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2026-03-12Bluetooth: LE L2CAP: Disconnect if sum of payload sizes exceed SDUChristian Eggers1-0/+1
Core 6.0, Vol 3, Part A, 3.4.3: "... If the sum of the payload sizes for the K-frames exceeds the specified SDU length, the receiver shall disconnect the channel." This fixes L2CAP/LE/CFC/BV-27-C (running together with 'l2test -r -P 0x0027 -V le_public'). Fixes: aac23bf63659 ("Bluetooth: Implement LE L2CAP reassembly") Signed-off-by: Christian Eggers <ceggers@arri.de> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-03-12Bluetooth: LE L2CAP: Disconnect if received packet's SDU exceeds IMTUChristian Eggers1-3/+7
Core 6.0, Vol 3, Part A, 3.4.3: "If the SDU length field value exceeds the receiver's MTU, the receiver shall disconnect the channel..." This fixes L2CAP/LE/CFC/BV-26-C (running together with 'l2test -r -P 0x0027 -V le_public -I 100'). Fixes: aac23bf63659 ("Bluetooth: Implement LE L2CAP reassembly") Signed-off-by: Christian Eggers <ceggers@arri.de> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-03-12net: prevent NULL deref in ip[6]tunnel_xmit()Eric Dumazet1-4/+6
Blamed commit missed that both functions can be called with dev == NULL. Also add unlikely() hints for these conditions that only fuzzers can hit. Fixes: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions") Signed-off-by: Eric Dumazet <edumazet@google.com> CC: Weiming Shi <bestswngs@gmail.com> Link: https://patch.msgid.link/20260312043908.2790803-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-12tcp: add tcp_release_cb_cond() helperEric Dumazet2-11/+8
Majority of tcp_release_cb() calls do nothing at all. Provide tcp_release_cb_cond() helper so that release_sock() can avoid these calls. Also hint the compiler that __release_sock() and wake_up() are rarely called. $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-77 (-77) Function old new delta release_sock 258 181 -77 Total: Before=25235790, After=25235713, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260310124451.2280968-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-12vsock: add G2H fallback for CIDs not owned by H2G transportAlexander Graf2-5/+37
When no H2G transport is loaded, vsock currently routes all CIDs to the G2H transport (commit 65b422d9b61b ("vsock: forward all packets to the host when no H2G is registered"). Extend that existing behavior: when an H2G transport is loaded but does not claim a given CID, the connection falls back to G2H in the same way. This matters in environments like Nitro Enclaves, where an instance may run nested VMs via vhost-vsock (H2G) while also needing to reach sibling enclaves at higher CIDs through virtio-vsock-pci (G2H). With the old code, any CID > 2 was unconditionally routed to H2G when vhost was loaded, making those enclaves unreachable without setting VMADDR_FLAG_TO_HOST explicitly on every connect. Requiring every application to set VMADDR_FLAG_TO_HOST creates friction: tools like socat, iperf, and others would all need to learn about it. The flag was introduced 6 years ago and I am still not aware of any tool that supports it. Even if there was support, it would be cumbersome to use. The most natural experience is a single CID address space where H2G only wins for CIDs it actually owns, and everything else falls through to G2H, extending the behavior that already exists when H2G is absent. To give user space at least a hint that the kernel applied this logic, automatically set the VMADDR_FLAG_TO_HOST on the remote address so it can determine the path taken via getpeername(). Add a per-network namespace sysctl net.vsock.g2h_fallback (default 1). At 0 it forces strict routing: H2G always wins for CID > VMADDR_CID_HOST, or ENODEV if H2G is not loaded. Signed-off-by: Alexander Graf <graf@amazon.com> Tested-by: syzbot@syzkaller.appspotmail.com Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260304230027.59857-1-graf@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-12xfrm: avoid RCU warnings around the per-netns netlink socketSabrina Dubroca1-8/+17
net->xfrm.nlsk is used in 2 types of contexts: - fully under RCU, with rcu_read_lock + rcu_dereference and a NULL check - in the netlink handlers, with requests coming from a userspace socket In the 2nd case, net->xfrm.nlsk is guaranteed to stay non-NULL and the object is alive, since we can't enter the netns destruction path while the user socket holds a reference on the netns. After adding the __rcu annotation to netns_xfrm.nlsk (which silences sparse warnings in the RCU users and __net_init code), we need to tell sparse that the 2nd case is safe. Add a helper for that. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: add rcu_access_pointer to silence sparse warning for xfrm_input_afinfoSabrina Dubroca1-1/+4
