summaryrefslogtreecommitdiff
path: root/net/mptcp
AgeCommit message (Collapse)AuthorFilesLines
2022-12-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni2-10/+55
Merge in the left-over fixes before the net-next pull-request. net/mptcp/subflow.c d3295fee3c75 ("mptcp: use proper req destructor for IPv6") 36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()") Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-12-12mptcp: use proper req destructor for IPv6Matthieu Baerts1-3/+16
Before, only the destructor from TCP request sock in IPv4 was called even if the subflow was IPv6. It is important to use the right destructor to avoid memory leaks with some advanced IPv6 features, e.g. when the request socks contain specific IPv6 options. Fixes: 79c0949e9a09 ("mptcp: Add key generation and token tree") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-12mptcp: dedicated request sock for subflow in v6Matthieu Baerts1-8/+26
tcp_request_sock_ops structure is specific to IPv4. It should then not be used with MPTCP subflows on top of IPv6. For example, it contains the 'family' field, initialised to AF_INET. This 'family' field is used by TCP FastOpen code to generate the cookie but also by TCP Metrics, SELinux and SYN Cookies. Using the wrong family will not lead to crashes but displaying/using/checking wrong things. Note that 'send_reset' callback from request_sock_ops structure is used in some error paths. It is then also important to use the correct one for IPv4 or IPv6. The slab name can also be different in IPv4 and IPv6, it will be used when printing some log messages. The slab pointer will anyway be the same because the object size is the same for both v4 and v6. A BUILD_BUG_ON() has also been added to make sure this size is the same. Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-12mptcp: remove MPTCP 'ifdef' in TCP SYN cookiesMatthieu Baerts1-1/+11
To ease the maintenance, it is often recommended to avoid having #ifdef preprocessor conditions. Here the section related to CONFIG_MPTCP was quite short but the next commit needs to add more code around. It is then cleaner to move specific MPTCP code to functions located in net/mptcp directory. Now that mptcp_subflow_request_sock_ops structure can be static, it can also be marked as "read only after init". Suggested-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-12mptcp: netlink: fix some error return codeWei Yongjun1-0/+4
Fix to return negative error code -EINVAL from some error handling case instead of 0, as done elsewhere in those functions. Fixes: 9ab4807c84a4 ("mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE") Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment") Cc: stable@vger.kernel.org Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-09mptcp: return 0 instead of 'err' varMatthieu Baerts2-3/+3
When 'err' is 0, it looks clearer to return '0' instead of the variable called 'err'. The behaviour is then not modified, just a clearer code. By doing this, we can also avoid false positive smatch warnings like this one: net/mptcp/pm_netlink.c:1169 mptcp_pm_parse_pm_addr_attr() warn: missing error code? 'err' Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-09mptcp: use nlmsg_free instead of kfree_skbGeliang Tang1-4/+4
Use nlmsg_free() instead of kfree_skb() in pm_netlink.c. The SKB's have been created by nlmsg_new(). The proper cleaning way should then be done with nlmsg_free(). For the moment, nlmsg_free() is simply calling kfree_skb() so we don't change the behaviour here. Suggested-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-01mptcp: add pm listener eventsGeliang Tang3-0/+62
This patch adds two new MPTCP netlink event types for PM listening socket create and close, named MPTCP_EVENT_LISTENER_CREATED and MPTCP_EVENT_LISTENER_CLOSED. Add a new function mptcp_event_pm_listener() to push the new events with family, port and addr to userspace. Invoke mptcp_event_pm_listener() with MPTCP_EVENT_LISTENER_CREATED in mptcp_listen() and mptcp_pm_nl_create_listen_socket(), invoke it with MPTCP_EVENT_LISTENER_CLOSED in __mptcp_close_ssk(). Signed-off-by: Geliang Tang <geliang.tang@suse.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: add support for TCP_FASTOPEN_KEY sockoptMatthieu Baerts1-3/+3
