter_state+0x175/0x300 Code: 30 00 0f 84 1f 01 00 00 83 e8 01 83 f8 ff 75 e5 48 83 c4 18 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc fb 45 85 ed <0f> 89 60 ff ff ff 48 c1 e5 06 48 c7 43 18 00 00 00 00 48 83 44 2b RSP: 0018:ffff888481cf7d90 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff88887facddc8 RCX: 0000000000000000 RDX: 1ffff1110ff588b1 RSI: 0000000000000019 RDI: ffff88887fac4588 RBP: 0000000000000004 R08: 0000000000000002 R09: 0000000000043080 R10: 0009b02ea273363f R11: ffff88887fabf42b R12: ffffffff932592e0 R13: 0000000000000004 R14: 0000000000000000 R15: 00000022c880ec80 cpuidle_enter+0x4a/0xa0 do_idle+0x310/0x410 cpu_startup_entry+0x51/0x60 start_secondary+0x211/0x270 secondary_startup_64_no_verify+0x184/0x18b </TASK>
Allocated by task 6853: kasan_save_stack+0x1c/0x40 kasan_save_track+0x10/0x30 __kasan_kmalloc+0xa6/0xb0 __kmalloc+0x1eb/0x450 cipso_v4_sock_setattr+0x96/0x360 netlbl_sock_setattr+0x132/0x1f0 selinux_netlbl_socket_post_create+0x6c/0x110 selinux_socket_post_create+0x37b/0x7f0 security_socket_post_create+0x63/0xb0 __sock_create+0x305/0x450 __sys_socket_create.part.23+0xbd/0x130 __sys_socket+0x37/0xb0 __x64_sys_socket+0x6f/0xb0 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x6e/0x76
Freed by task 6858: kasan_save_stack+0x1c/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x12c/0x1f0 kfree+0xed/0x2e0 inet_sock_destruct+0x54f/0x8b0 __sk_destruct+0x48/0x5b0 subflow_ulp_release+0x1f0/0x250 tcp_cleanup_ulp+0x6e/0x110 tcp_v4_destroy_sock+0x5a/0x3a0 inet_csk_destroy_sock+0x135/0x390 tcp_fin+0x416/0x5c0 tcp_data_queue+0x1bc8/0x4310 tcp_rcv_state_process+0x15a3/0x47b0 tcp_v4_do_rcv+0x2c1/0x990 tcp_v4_rcv+0x41fb/0x5ed0 ip_protocol_deliver_rcu+0x6d/0x9f0 ip_local_deliver_finish+0x278/0x360 ip_local_deliver+0x182/0x2c0 ip_rcv+0xb5/0x1c0 __netif_receive_skb_one_core+0x16e/0x1b0 process_backlog+0x1e3/0x650 __napi_poll+0xa6/0x500 net_rx_action+0x740/0xbb0 __do_softirq+0x183/0x5a4
The buggy address belongs to the object at ffff888485950880 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff888485950880, ffff8884859508c0)
The buggy address belongs to the physical page: page:0000000056d1e95e refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888485950700 pfn:0x485950 flags: 0x57ffffc0000800(slab|node=1|zone=2|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 0057ffffc0000800 ffff88810004c640 ffffea00121b8ac0 dead000000000006 raw: ffff888485950700 0000000000200019 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff888485950780: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888485950800: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888485950880: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^ ffff888485950900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888485950980: 00 00 00 00 00 01 fc fc fc fc fc fc fc fc fc fc
Something similar (a refcount underflow) happens with CALIPSO/IPv6. Fix this by duplicating IP / IPv6 options after clone, so that ip{,6}_sock_destruct() doesn't end up freeing the same memory area twice.
Fixes: cf7da0d66cc1 ("mptcp: Create SUBFLOW socket for incoming connections") Cc: stable@vger.kernel.org Signed-off-by: Davide Caratti dcaratti@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/protocol.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2c8f931c6d5b..7833a49f6214 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3178,8 +3178,50 @@ static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
return (struct ipv6_pinfo *)(((u8 *)sk) + offset); } + +static void mptcp_copy_ip6_options(struct sock *newsk, const struct sock *sk) +{ + const struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + struct ipv6_pinfo *newnp; + + newnp = inet6_sk(newsk); + + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt) { + opt = ipv6_dup_options(newsk, opt); + if (!opt) + net_warn_ratelimited("%s: Failed to copy ip6 options\n", __func__); + } + RCU_INIT_POINTER(newnp->opt, opt); + rcu_read_unlock(); +} #endif
+static void mptcp_copy_ip_options(struct sock *newsk, const struct sock *sk) +{ + struct ip_options_rcu *inet_opt, *newopt = NULL; + const struct inet_sock *inet = inet_sk(sk); + struct inet_sock *newinet; + + newinet = inet_sk(newsk); + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + newopt = sock_kmalloc(newsk, sizeof(*inet_opt) + + inet_opt->opt.optlen, GFP_ATOMIC); + if (newopt) + memcpy(newopt, inet_opt, sizeof(*inet_opt) + + inet_opt->opt.optlen); + else + net_warn_ratelimited("%s: Failed to copy ip options\n", __func__); + } + RCU_INIT_POINTER(newinet->inet_opt, newopt); + rcu_read_unlock(); +} + struct sock *mptcp_sk_clone_init(const struct sock *sk, const struct mptcp_options_received *mp_opt, struct sock *ssk, @@ -3200,6 +3242,13 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk,
__mptcp_init_sock(nsk);
+#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (nsk->sk_family == AF_INET6) + mptcp_copy_ip6_options(nsk, sk); + else +#endif + mptcp_copy_ip_options(nsk, sk); + msk = mptcp_sk(nsk); msk->local_key = subflow_req->local_key; msk->token = subflow_req->token;