xfrm_input_afinfo is __rcu, we should use rcu_access_pointer to avoid a sparse warning: net/xfrm/xfrm_input.c:78:21: error: incompatible types in comparison expression (different address spaces): net/xfrm/xfrm_input.c:78:21: struct xfrm_input_afinfo const [noderef] __rcu * net/xfrm/xfrm_input.c:78:21: struct xfrm_input_afinfo const * Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: policy: silence sparse warning in xfrm_policy_unregister_afinfoSabrina Dubroca1-1/+1
xfrm_policy_afinfo is __rcu, use rcu_access_pointer to silence: net/xfrm/xfrm_policy.c:4152:43: error: incompatible types in comparison expression (different address spaces): net/xfrm/xfrm_policy.c:4152:43: struct xfrm_policy_afinfo const [noderef] __rcu * net/xfrm/xfrm_policy.c:4152:43: struct xfrm_policy_afinfo const * Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: policy: fix sparse warnings in xfrm_policy_{init,fini}Sabrina Dubroca1-4/+4
In xfrm_policy_init: add rcu_assign_pointer to fix warning: net/xfrm/xfrm_policy.c:4238:29: warning: incorrect type in assignment (different address spaces) net/xfrm/xfrm_policy.c:4238:29: expected struct hlist_head [noderef] __rcu *table net/xfrm/xfrm_policy.c:4238:29: got struct hlist_head * add rcu_dereference_protected to silence warning: net/xfrm/xfrm_policy.c:4265:36: warning: incorrect type in argument 1 (different address spaces) net/xfrm/xfrm_policy.c:4265:36: expected struct hlist_head *n net/xfrm/xfrm_policy.c:4265:36: got struct hlist_head [noderef] __rcu *table The netns is being created, no concurrent access is possible yet. In xfrm_policy_fini, net is going away, there shouldn't be any concurrent changes to the hashtables, so we can use rcu_dereference_protected to silence warnings: net/xfrm/xfrm_policy.c:4291:17: warning: incorrect type in argument 1 (different address spaces) net/xfrm/xfrm_policy.c:4291:17: expected struct hlist_head const *h net/xfrm/xfrm_policy.c:4291:17: got struct hlist_head [noderef] __rcu *table net/xfrm/xfrm_policy.c:4292:36: warning: incorrect type in argument 1 (different address spaces) net/xfrm/xfrm_policy.c:4292:36: expected struct hlist_head *n net/xfrm/xfrm_policy.c:4292:36: got struct hlist_head [noderef] __rcu *table Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: state: silence sparse warnings during netns exitSabrina Dubroca1-8/+10
Silence sparse warnings in xfrm_state_fini: net/xfrm/xfrm_state.c:3327:9: warning: incorrect type in argument 1 (different address spaces) net/xfrm/xfrm_state.c:3327:9: expected struct hlist_head const *h net/xfrm/xfrm_state.c:3327:9: got struct hlist_head [noderef] __rcu *state_byseq Add xfrm_state_deref_netexit() to wrap those calls. The netns is going away, we don't have to worry about the state_by* pointers being changed behind our backs. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: remove rcu/state_hold from xfrm_state_lookup_spi_protoSabrina Dubroca1-9/+2
xfrm_state_lookup_spi_proto is called under xfrm_state_lock by xfrm_alloc_spi, no need to take a reference on the state and pretend to be under RCU. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: state: add xfrm_state_deref_prot to state_by* walk under lockSabrina Dubroca1-11/+11
We're under xfrm_state_lock for all those walks, we can use xfrm_state_deref_prot to silence sparse warnings such as: net/xfrm/xfrm_state.c:933:17: warning: dereference of noderef expression Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: state: fix sparse warnings around XFRM_STATE_INSERTSabrina Dubroca1-11/+19
We're under xfrm_state_lock in all those cases, use xfrm_state_deref_prot(state_by*) to avoid sparse warnings: net/xfrm/xfrm_state.c:2597:25: warning: cast removes address space '__rcu' of expression net/xfrm/xfrm_state.c:2597:25: warning: incorrect type in argument 2 (different address spaces) net/xfrm/xfrm_state.c:2597:25: expected struct hlist_head *h net/xfrm/xfrm_state.c:2597:25: got struct hlist_head [noderef] __rcu * Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: state: fix sparse warnings in xfrm_state_initSabrina Dubroca1-12/+20
Use rcu_assign_pointer, and tmp variables for freeing on the error path without accessing net->xfrm.state_by*. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-12xfrm: state: fix sparse warnings on xfrm_state_hold_rcuSabrina Dubroca1-1/+1
In all callers, x is not an __rcu pointer. We can drop the annotation to avoid sparse warnings: net/xfrm/xfrm_state.c:58:39: warning: incorrect type in argument 1 (different address spaces) net/xfrm/xfrm_state.c:58:39: expected struct refcount_struct [usertype] *r net/xfrm/xfrm_state.c:58:39: got struct refcount_struct [noderef] __rcu * net/xfrm/xfrm_state.c:1166:42: warning: incorrect type in argument 1 (different address spaces) net/xfrm/xfrm_state.c:1166:42: expected struct xfrm_state [noderef] __rcu *x net/xfrm/xfrm_state.c:1166:42: got struct xfrm_state *[assigned] x (repeated for each caller) Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-03-11net: Convert move_addr_to_user() to scoped user accessChristophe Leroy (CS GROUP)1-17/+11