The goal of this socket option is to set different keys per listener, see commit 1fba70e5b6be ("tcp: socket option to set TCP fast open key") for more details about this socket option. The only thing to do here with MPTCP is to relay the request to the first subflow like it is already done for the other TCP_FASTOPEN* socket options. Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: add TCP_FASTOPEN sock optionDmytro Shytyi1-1/+4
The TCP_FASTOPEN socket option is one way for the application to tell the kernel TFO support has to be enabled for the listener socket. The only thing to do here with MPTCP is to relay the request to the first subflow like it is already done for the other TCP_FASTOPEN* socket options. Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: add subflow_v(4,6)_send_synack()Dmytro Shytyi4-1/+92
The send_synack() needs to be overridden for MPTCP to support TFO for two reasons: - There is not be enough space in the TCP options if the TFO cookie has to be added in the SYN+ACK with other options: MSS (4), SACK OK (2), Timestamps (10), Window Scale (3+1), TFO (10+2), MP_CAPABLE (12). MPTCPv1 specs -- RFC 8684, section B.1 [1] -- suggest to drop the TCP timestamps option in this case. - The data received in the SYN has to be handled: the SKB can be dequeued from the subflow sk and transferred to the MPTCP sk. Counters need to be updated accordingly and the application can be notified at the end because some bytes have been received. [1] https://www.rfc-editor.org/rfc/rfc8684.html#section-b.1 Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: implement delayed seq generation for passive fastopenDmytro Shytyi6-15/+54
With fastopen in place, the first subflow socket is created before the MPC handshake completes, and we need to properly initialize the sequence numbers at MPC ACK reception. Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: consolidate initial ack seq generationPaolo Abeni4-45/+45
Currently the initial ack sequence is generated on demand whenever it's requested and the remote key is handy. The relevant code is scattered in different places and can lead to multiple, unneeded, crypto operations. This change consolidates the ack sequence generation code in a single helper, storing the sequence number at the subflow level. The above additionally saves a few conditional in fast-path and will simplify the upcoming fast-open implementation. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: track accurately the incoming MPC suboption typePaolo Abeni1-3/+8
Currently in the receive path we don't need to discriminate between MPC SYN, MPC SYN-ACK and MPC ACK, but soon the fastopen code will need that info to properly track the fully established status. Track the exact MPC suboption type into the receive opt bitmap. No functional change intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29mptcp: add MSG_FASTOPEN sendmsg flag supportDmytro Shytyi1-6/+3
Since commit 54f1944ed6d2 ("mptcp: factor out mptcp_connect()"), all the infrastructure is now in place to support the MSG_FASTOPEN flag, we just need to call into the fastopen path in mptcp_sendmsg(). Co-developed-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-10/+9
tools/lib/bpf/ringbuf.c 927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap") b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c") https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-28mptcp: fix sleep in atomic at close timePaolo Abeni1-3/+3
Matt reported a splat at msk close time: BUG: sleeping function called from invalid context at net/mptcp/protocol.c:2877 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 155, name: packetdrill preempt_count: 201, expected: 0 RCU nest depth: 0, expected: 0 4 locks held by packetdrill/155: #0: ffff888001536990 (&sb->s_type->i_mutex_key#6){+.+.}-{3:3}, at: __sock_release (net/socket.c:650) #1: ffff88800b498130 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close (net/mptcp/protocol.c:2973) #2: ffff88800b49a130 (sk_lock-AF_INET/1){+.+.}-{0:0}, at: __mptcp_close_ssk (net/mptcp/protocol.c:2363) #3: ffff88800b49a0b0 (slock-AF_INET){+...