From: Paolo Abeni pabeni@redhat.com
Syzbot and Eric reported a lockdep splat in the subflow diag:
WARNING: possible circular locking dependency detected 6.8.0-rc4-syzkaller-00212-g40b9385dd8e6 #0 Not tainted
syz-executor.2/24141 is trying to acquire lock: ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline] ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137
but task is already holding lock: ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&h->lhash2[i].lock){+.+.}-{2:2}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __inet_hash+0x335/0xbe0 net/ipv4/inet_hashtables.c:743 inet_csk_listen_start+0x23a/0x320 net/ipv4/inet_connection_sock.c:1261 __inet_listen_sk+0x2a2/0x770 net/ipv4/af_inet.c:217 inet_listen+0xa3/0x110 net/ipv4/af_inet.c:239 rds_tcp_listen_init+0x3fd/0x5a0 net/rds/tcp_listen.c:316 rds_tcp_init_net+0x141/0x320 net/rds/tcp.c:577 ops_init+0x352/0x610 net/core/net_namespace.c:136 __register_pernet_operations net/core/net_namespace.c:1214 [inline] register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1283 register_pernet_device+0x33/0x80 net/core/net_namespace.c:1370 rds_tcp_init+0x62/0xd0 net/rds/tcp.c:735 do_one_initcall+0x238/0x830 init/main.c:1236 do_initcall_level+0x157/0x210 init/main.c:1298 do_initcalls+0x3f/0x80 init/main.c:1314 kernel_init_freeable+0x42f/0x5d0 init/main.c:1551 kernel_init+0x1d/0x2a0 init/main.c:1441 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
-> #0 (k-sk_lock-AF_INET6){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 lock_sock_fast include/net/sock.h:1723 [inline] subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28 tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline] tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137 inet_sk_diag_fill+0x10ed/0x1e00 net/ipv4/inet_diag.c:345 inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061 __inet_diag_dump+0x211/0x3a0 net/ipv4/inet_diag.c:1263 inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371 netlink_dump+0x59b/0xc80 net/netlink/af_netlink.c:2264 __netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:338 [inline] inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405 sock_diag_rcv_msg+0xe7/0x410 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77
As noted by Eric we can break the lock dependency chain avoid dumping any extended info for the mptcp subflow listener: nothing actually useful is presented there.
Fixes: b8adb69a7d29 ("mptcp: fix lockless access in subflow ULP diag") Cc: stable@vger.kernel.org Reported-by: Eric Dumazet edumazet@google.com Closes: https://lore.kernel.org/netdev/CANn89iJ=Oecw6OZDwmSYc9HJKQ_G32uN11L+oUcMu+TO... Suggested-by: Eric Dumazet edumazet@google.com Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/diag.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/mptcp/diag.c b/net/mptcp/diag.c index 6ff6f14674aa..7017dd60659d 100644 --- a/net/mptcp/diag.c +++ b/net/mptcp/diag.c @@ -21,6 +21,9 @@ static int subflow_get_info(struct sock *sk, struct sk_buff *skb) bool slow; int err;
+ if (inet_sk_state_load(sk) == TCP_LISTEN) + return 0; + start = nla_nest_start_noflag(skb, INET_ULP_INFO_MPTCP); if (!start) return -EMSGSIZE;
Hello:
This series was applied to netdev/net.git (main) by Jakub Kicinski kuba@kernel.org:
On Fri, 23 Feb 2024 17:14:10 +0100 you wrote:
This series includes 6 types of fixes:
- Patch 1 fixes v4 mapped in v6 addresses support for the userspace PM, when asking to delete a subflow. It was done everywhere else, but not there. Patch 2 validates the modification, thanks to a subtest in mptcp_join.sh. These patches can be backported up to v5.19.
[...]
Here is the summary with links: - [net,01/10] mptcp: map v4 address to v6 when destroying subflow https://git.kernel.org/netdev/net/c/535d620ea5ff - [net,02/10] selftests: mptcp: rm subflow with v4/v4mapped addr https://git.kernel.org/netdev/net/c/7092dbee2328 - [net,03/10] mptcp: avoid printing warning once on client side https://git.kernel.org/netdev/net/c/5b49c41ac8f2 - [net,04/10] mptcp: push at DSS boundaries https://git.kernel.org/netdev/net/c/b9cd26f640a3 - [net,05/10] mptcp: fix snd_wnd initialization for passive socket https://git.kernel.org/netdev/net/c/adf1bb78dab5 - [net,06/10] mptcp: fix potential wake-up event loss https://git.kernel.org/netdev/net/c/b111d8fbd2cb - [net,07/10] selftests: mptcp: join: add ss mptcp support check https://git.kernel.org/netdev/net/c/9480f388a2ef - [net,08/10] mptcp: fix double-free on socket dismantle https://git.kernel.org/netdev/net/c/10048689def7 - [net,09/10] mptcp: fix possible deadlock in subflow diag https://git.kernel.org/netdev/net/c/d6a9608af9a7 - [net,10/10] selftests: mptcp: explicitly trigger the listener diag code-path https://git.kernel.org/netdev/net/c/b4b51d36bbaa
You are awesome, thank you!
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