move_addr_to_user() is a critical functions that was converted to masked user access by commit 1fb0e471611d ("net: remove one stac/clac pair from move_addr_to_user()") Convert it to scoped user access to simplify the code. Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/36d7f2e7f504d620c1b88526b25ebc89e3cb61d9.1773142315.git.chleroy@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11tcp: use WRITE_ONCE() for tsoffset in tcp_v6_connect()Wesley Atwell1-1/+1
Commit dd23c9f1e8d5 ("tcp: annotate data-races around tp->tsoffset") updated do_tcp_getsockopt() to read tp->tsoffset with READ_ONCE() for TCP_TIMESTAMP because another CPU may change it concurrently. tcp_v6_connect() still stores tp->tsoffset with a plain write. That store runs under lock_sock() via inet_stream_connect(), but the socket lock does not serialize a concurrent getsockopt(TCP_TIMESTAMP) from another task sharing the socket. Use WRITE_ONCE() for the tcp_v6_connect() store so the connect-time writer matches the lockless TCP_TIMESTAMP reader. This also makes the IPv6 path consistent with tcp_v4_connect(). Signed-off-by: Wesley Atwell <atwellwea@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@shopee.com> Link: https://patch.msgid.link/20260310012604.145661-1-atwellwea@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11Merge tag 'nf-26-03-10' of ↵Jakub Kicinski8-14/+23
https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Florian Westphal says: ==================== netfilter: updates for net Due to large volume of backlogged patches its unlikely I will make the 2nd planned PR this week, so several legit fixes will be pushed back to next week. Sorry for the inconvenience but I am out of ideas and alternatives. 1) syzbot managed to add/remove devices to a flowtable, due to a bug in the flowtable netdevice notifier this gets us a double-add and eventually UaF when device is removed again (we only expect one entry, duplicate remains past net_device end-of-life). From Phil Sutter, bug added in 6.16. 2) Yiming Qian reports another nf_tables transaction handling bug: in some cases error unwind misses to undo certain set elements, resulting in refcount underflow and use-after-free, bug added in 6.4. 3) Jenny Guanni Qu found out-of-bounds read in pipapo set type. While the value is never used, it still rightfully triggers KASAN splats. Bug exists since this set type was added in 5.6. 4) a few x_tables modules contain copypastry tcp option parsing code which can read 1 byte past the option area. This bug is ancient, fix from David Dull. 5) nfnetlink_queue leaks kernel memory if userspace provides bad NFQA_VLAN/NFQA_L2HDR attributes. From Hyunwoo Kim, bug stems from from 4.7 days. 6) nfnetlink_cthelper has incorrect loop restart logic which may result in reading one pointer past end of array. From 3.6 days, fix also from Hyunwoo Kim. 7) xt_IDLETIMER v0 extension must reject working with timers added by revision v1, else we get list corruption. Bug added in v5.7. From Yifan Wu, Juefei Pu and Yuan Tan via Xin Lu. * tag 'nf-26-03-10' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels netfilter: nfnetlink_cthelper: fix OOB read in nfnl_cthelper_dump_table() netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path netfilter: x_tables: guard option walkers against 1-byte tail reads netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop() netfilter: nf_tables: always walk all pending catchall elements netfilter: nf_tables: Fix for duplicate device in netdev hooks ==================== Link: https://patch.msgid.link/20260310132050.630-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11neighbour: restore protocol != 0 check in pneigh updateSabrina Dubroca1-1/+2
Prior to commit dc2a27e524ac ("neighbour: Update pneigh_entry in pneigh_create()."), a pneigh's protocol was updated only when the value of the NDA_PROTOCOL attribute was non-0. While moving the code, that check was removed. This is a small change of user-visible behavior, and inconsistent with the (non-proxy) neighbour behavior. Fixes: dc2a27e524ac ("neighbour: Update pneigh_entry in pneigh_create().") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/38c61de1bb032871a886aff9b9b52fe1cdd4cada.1772894876.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11tipc: fix divide-by-zero in tipc_sk_filter_connect()Mehul Rao1-0/+2