}-{2:2}, at: __lock_sock_fast (include/net/sock.h:1820) Preemption disabled at: 0x0 CPU: 1 PID: 155 Comm: packetdrill Not tainted 6.1.0-rc5 #365 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) __might_resched.cold (kernel/sched/core.c:9891) __mptcp_destroy_sock (include/linux/kernel.h:110) __mptcp_close (net/mptcp/protocol.c:2959) mptcp_subflow_queue_clean (include/net/sock.h:1777) __mptcp_close_ssk (net/mptcp/protocol.c:2363) mptcp_destroy_common (net/mptcp/protocol.c:3170) mptcp_destroy (include/net/sock.h:1495) __mptcp_destroy_sock (net/mptcp/protocol.c:2886) __mptcp_close (net/mptcp/protocol.c:2959) mptcp_close (net/mptcp/protocol.c:2974) inet_release (net/ipv4/af_inet.c:432) __sock_release (net/socket.c:651) sock_close (net/socket.c:1367) __fput (fs/file_table.c:320) task_work_run (kernel/task_work.c:181 (discriminator 1)) exit_to_user_mode_prepare (include/linux/resume_user_mode.h:49) syscall_exit_to_user_mode (kernel/entry/common.c:130) do_syscall_64 (arch/x86/entry/common.c:87) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) We can't call mptcp_close under the 'fast' socket lock variant, replace it with a sock_lock_nested() as the relevant code is already under the listening msk socket lock protection. Reported-by: Matthieu Baerts <matthieu.baerts@tessares.net> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/316 Fixes: 30e51b923e43 ("mptcp: fix unreleased socket in accept queue") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-28mptcp: don't orphan ssk in mptcp_close()Menglong Dong1-7/+6
All of the subflows of a msk will be orphaned in mptcp_close(), which means the subflows are in DEAD state. After then, DATA_FIN will be sent, and the other side will response with a DATA_ACK for this DATA_FIN. However, if the other side still has pending data, the data that received on these subflows will not be passed to the msk, as they are DEAD and subflow_data_ready() will not be called in tcp_data_ready(). Therefore, these data can't be acked, and they will be retransmitted again and again, until timeout. Fix this by setting ssk->sk_socket and ssk->sk_wq to 'NULL', instead of orphaning the subflows in __mptcp_close(), as Paolo suggested. Fixes: e16163b6e2b7 ("mptcp: refactor shutdown and close") Reviewed-by: Biao Jiang <benbjiang@tencent.com> Reviewed-by: Mengen Sun <mengensun@tencent.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Reviewed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-21mptcp: more detailed error reporting on endpoint creationPaolo Abeni1-11/+13
Endpoint creation can fail for a number of reasons; in case of failure append the error number to the extended ack message, using a newly introduced generic helper. Additionally let mptcp_pm_nl_append_new_local_addr() report different error reasons. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-21mptcp: deduplicate error paths on endpoint creationPaolo Abeni1-22/+13
When endpoint creation fails, we need to free the newly allocated entry and eventually destroy the paired mptcp listener socket. Consolidate such action in a single point let all the errors path reach it. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-11mptcp: Fix grammar in a commentMat Martineau1-2/+2
We kept getting initial patches from new contributors to remove a duplicate 'the' (since grammar checking scripts flag it), but submitters never followed up after code review. Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-11mptcp: get sk from msk directlyGeliang Tang3-6/+6
Use '(struct sock *)msk' to get 'sk' from 'msk' in a more direct way instead of using '&msk->sk.icsk_inet.sk'. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-11mptcp: change 'first' as a parameterGeliang Tang1-14/+6
The function mptcp_subflow_process_delegated() uses the input ssk first, while __mptcp_check_push() invokes the packet scheduler first. So this patch adds a new parameter named 'first' for the function __mptcp_subflow_push_pending() to deal with these two cases separately. With this change, the code that invokes the packet scheduler in the function __mptcp_check_push() can be removed, and replaced by invoking __mptcp_subflow_push_pending() directly. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-11mptcp: use msk instead of mptcp_skGeliang Tang1-5/+5
