kernel/linux.git/net/sctp/protocol.c, branch v7.2-rc5

sctp: close UDP tunnel sockets during netns teardown

2026-07-21T21:03:32+00:00

proc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when net.sctp.udp_port is set, and stops/restarts them when the sysctl value changes. The netns exit path does not stop these sockets, so a namespace can be torn down while its SCTP UDP tunnel sockets are still installed. Close the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering the per-net sysctl table. This prevents new sysctl writes from racing in while the sockets are being released, and closes the sockets before the control socket is destroyed. Fixes: 046c052b475e ("sctp: enable udp tunneling socks") Cc: stable@vger.kernel.org Reported-by: Sashiko Closes: https://sashiko.dev/#/patchset/b9f1f02b0780ad6a719e2413f5f0bb8eb7702d94.1782585631.git.roxy520tt%40gmail.com Signed-off-by: Zhiling Zou Signed-off-by: Ren Wei Acked-by: Xin Long Link: https://patch.msgid.link/6dab75f22855cb219e2e30a5497cab03b970ab91.1784033357.git.roxy520tt@gmail.com Signed-off-by: Jakub Kicinski

sctp: avoid auth_enable sysctl UAF during netns teardown

2026-07-21T21:03:32+00:00

proc_sctp_do_auth() updates the SCTP control socket after changing net.sctp.auth_enable. The handler gets the per-net SCTP state from ctl->data, so an already opened sysctl file can still target a network namespace while that namespace is being torn down. SCTP previously registered its per-net sysctls from sctp_defaults_init(), while the control socket is created later from sctp_ctrlsock_init(). This exposed a window during initialization where auth_enable was writable before net->sctp.ctl_sock existed, and a teardown window where auth_enable stayed writable after inet_ctl_sock_destroy() had released the control socket. Move the per-net SCTP sysctl registration into sctp_ctrlsock_init() after sctp_ctl_sock_init() succeeds, and unregister the sysctl table before destroying the control socket in sctp_ctrlsock_exit(). If sysctl registration fails after the control socket was created, destroy the control socket in the same init path. Make sctp_sysctl_net_unregister() tolerate a missing header and clear the saved pointer so init-error and exit paths can safely share the unregister helper. Fixes: 15649fd5415e ("sctp: sysctl: auth_enable: avoid using current->nsproxy") Cc: stable@vger.kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Co-developed-by: Qi Tang Signed-off-by: Qi Tang Signed-off-by: Zhiling Zou Signed-off-by: Ren Wei Acked-by: Xin Long Link: https://patch.msgid.link/390cd5e91ed60eea27b0b64d0468301a9e73b808.1784033357.git.roxy520tt@gmail.com Signed-off-by: Jakub Kicinski

sctp: fix addr_wq_timer race in sctp_free_addr_wq()

2026-06-30T23:58:59+00:00

sctp_free_addr_wq() previously removed addr_wq_timer using timer_delete() while holding addr_wq_lock. However, timer_delete() does not guarantee that a currently running timer handler has completed. This allows a race with sctp_addr_wq_timeout_handler(), where the handler may still run after addr_waitq has been freed, acquire addr_wq_lock, and access freed memory, leading to a use-after-free. Fix this by calling timer_shutdown_sync() before taking addr_wq_lock. This guarantees that any in-flight timer handler has finished and prevents the timer from being re-armed during teardown, making subsequent cleanup safe. Fixes: 4db67e808640 ("sctp: Make the address lists per network namespace") Reported-by: Sashiko Signed-off-by: Xin Long Link: https://patch.msgid.link/5dc95f295bdb5c3f60e880dd9aa5112dc5c071cc.1782757874.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

sctp: Unwind address notifier registration on failure

2026-06-10T15:28:40+00:00

sctp_v4_add_protocol() and sctp_v6_add_protocol() register their address notifiers before registering the SCTP protocol handlers. If protocol registration fails, the functions return without unregistering the notifiers. Unregister the notifiers on the protocol registration failure paths. Also propagate notifier registration failures instead of ignoring them. Signed-off-by: Yuho Choi Link: https://patch.msgid.link/20260608162230.46644-1-dbgh9129@gmail.com Signed-off-by: Jakub Kicinski

udp_tunnel: Pass struct sock to setup_udp_tunnel_sock().

2026-05-06T00:47:04+00:00

None of the udp_tunnel users need struct socket in their fast paths; it is only used for tunnel setup / teardown. Even setup_udp_tunnel_sock() does not need struct socket. Let's change setup_udp_tunnel_sock() to take struct sock instead of struct socket. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260502031401.3557229-3-kuniyu@google.com Signed-off-by: Jakub Kicinski

udp_tunnel: Pass struct sock to udp_tunnel_sock_release().

2026-05-06T00:47:03+00:00

None of the udp_tunnel users need struct socket in their fast paths; it is only used for tunnel setup / teardown. While the UDP tunnel interface accepts struct socket, this encourages users to store the pointer unnecessarily. This leads to extra dereferences when accessing struct sock fields (e.g., sk->sk_user_data instead of sock->sk->sk_user_data). Furthermore, these dereferences necessitate synchronize_rcu() in udp_tunnel_sock_release() to protect the fast paths from sock_orphan() setting sk->sk_socket to NULL. This overhead can be avoided if users store the struct sock pointer directly in their private structures. As a prep, let's change udp_tunnel_sock_release() to take struct sock instead of struct socket. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260502031401.3557229-2-kuniyu@google.com Signed-off-by: Jakub Kicinski

sctp: disable BH before calling udp_tunnel_xmit_skb()

2026-04-13T23:50:28+00:00

udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to tunnel xmit functions"), on the path: udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit() dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU. Without local_bh_disable(), the context may move between CPUs, which can break the inc/dec pairing. This may lead to incorrect recursion level detection and cause packets to be dropped in ip(6)_tunnel_xmit() or __dev_queue_xmit(). Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths. In my testing, after enabling the SCTP over UDP: # ip net exec ha sysctl -w net.sctp.udp_port=9899 # ip net exec ha sysctl -w net.sctp.encap_port=9899 # ip net exec hb sysctl -w net.sctp.udp_port=9899 # ip net exec hb sysctl -w net.sctp.encap_port=9899 # ip net exec ha iperf3 -s - without this patch: # ip net exec hb iperf3 -c 192.168.0.1 --sctp [ 5] 0.00-10.00 sec 37.2 MBytes 31.2 Mbits/sec sender [ 5] 0.00-10.00 sec 37.1 MBytes 31.1 Mbits/sec receiver - with this patch: # ip net exec hb iperf3 -c 192.168.0.1 --sctp [ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec sender [ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec receiver Fixes: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions") Fixes: 046c052b475e ("sctp: enable udp tunneling socks") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Link: https://patch.msgid.link/c874a8548221dcd56ff03c65ba75a74e6cf99119.1776017727.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

sctp: Remove sctp_pf.create_accept_sk().

2025-10-28T01:04:58+00:00

sctp_v[46]_create_accept_sk() are no longer used. Let's remove sctp_pf.create_accept_sk(). Signed-off-by: Kuniyuki Iwashima Acked-by: Xin Long Link: https://patch.msgid.link/20251023231751.4168390-7-kuniyu@google.com Signed-off-by: Jakub Kicinski