A user can set conn_timeout to any value via setsockopt(TIPC_CONN_TIMEOUT), including values less than 4. When a SYN is rejected with TIPC_ERR_OVERLOAD and the retry path in tipc_sk_filter_connect() executes: delay %= (tsk->conn_timeout / 4); If conn_timeout is in the range [0, 3], the integer division yields 0, and the modulo operation triggers a divide-by-zero exception, causing a kernel oops/panic. Fix this by clamping conn_timeout to a minimum of 4 at the point of use in tipc_sk_filter_connect(). Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 119 Comm: poc-F144 Not tainted 7.0.0-rc2+ RIP: 0010:tipc_sk_filter_rcv (net/tipc/socket.c:2236 net/tipc/socket.c:2362) Call Trace: tipc_sk_backlog_rcv (include/linux/instrumented.h:82 include/linux/atomic/atomic-instrumented.h:32 include/net/sock.h:2357 net/tipc/socket.c:2406) __release_sock (include/net/sock.h:1185 net/core/sock.c:3213) release_sock (net/core/sock.c:3797) tipc_connect (net/tipc/socket.c:2570) __sys_connect (include/linux/file.h:62 include/linux/file.h:83 net/socket.c:2098) Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket") Cc: stable@vger.kernel.org Signed-off-by: Mehul Rao <mehulrao@gmail.com> Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech> Link: https://patch.msgid.link/20260310170730.28841-1-mehulrao@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11bpf: bpf_out_neigh_v6: Fix nd_tbl NULL dereference when IPv6 is disabledRicardo B. Marlière1-0/+3
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. If bpf_redirect_neigh() is called with explicit AF_INET6 nexthop parameters, __bpf_redirect_neigh_v6() can skip the IPv6 FIB lookup and call bpf_out_neigh_v6() directly. bpf_out_neigh_v6() then calls ip_neigh_gw6(), which uses ipv6_stub->nd_tbl. BUG: kernel NULL pointer dereference, address: 0000000000000248 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:skb_do_redirect+0x44f/0xf40 Call Trace: <TASK> ? srso_alias_return_thunk+0x5/0xfbef5 ? __tcf_classify.constprop.0+0x83/0x160 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcf_classify+0x2b/0x50 ? srso_alias_return_thunk+0x5/0xfbef5 ? tc_run+0xb8/0x120 ? srso_alias_return_thunk+0x5/0xfbef5 __dev_queue_xmit+0x6fa/0x1000 ? srso_alias_return_thunk+0x5/0xfbef5 packet_sendmsg+0x10da/0x1700 ? srso_alias_return_thunk+0x5/0xfbef5 __sys_sendto+0x1f3/0x220 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x101/0xf80 ? exc_page_fault+0x6e/0x170 ? srso_alias_return_thunk+0x5/0xfbef5 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Fix this by adding an early check in bpf_out_neigh_v6(). If IPv6 is disabled, drop the packet before neighbor lookup. Suggested-by: Fernando Fernandez Mancera <fmancera@suse.de> Fixes: ba452c9e996d ("bpf: Fix bpf_redirect_neigh helper api to support supplying nexthop") Signed-off-by: Ricardo B. Marlière <rbm@suse.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/20260307-net-nd_tbl_fixes-v4-4-e2677e85628c@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11bpf: bpf_out_neigh_v4: Fix nd_tbl NULL dereference when IPv6 is disabledRicardo B. Marlière1-0/+4
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. If bpf_redirect_neigh() is called from tc with an explicit nexthop of nh_family == AF_INET6, bpf_out_neigh_v4() takes the AF_INET6 branch and calls ip_neigh_gw6(), which relies on ipv6_stub->nd_tbl. BUG: kernel NULL pointer dereference, address: 0000000000000248 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:skb_do_redirect+0xb93/0xf00 Call Trace: <TASK> ? srso_alias_return_thunk+0x5/0xfbef5 ? __tcf_classify.constprop.0+0x83/0x160 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcf_classify+0x2b/0x50 ? srso_alias_return_thunk+0x5/0xfbef5 ? tc_run+0xb8/0x120 ? srso_alias_return_thunk+0x5/0xfbef5 __dev_queue_xmit+0x6fa/0x1000 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? alloc_skb_with_frags+0x58/0x200 packet_sendmsg+0x10da/0x1700 ? srso_alias_return_thunk+0x5/0xfbef5 __sys_sendto+0x1f3/0x220 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x101/0xf80 ? exc_page_fault+0x6e/0x170 ? srso_alias_return_thunk+0x5/0xfbef5 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Fix this by adding an early check in the AF_INET6 branch of bpf_out_neigh_v4(). If IPv6 is disabled, unlock RCU and drop the packet. Suggested-by: Fernando Fernandez Mancera <fmancera@suse.de> Fixes: ba452c9e996d ("bpf: Fix bpf_redirect_neigh helper api to support supplying nexthop") Signed-off-by: Ricardo B. Marlière <rbm@suse.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/20260307-net-nd_tbl_fixes-v4-3-e2677e85628c@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11ipv6: move the disable_ipv6_mod knob to core codeJakub Kicinski2-8/+6
From: Jakub Kicinski <kuba@kernel.org> Make sure disable_ipv6_mod itself is not part of the IPv6 module, in case core code wants to refer to it. We will remove support for IPv6=m soon, this change helps make fixes we commit before that less messy. Link: https://patch.msgid.link/20260307-net-nd_tbl_fixes-v4-1-e2677e85628c@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-11libceph: Fix potential out-of-bounds access in ceph_handle_auth_reply()Raphael Zimmer1-2/+4