Use msk instead of mptcp_sk(sk) in the functions where the variable "msk = mptcp_sk(sk)" has been defined. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski3-81/+113
drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c 2871edb32f46 ("can: kvaser_usb: Fix possible completions during init_completion") abb8670938b2 ("can: kvaser_usb_leaf: Ignore stale bus-off after start") 8d21f5927ae6 ("can: kvaser_usb_leaf: Fix improved state not being reported") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-26mptcp: fix tracking issue in mptcp_subflow_create_socket()Eric Dumazet1-0/+2
My recent patch missed that mptcp_subflow_create_socket() was creating a 'kernel' socket, then converted it to 'user' socket. Fixes: 0cafd77dcd03 ("net: add a refcount tracker for kernel sockets") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Link: https://lore.kernel.org/r/20221025180546.652251-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-25mptcp: sockopt: use new helper for TCP_DEFER_ACCEPTMatthieu Baerts1-13/+3
mptcp_setsockopt_sol_tcp_defer() was doing the same thing as mptcp_setsockopt_first_sf_only() except for the returned code in case of error. Ignoring the error is needed to mimic how TCP_DEFER_ACCEPT is handled when used with "plain" TCP sockets. The specific function for TCP_DEFER_ACCEPT can be replaced by the new mptcp_setsockopt_first_sf_only() helper and errors can be ignored to stay compatible with TCP. A bit of cleanup. Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-10-25mptcp: add TCP_FASTOPEN_NO_COOKIE supportMatthieu Baerts1-2/+5
The goal of this socket option is to configure MPTCP + TFO without cookie per socket. It was already possible to enable TFO without a cookie per netns by setting net.ipv4.tcp_fastopen sysctl knob to the right value. Per route was also supported by setting 'fastopen_no_cookie' option. This patch adds a per socket support like it is possible to do with TCP thanks to TCP_FASTOPEN_NO_COOKIE socket option. The only thing to do here is to relay the request to the first subflow like it is already done for TCP_FASTOPEN_CONNECT. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-10-25mptcp: sockopt: make 'tcp_fastopen_connect' genericMatthieu Baerts1-5/+6
There are other socket options that need to act only on the first subflow, e.g. all TCP_FASTOPEN* socket options. This is similar to the getsockopt version. In the next commit, this new mptcp_setsockopt_first_sf_only() helper is used by other another option. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-10-24mptcp: fix abba deadlock on fastopenPaolo Abeni1-15/+34
Our CI reported lockdep splat in the fastopen code: ====================================================== WARNING: possible circular locking dependency detected 6.0.0.mptcp_f5e8bfe9878d+ #1558 Not tainted ------------------------------------------------------ packetdrill/1071 is trying to acquire lock: ffff8881bd198140 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_wait_for_connect+0x19c/0x310 but task is already holding lock: ffff8881b8346540 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0xfdf/0x1740 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (k-sk_lock-AF_INET){+.+.}-{0:0}: __lock_acquire+0xb6d/0x1860 lock_acquire+0x1d8/0x620 lock_sock_nested+0x37/0xd0 inet_stream_connect+0x3f/0xa0 mptcp_connect+0x411/0x800 __inet_stream_connect+0x3ab/0x800 mptcp_stream_connect+0xac/0x110 __sys_connect+0x101/0x130 __x64_sys_connect+0x6e/0xb0 do_syscall_64+0x59/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sk_lock-AF_INET){+.+.}-{0:0}: check_prev_add+0x15e/0x2110 validate_chain+0xace/0xdf0 __lock_acquire+0xb6d/0x1860 lock_acquire+0x1d8/0x620 lock_sock_nested+0x37/0xd0 inet_wait_for_connect+0x19c/0x310 __inet_stream_connect+0x26c/0x800 tcp_sendmsg_fastopen+0x341/0x650 mptcp_sendmsg+0x109d/0x1740 sock_sendmsg+0xe1/0x120 __sys_sendto+0x1c7/0x2a0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x59/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(k-sk_lock-AF_INET); lock(sk_lock-AF_INET); lock(k-sk_lock-AF_INET); lock(sk_lock-AF_INET); *** DEADLOCK *** 1 lock held by packetdrill/1071: #0: ffff8881b8346540 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0xfdf/0x1740 ====================================================== The problem is caused by the blocking inet_wait_for_connect() releasing and re-acquiring the msk socket lock while the subflow socket lock is still held and the MPTCP socket requires that the msk socket lock must be acquired before the subflow socket lock. Address the issue always invoking tcp_sendmsg_fastopen() in an unblocking manner, and later eventually complete the blocking __inet_stream_connect() as needed. Fixes: d98a82a6afc7 ("mptcp: handle defer connect in mptcp_sendmsg") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-24mptcp: factor out mptcp_connect()Paolo Abeni2-67/+73
The current MPTCP connect implementation duplicates a bit of inet code and does not use nor provide a struct proto->connect callback, which in turn will not fit the upcoming fastopen implementation. Refactor such implementation to use the common helper, moving the MPTCP-specific bits into mptcp_connect(). Additionally, avoid an indirect call to the subflow connect callback. Note that the fastopen call-path invokes mptcp_connect() while already holding the subflow socket lock. Explicitly keep track of such path via a new MPTCP-level flag and handle the locking accordingly. Additionally, track the connect flags in a new msk field to allow propagating them to the subflow inet_stream_connect call. Fixes: d98a82a6afc7 ("mptcp: handle defer connect in mptcp_sendmsg") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-24mptcp: set msk local address earlierPaolo Abeni3-2/+9
The mptcp_pm_nl_get_local_id() code assumes that the msk local address is available at that point. For passive sockets, we initialize such address at accept() time. Depending on the running configuration and the user-space timing, a passive MPJ subflow can join the msk socket before accept() completes. In such case, the PM assigns a wrong local id to the MPJ subflow and later PM netlink operations will end-up touching the wrong/unexpected subflow. All the above causes sporadic self-tests failures, especially when the host is heavy loaded. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/308 Fixes: 01cacb00b35c ("mptcp: add netlink-based PM") Fixes: d045b9eb95a9 ("mptcp: introduce implicit endpoints") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-24net: introduce and use custom sockopt socket flagPaolo Abeni1-0/+4
We will soon introduce custom setsockopt for UDP sockets, too. Instead of doing even more complex arbitrary checks inside sock_use_custom_sol_socket(), add a new socket flag and set it for the relevant socket types (currently only MPTCP). Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-24inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().Kuniyuki Iwashima1-7/+0
After commit d38afeec26ed ("tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in sk->sk_destruct() by setting inet6_sock_destruct() to it to make sure we do not leak inet6-specific resources. Now we can remove unnecessary inet6_destroy_sock() calls in sk->sk_prot->destroy(). DCCP and SCTP have their own sk->sk_destruct() function, so we change them separately in the following patches. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-03mptcp: update misleading comments.Paolo Abeni1-7/+7
The MPTCP data path is quite complex and hard to understend even without some foggy comments referring to modified code and/or completely misleading from the beginning. Update a few of them to more accurately describing the current status. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-03mptcp: use fastclose on more edge scenariosPaolo Abeni1-19/+44
Daire reported a user-space application hang-up when the peer is forcibly closed before the data transfer completion. The relevant application expects the peer to either do an application-level clean shutdown or a transport-level connection reset. We can accommodate a such user by extending the fastclose usage: at fd close time, if the msk socket has some unread data, and at FIN_WAIT timeout. Note that at MPTCP close time we must ensure that the TCP subflows will reset: set the linger socket option to a suitable value. Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-03mptcp: propagate fastclose errorPaolo Abeni1-11/+36