This patch fixes an out-of-bounds access in ceph_handle_auth_reply() that can be triggered by a message of type CEPH_MSG_AUTH_REPLY. In ceph_handle_auth_reply(), the value of the payload_len field of such a message is stored in a variable of type int. A value greater than INT_MAX leads to an integer overflow and is interpreted as a negative value. This leads to decrementing the pointer address by this value and subsequently accessing it because ceph_decode_need() only checks that the memory access does not exceed the end address of the allocation. This patch fixes the issue by changing the data type of payload_len to u32. Additionally, the data type of result_msg_len is changed to u32, as it is also a variable holding a non-negative length. Also, an additional layer of sanity checks is introduced, ensuring that directly after reading it from the message, payload_len and result_msg_len are not greater than the overall segment length. BUG: KASAN: slab-out-of-bounds in ceph_handle_auth_reply+0x642/0x7a0 [libceph] Read of size 4 at addr ffff88811404df14 by task kworker/20:1/262 CPU: 20 UID: 0 PID: 262 Comm: kworker/20:1 Not tainted 6.19.2 #5 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: ceph-msgr ceph_con_workfn [libceph] Call Trace: <TASK> dump_stack_lvl+0x76/0xa0 print_report+0xd1/0x620 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? kasan_complete_mode_report_info+0x72/0x210 kasan_report+0xe7/0x130 ? ceph_handle_auth_reply+0x642/0x7a0 [libceph] ? ceph_handle_auth_reply+0x642/0x7a0 [libceph] __asan_report_load_n_noabort+0xf/0x20 ceph_handle_auth_reply+0x642/0x7a0 [libceph] mon_dispatch+0x973/0x23d0 [libceph] ? apparmor_socket_recvmsg+0x6b/0xa0 ? __pfx_mon_dispatch+0x10/0x10 [libceph] ? __kasan_check_write+0x14/0x30i ? mutex_unlock+0x7f/0xd0 ? __pfx_mutex_unlock+0x10/0x10 ? __pfx_do_recvmsg+0x10/0x10 [libceph] ceph_con_process_message+0x1f1/0x650 [libceph] process_message+0x1e/0x450 [libceph] ceph_con_v2_try_read+0x2e48/0x6c80 [libceph] ? __pfx_ceph_con_v2_try_read+0x10/0x10 [libceph] ? save_fpregs_to_fpstate+0xb0/0x230 ? raw_spin_rq_unlock+0x17/0xa0 ? finish_task_switch.isra.0+0x13b/0x760 ? __switch_to+0x385/0xda0 ? __kasan_check_write+0x14/0x30 ? mutex_lock+0x8d/0xe0 ? __pfx_mutex_lock+0x10/0x10 ceph_con_workfn+0x248/0x10c0 [libceph] process_one_work+0x629/0xf80 ? __kasan_check_write+0x14/0x30 worker_thread+0x87f/0x1570 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? __pfx_try_to_wake_up+0x10/0x10 ? kasan_print_address_stack_frame+0x1f7/0x280 ? __pfx_worker_thread+0x10/0x10 kthread+0x396/0x830 ? __pfx__raw_spin_lock_irq+0x10/0x10 ? __pfx_kthread+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? recalc_sigpending+0x180/0x210 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3f7/0x610 ? __pfx_ret_from_fork+0x10/0x10 ? __switch_to+0x385/0xda0 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> [ idryomov: replace if statements with ceph_decode_need() for payload_len and result_msg_len ] Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-03-11libceph: Use u32 for non-negative values in ceph_monmap_decode()Raphael Zimmer1-3/+3
This patch fixes unnecessary implicit conversions that change signedness of blob_len and num_mon in ceph_monmap_decode(). Currently blob_len and num_mon are (signed) int variables. They are used to hold values that are always non-negative and get assigned in ceph_decode_32_safe(), which is meant to assign u32 values. Both variables are subsequently used as unsigned values, and the value of num_mon is further assigned to monmap->num_mon, which is of type u32. Therefore, both variables should be of type u32. This is especially relevant for num_mon. If the value read from the incoming message is very large, it is interpreted as a negative value, and the check for num_mon > CEPH_MAX_MON does not catch it. This leads to the attempt to allocate a very large chunk of memory for monmap, which will most likely fail. In this case, an unnecessary attempt to allocate memory is performed, and -ENOMEM is returned instead of -EINVAL. Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-03-10net: sched: cls_u32: Avoid memcpy() false-positive warning in u32_init_knode()Jiayuan Chen1-1/+4
Syzbot reported a warning in u32_init_knode() [1]. Similar to commit 7cba18332e36 ("net: sched: cls_u32: Avoid memcpy() false-positive warning") which addressed the same issue in u32_change(), use unsafe_memcpy() in u32_init_knode() to work around the compiler's inability to see into composite flexible array structs. This silences the false-positive reported by syzbot: memcpy: detected field-spanning write (size 32) of single field "&new->sel" at net/sched/cls_u32.c:855 (size 16) Since the memory is correctly allocated with kzalloc_flex() using s->nkeys, this is purely a false positive and does not need a Fixes tag. [1] https://syzkaller.appspot.com/bug?extid=d5ace703ed883df56e42 Reported-by: syzbot+d5ace703ed883df56e42@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69a811b9.a70a0220.b118c.0019.GAE@google.com/T/ Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com> Link: https://patch.msgid.link/20260309123917.402183-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10net-shapers: don't free reply skb after genlmsg_reply()Paul Moses1-9/+2