When an mptcp socket is closed due to an incoming FASTCLOSE option, so specific sk_err is set and later syscall will fail usually with EPIPE. Align the current fastclose error handling with TCP reset, properly setting the socket error according to the current msk state and propagating such error. Additionally sendmsg() is currently not handling properly the sk_err, always returning EPIPE. Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski3-29/+22
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28mptcp: fix unreleased socket in accept queueMenglong Dong3-27/+9
The mptcp socket and its subflow sockets in accept queue can't be released after the process exit. While the release of a mptcp socket in listening state, the corresponding tcp socket will be released too. Meanwhile, the tcp socket in the unaccept queue will be released too. However, only init subflow is in the unaccept queue, and the joined subflow is not in the unaccept queue, which makes the joined subflow won't be released, and therefore the corresponding unaccepted mptcp socket will not be released to. This can be reproduced easily with following steps: 1. create 2 namespace and veth: $ ip netns add mptcp-client $ ip netns add mptcp-server $ sysctl -w net.ipv4.conf.all.rp_filter=0 $ ip netns exec mptcp-client sysctl -w net.mptcp.enabled=1 $ ip netns exec mptcp-server sysctl -w net.mptcp.enabled=1 $ ip link add red-client netns mptcp-client type veth peer red-server \ netns mptcp-server $ ip -n mptcp-server address add 10.0.0.1/24 dev red-server $ ip -n mptcp-server address add 192.168.0.1/24 dev red-server $ ip -n mptcp-client address add 10.0.0.2/24 dev red-client $ ip -n mptcp-client address add 192.168.0.2/24 dev red-client $ ip -n mptcp-server link set red-server up $ ip -n mptcp-client link set red-client up 2. configure the endpoint and limit for client and server: $ ip -n mptcp-server mptcp endpoint flush $ ip -n mptcp-server mptcp limits set subflow 2 add_addr_accepted 2 $ ip -n mptcp-client mptcp endpoint flush $ ip -n mptcp-client mptcp limits set subflow 2 add_addr_accepted 2 $ ip -n mptcp-client mptcp endpoint add 192.168.0.2 dev red-client id \ 1 subflow 3. listen and accept on a port, such as 9999. The nc command we used here is modified, which makes it use mptcp protocol by default. $ ip netns exec mptcp-server nc -l -k -p 9999 4. open another *two* terminal and use each of them to connect to the server with the following command: $ ip netns exec mptcp-client nc 10.0.0.1 9999 Input something after connect to trigger the connection of the second subflow. So that there are two established mptcp connections, with the second one still unaccepted. 5. exit all the nc command, and check the tcp socket in server namespace. And you will find that there is one tcp socket in CLOSE_WAIT state and can't release forever. Fix this by closing all of the unaccepted mptcp socket in mptcp_subflow_queue_clean() with __mptcp_close(). Now, we can ensure that all unaccepted mptcp sockets will be cleaned by __mptcp_close() before they are released, so mptcp_sock_destruct(), which is used to clean the unaccepted mptcp socket, is not needed anymore. The selftests for mptcp is ran for this commit, and no new failures. Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Fixes: 6aeed9045071 ("mptcp: fix race on unaccepted mptcp sockets") Cc: stable@vger.kernel.org Reviewed-by: Jiang Biao <benbjiang@tencent.com> Reviewed-by: Mengen Sun <mengensun@tencent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28mptcp: factor out __mptcp_close() without socket lockMenglong Dong2-2/+13
Factor out __mptcp_close() from mptcp_close(). The caller of __mptcp_close() should hold the socket lock, and cancel mptcp work when __mptcp_close() returns true. This function will be used in the next commit. Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Fixes: 6aeed9045071 ("mptcp: fix race on unaccepted mptcp sockets") Cc: stable@vger.kernel.org Reviewed-by: Jiang Biao <benbjiang@tencent.com> Reviewed-by: Mengen Sun <mengensun@tencent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28mptcp: poll allow write call before actual connectBenjamin Hesmans1-0/+4