genlmsg_reply() hands the reply skb to netlink, and netlink_unicast() consumes it on all return paths, whether the skb is queued successfully or freed on an error path. net_shaper_nl_get_doit() and net_shaper_nl_cap_get_doit() currently jump to free_msg after genlmsg_reply() fails and call nlmsg_free(msg), which can hit the same skb twice. Return the genlmsg_reply() error directly and keep free_msg only for pre-reply failures. Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation") Fixes: 553ea9f1efd6 ("net: shaper: implement introspection support") Cc: stable@vger.kernel.org Signed-off-by: Paul Moses <p@1g4.org> Link: https://patch.msgid.link/20260309173450.538026-2-p@1g4.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10page_pool: store detach_time as ktime_t to avoid false-negativesJakub Kicinski1-2/+2
While testing other changes in vng I noticed that nl_netdev.page_pool_check flakes. This never happens in real CI. Turns out vng may boot and get to that test in less than a second. page_pool_detached() records the detach time in seconds, so if vng is fast enough detach time is set to 0. Other code treats 0 as "not detached". detach_time is only used to report the state to the user, so it's not a huge deal in practice but let's fix it. Store the raw ktime_t (nanoseconds) instead. A nanosecond value of 0 is practically impossible. Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Fixes: 69cb4952b6f6 ("net: page_pool: report when page pool was destroyed") Link: https://patch.msgid.link/20260310003907.3540019-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10inet: add ip_local_port_step_width sysctl to improve port usage distributionFernando Fernandez Mancera2-3/+32
With the current port selection algorithm, ports after a reserved port range or long time used port are used more often than others [1]. This causes an uneven port usage distribution. This combines with cloud environments blocking connections between the application server and the database server if there was a previous connection with the same source port, leading to connectivity problems between applications on cloud environments. The real issue here is that these firewalls cannot cope with standards-compliant port reuse. This is a workaround for such situations and an improvement on the distribution of ports selected. The proposed solution is to implement a variant of RFC 6056 Algorithm 5. The step size is selected randomly on every connect() call ensuring it is a coprime with respect to the size of the range of ports we want to scan. This way, we can ensure that all ports within the range are scanned before returning an error. To enable this algorithm, the user must configure the new sysctl option "net.ipv4.ip_local_port_step_width". In addition, on graphs generated we can observe that the distribution of source ports is more even with the proposed approach. [2] [1] https://0xffsoftware.com/port_graph_current_alg.html [2] https://0xffsoftware.com/port_graph_random_step_alg.html Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260309023946.5473-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labelsYuan Tan1-0/+6
IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type. Fixes: 68983a354a65 ("netfilter: xtables: Add snapshot of hardidletimer target") Co-developed-by: Yifan Wu <yifanwucs@gmail.com> Signed-off-by: Yifan Wu <yifanwucs@gmail.com> Co-developed-by: Juefei Pu <tomapufckgml@gmail.com> Signed-off-by: Juefei Pu <tomapufckgml@gmail.com> Signed-off-by: Yuan Tan <tanyuan98@outlook.com> Signed-off-by: Xin Liu <dstsmallbird@foxmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10netfilter: nfnetlink_cthelper: fix OOB read in nfnl_cthelper_dump_table()Hyunwoo Kim1-4/+4
nfnl_cthelper_dump_table() has a 'goto restart' that jumps to a label inside the for loop body. When the "last" helper saved in cb->args[1] is deleted between dump rounds, every entry fails the (cur != last) check, so cb->args[1] is never cleared. The for loop finishes with cb->args[0] == nf_ct_helper_hsize, and the 'goto restart' jumps back into the loop body bypassing the bounds check, causing an 8-byte out-of-bounds read on nf_ct_helper_hash[nf_ct_helper_hsize]. The 'goto restart' block was meant to re-traverse the current bucket when "last" is no longer found, but it was placed after the for loop instead of inside it. Move the block into the for loop body so that the restart only occurs while cb->args[0] is still within bounds. BUG: KASAN: slab-out-of-bounds in nfnl_cthelper_dump_table+0x9f/0x1b0 Read of size 8 at addr ffff888104ca3000 by task poc_cthelper/131 Call Trace: nfnl_cthelper_dump_table+0x9f/0x1b0 netlink_dump+0x333/0x880 netlink_recvmsg+0x3e2/0x4b0 sock_recvmsg+0xde/0xf0 __sys_recvfrom+0x150/0x200 __x64_sys_recvfrom+0x76/0x90 do_syscall_64+0xc3/0x6e0 Allocated by task 1: __kvmalloc_node_noprof+0x21b/0x700 nf_ct_alloc_hashtable+0x65/0xd0 nf_conntrack_helper_init+0x21/0x60 nf_conntrack_init_start+0x18d/0x300 nf_conntrack_standalone_init+0x12/0xc0 Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure") Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10netfilter: nfnetlink_queue: fix entry leak in bridge verdict error pathHyunwoo Kim1-1/+3