If fastopen is used, poll must allow a first write that will trigger the SYN+data Similar to what is done in tcp_poll(). Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28mptcp: handle defer connect in mptcp_sendmsgDmytro Shytyi1-0/+22
When TCP_FASTOPEN_CONNECT has been set on the socket before a connect, the defer flag is set and must be handled when sendmsg is called. This is similar to what is done in tcp_sendmsg_locked(). Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Co-developed-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28mptcp: add TCP_FASTOPEN_CONNECT socket optionBenjamin Hesmans1-1/+18
Set the option for the first subflow only. For the other subflows TFO can't be used because a mapping would be needed to cover the data in the SYN. Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+7
drivers/net/ethernet/freescale/fec.h 7b15515fc1ca ("Revert "fec: Restart PPS after link state change"") 40c79ce13b03 ("net: fec: add stop mode support for imx8 platform") https://lore.kernel.org/all/20220921105337.62b41047@canb.auug.org.au/ drivers/pinctrl/pinctrl-ocelot.c c297561bc98a ("pinctrl: ocelot: Fix interrupt controller") 181f604b33cd ("pinctrl: ocelot: add ability to be used in a non-mmio configuration") https://lore.kernel.org/all/20220921110032.7cd28114@canb.auug.org.au/ tools/testing/selftests/drivers/net/bonding/Makefile bbb774d921e2 ("net: Add tests for bonding and team address list management") 152e8ec77640 ("selftests/bonding: add a test for bonding lladdr target") https://lore.kernel.org/all/20220921110437.5b7dbd82@canb.auug.org.au/ drivers/net/can/usb/gs_usb.c 5440428b3da6 ("can: gs_usb: gs_can_open(): fix race dev->can.state condition") 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support") https://lore.kernel.org/all/84f45a7d-92b6-4dc5-d7a1-072152fab6ff@tessares.net/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-20tcp: Access &tcp_hashinfo via net.Kuniyuki Iwashima1-2/+5
We will soon introduce an optional per-netns ehash. This means we cannot use tcp_hashinfo directly in most places. Instead, access it via net->ipv4.tcp_death_row.hashinfo. The access will be valid only while initialising tcp_hashinfo itself and creating/destroying each netns. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-15mptcp: account memory allocation in mptcp_nl_cmd_add_addr() to userThomas Haller1-1/+1
Now that non-root users can configure MPTCP endpoints, account the memory allocation to the user. Signed-off-by: Thomas Haller <thaller@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-15mptcp: allow privileged operations from user namespacesThomas Haller1-9/+9
GENL_ADMIN_PERM checks that the user has CAP_NET_ADMIN in the initial namespace by calling netlink_capable(). Instead, use GENL_UNS_ADMIN_PERM which uses netlink_ns_capable(). This checks that the caller has CAP_NET_ADMIN in the current user namespace. See also commit 4a92602aa1cd ("openvswitch: allow management from inside user namespaces") which introduced this mechanism. See also commit 5617c6cd6f84 ("nl80211: Allow privileged operations from user namespaces") which introduced this for nl80211. Signed-off-by: Thomas Haller <thaller@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-15mptcp: add do_check_data_fin to replace copiedGeliang Tang1-3/+4
This patch adds a new bool variable 'do_check_data_fin' to replace the original int variable 'copied' in __mptcp_push_pending(), check it to determine whether to call __mptcp_check_send_data_fin(). Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-15mptcp: add mptcp_for_each_subflow_safe helperMatthieu Baerts3-4/+6
Similar to mptcp_for_each_subflow(): this is clearer now that the _safe version is used in multiple places. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-13mptcp: fix fwd memory accounting on coalescePaolo Abeni1-1/+7
The intel bot reported a memory accounting related splat: [ 240.473094] ------------[ cut here ]------------ [ 240.478507] page_counter underflow: -4294828518 nr_pages=4294967290 [ 240.485500] WARNING: CPU: 2 PID: 14986 at mm/page_counter.c:56 page_counter_cancel+0x96/0xc0 [ 240.570849] CPU: 2 PID: 14986 Comm: mptcp_connect Tainted: G S 5.19.0-rc4-00739-gd24141fe7b48 #1 [ 240.581637] Hardware name: HP HP Z240 SFF Workstation/802E, BIOS N51 Ver. 01.63 10/05/2017 [ 240.590600] RIP: 0010:page_counter_cancel+0x96/0xc0 [ 240.596179] Code: 00 00 00 45 31 c0 48 89 ef 5d 4c 89 c6 41 5c e9 40 fd ff ff 4c 89 e2 48 c7 c7 20 73 39 84 c6 05 d5 b1 52 04 01 e8 e7 95 f3 01 <0f> 0b eb a9 48 89 ef e8 1e 25 fc ff eb c3 66 66 2e 0f 1f 84 00 00 [ 240.615639] RSP: 0018:ffffc9000496f7c8 EFLAGS: 00010082 [ 240.621569] RAX: 0000000000000000 RBX: ffff88819c9c0120 RCX: 0000000000000000 [ 240.629404] RDX: 0000000000000027 RSI: 0000000000000004 RDI: fffff5200092deeb [ 240.637239] RBP: ffff88819c9c0120 R08: 0000000000000001 R09: ffff888366527a2b [ 240.645069] R10: ffffed106cca4f45 R11: 0000000000000001 R12: 00000000fffffffa [ 240.652903] R13: ffff888366536118 R14: 00000000fffffffa R15: ffff88819c9c0000 [ 240.660738] FS: 00007f3786e72540(0000) GS:ffff888366500000(0000) knlGS:0000000000000000 [ 240.669529] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 240.675974] CR2: 00007f966b346000 CR3: 0000000168cea002 CR4: 00000000003706e0 [ 240.683807] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 240.691641] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 240.699468] Call Trace: [ 240.702613] <TASK> [ 240.705413] page_counter_uncharge+0x29/0x80 [ 240.710389] drain_stock+0xd0/0x180 [ 240.714585] refill_stock+0x278/0x580 [ 240.718951] __sk_mem_reduce_allocated+0x222/0x5c0 [ 240.729248] __mptcp_update_rmem+0x235/0x2c0 [ 240.734228] __mptcp_move_skbs+0x194/0x6c0 [ 240.749764] mptcp_recvmsg+0xdfa/0x1340 [ 240.763153] inet_recvmsg+0x37f/0x500 [ 240.782109] sock_read_iter+0x24a/0x380 [ 240.805353] new_sync_read+0x420/0x540 [ 240.838552] vfs_read+0x37f/0x4c0 [ 240.842582] ksys_read+0x170/0x200 [ 240.864039] do_syscall_64+0x5c/0x80 [ 240.872770] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 240.878526] RIP: 0033:0x7f3786d9ae8e [ 240.882805] Code: c0 e9 b6 fe ff ff 50 48 8d 3d 6e 18 0a 00 e8 89 e8 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28 [ 240.902259] RSP: 002b:00007fff7be81e08 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 240.910533] RAX: ffffffffffffffda RBX: 0000000000002000 RCX: 00007f3786d9ae8e [ 240.918368] RDX: 0000000000002000 RSI: 00007fff7be87ec0 RDI: 0000000000000005 [ 240.926206] RBP: 0000000000000005 R08: 00007f3786e6a230 R09: 00007f3786e6a240 [ 240.934046] R10: fffffffffffff288 R11: 0000000000000246 R12: 0000000000002000 [ 240.941884] R13: 00007fff7be87ec0 R14: 00007fff7be87ec0 R15: 0000000000002000 [ 240.949741] </TASK> [ 240.952632] irq event stamp: 27367 [ 240.956735] hardirqs last enabled at (27366): [<ffffffff81ba50ea>] mem_cgroup_uncharge_skmem+0x6a/0x80 [ 240.966848] hardirqs last disabled at (27367): [<ffffffff81b8fd42>] refill_stock+0x282/0x580 [ 240.976017] softirqs last enabled at (27360): [<ffffffff83a4d8ef>] mptcp_recvmsg+0xaf/0x1340 [ 240.985273] softirqs last disabled at (27364): [<ffffffff83a4d30c>] __mptcp_move_skbs+0x18c/0x6c0 [ 240.994872] ---[ end trace 0000000000000000 ]--- After commit d24141fe7b48 ("mptcp: drop SK_RECLAIM_* macros"), if rmem_fwd_alloc become negative, mptcp_rmem_uncharge() can try to reclaim a negative amount of pages, since the expression: reclaimable >= PAGE_SIZE will evaluate to true for any negative value of the int 'reclaimable': 'PAGE_SIZE' is an unsigned long and the negative integer will be promoted to a (very large) unsigned long value. Still after the mentioned commit, kfree_skb_partial() in mptcp_try_coalesce() will reclaim most of just released fwd memory, so that following charging of the skb delta size will lead to negative fwd memory values. At that point a racing recvmsg() can trigger the splat. Address the issue switching the order of the memory accounting operations. The fwd memory can still transiently reach negative values, but that will happen in an atomic scope and no code path could touch/use such value. Reported-by: kernel test robot <oliver.sang@intel.com> Fixes: d24141fe7b48 ("mptcp: drop SK_RECLAIM_* macros") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Link: https://lore.kernel.org/r/20220906180404.1255873-1-matthieu.baerts@tessares.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 14:48:17 +0000