nfqnl_recv_verdict() calls find_dequeue_entry() to remove the queue entry from the queue data structures, taking ownership of the entry. For PF_BRIDGE packets, it then calls nfqa_parse_bridge() to parse VLAN attributes. If nfqa_parse_bridge() returns an error (e.g. NFQA_VLAN present but NFQA_VLAN_TCI missing), the function returns immediately without freeing the dequeued entry or its sk_buff. This leaks the nf_queue_entry, its associated sk_buff, and all held references (net_device refcounts, struct net refcount). Repeated triggering exhausts kernel memory. Fix this by dropping the entry via nfqnl_reinject() with NF_DROP verdict on the error path, consistent with other error handling in this file. Fixes: 8d45ff22f1b4 ("netfilter: bridge: nf queue verdict to use NFQA_VLAN and NFQA_L2HDR") Reviewed-by: David Dull <monderasdor@gmail.com> Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10netfilter: x_tables: guard option walkers against 1-byte tail readsDavid Dull2-4/+6
When the last byte of options is a non-single-byte option kind, walkers that advance with i += op[i + 1] ? : 1 can read op[i + 1] past the end of the option area. Add an explicit i == optlen - 1 check before dereferencing op[i + 1] in xt_tcpudp and xt_dccp option walkers. Fixes: 2e4e6a17af35 ("[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables") Signed-off-by: David Dull <monderasdor@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()Jenny Guanni Qu1-1/+2
pipapo_drop() passes rulemap[i + 1].n to pipapo_unmap() as the to_offset argument on every iteration, including the last one where i == m->field_count - 1. This reads one element past the end of the stack-allocated rulemap array (declared as rulemap[NFT_PIPAPO_MAX_FIELDS] with NFT_PIPAPO_MAX_FIELDS == 16). Although pipapo_unmap() returns early when is_last is true without using the to_offset value, the argument is evaluated at the call site before the function body executes, making this a genuine out-of-bounds stack read confirmed by KASAN: BUG: KASAN: stack-out-of-bounds in pipapo_drop+0x50c/0x57c [nf_tables] Read of size 4 at addr ffff8000810e71a4 This frame has 1 object: [32, 160) 'rulemap' The buggy address is at offset 164 -- exactly 4 bytes past the end of the rulemap array. Pass 0 instead of rulemap[i + 1].n on the last iteration to avoid the out-of-bounds read. Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Signed-off-by: Jenny Guanni Qu <qguanni@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10netfilter: nf_tables: always walk all pending catchall elementsFlorian Westphal1-2/+0
During transaction processing we might have more than one catchall element: 1 live catchall element and 1 pending element that is coming as part of the new batch. If the map holding the catchall elements is also going away, its required to toggle all catchall elements and not just the first viable candidate. Otherwise, we get: WARNING: ./include/net/netfilter/nf_tables.h:1281 at nft_data_release+0xb7/0xe0 [nf_tables], CPU#2: nft/1404 RIP: 0010:nft_data_release+0xb7/0xe0 [nf_tables] [..] __nft_set_elem_destroy+0x106/0x380 [nf_tables] nf_tables_abort_release+0x348/0x8d0 [nf_tables] nf_tables_abort+0xcf2/0x3ac0 [nf_tables] nfnetlink_rcv_batch+0x9c9/0x20e0 [..] Fixes: 628bd3e49cba ("netfilter: nf_tables: drop map element references from preparation phase") Reported-by: Yiming Qian <yimingqian591@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10netfilter: nf_tables: Fix for duplicate device in netdev hooksPhil Sutter2-2/+2
When handling NETDEV_REGISTER notification, duplicate device registration must be avoided since the device may have been added by nft_netdev_hook_alloc() already when creating the hook. Suggested-by: Florian Westphal <fw@strlen.de> Reported-by: syzbot+bb9127e278fa198e110c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=bb9127e278fa198e110c Fixes: a331b78a5525 ("netfilter: nf_tables: Respect NETDEV_REGISTER events") Tested-by: Helen Koike <koike@igalia.com> Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-10net: export netif_open for self_test usageMike Marciniszyn (Meta)1-0/+1
dev_open() already is exported, but drivers which use the netdev instance lock need to use netif_open() instead. netif_close() is also already exported [1] so this completes the pairing. This export is required for the following fbnic self tests to avoid calling ndo_stop() and ndo_open() in favor of the more appropriate netif_open() and netif_close() that notifies any listeners that the interface went down to test and is now coming back up. Link: https://patch.msgid.link/20250309215851.2003708-1-sdf@fomichev.me [1] Signed-off-by: Mike Marciniszyn (Meta) <mike.marciniszyn@gmail.com> Link: https://patch.msgid.link/20260307105847.1438-2-mike.marciniszyn@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-10net: add xmit recursion limit to tunnel xmit functionsWeiming Shi2-35/+13
Tunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own recursion limit. When a bond device in broadcast mode has GRE tap interfaces as slaves, and those GRE tunnels route back through the bond, multicast/broadcast traffic triggers infinite recursion between bond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing kernel stack overflow. The existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not sufficient because tunnel recursion involves route lookups and full IP output, consuming much more stack per level. Use a lower limit of 4 (IP_TUNNEL_RECURSION_LIMIT) to prevent overflow. Add recursion detection using dev_xmit_recursion helpers directly in iptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel paths including UDP encapsulated tunnels (VXLAN, Geneve, etc.). Move dev_xmit_recursion helpers from net/core/dev.h to public header include/linux/netdevice.h so they can be used by tunnel code. BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160 Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11 Workqueue: mld mld_ifc_work Call Trace: <TASK> __build_flow_key.constprop.0 (net/ipv4/route.c:515) ip_rt_update_pmtu (net/ipv4/route.c:1073) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84) ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) ip_finish_output2 (net/ipv4/ip_output.c:237) ip_output (net/ipv4/ip_output.c:438) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) ip_finish_output2 (net/ipv4/ip_output.c:237) ip_output (net/ipv4/ip_output.c:438) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86) ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) mld_sendpack mld_ifc_work process_one_work worker_thread </TASK> Fixes: 745e20f1b626 ("net: add a recursion limit in xmit path") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Link: https://patch.msgid.link/20260306160133.3852900-2-bestswngs@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-10libceph: reject preamble if control segment is emptyIlya Dryomov1-9/+8
While head_onwire_len() has a branch to handle ctrl_len == 0 case, prepare_read_control() always sets up a kvec for the CRC meaning that a non-empty control segment is effectively assumed. All frames that clients deal with meet that assumption, so let's make it official and treat the preamble with an empty control segment as malformed. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Alex Markuze <amarkuze@redhat.com>
2026-03-10libceph: admit message frames only in CEPH_CON_S_OPEN stateIlya Dryomov1-0/+5
Similar checks are performed for all control frames, but an early check for message frames was missing. process_message() is already set up to terminate the loop in case the state changes while con->ops->dispatch() handler is being executed. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
2026-03-10libceph: prevent potential out-of-bounds reads in process_message_header()Ilya Dryomov1-1/+8
If the message frame is (maliciously) corrupted in a way that the length of the control segment ends up being less than the size of the message header or a different frame is made to look like a message frame, out-of-bounds reads may ensue in process_message_header(). Perform an explicit bounds check before decoding the message header. Cc: stable@vger.kernel.org Reported-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
2026-03-10mctp: route: hold key->lock in mctp_flow_prepare_output()Chengfeng Ye1-4/+7
mctp_flow_prepare_output() checks key->dev and may call mctp_dev_set_key(), but it does not hold key->lock while doing so. mctp_dev_set_key() and mctp_dev_release_key() are annotated with __must_hold(&key->lock), so key->dev access is intended to be serialized by key->lock. The mctp_sendmsg() transmit path reaches mctp_flow_prepare_output() via mctp_local_output() -> mctp_dst_output() without holding key->lock, so the check-and-set sequence is racy. Example interleaving: CPU0 CPU1 ---- ---- mctp_flow_prepare_output(key, devA) if (!key->dev) // sees NULL mctp_flow_prepare_output( key, devB) if (!key->dev) // still NULL mctp_dev_set_key(devB, key) mctp_dev_hold(devB) key->dev = devB mctp_dev_set_key(devA, key) mctp_dev_hold(devA) key->dev = devA // overwrites devB Now both devA and devB references were acquired, but only the final key->dev value is tracked for release. One reference can be lost, causing a resource leak as mctp_dev_release_key() would only decrease the reference on one dev. Fix by taking key->lock around the key->dev check and mctp_dev_set_key() call. Fixes: 67737c457281 ("mctp: Pass flow data & flow release events to drivers") Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> Link: https://patch.msgid.link/20260306031402.857224-1-dg573847474@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-09tcp: inline tcp_chrono_start()Eric Dumazet1-24/+0
tcp_chrono_start() is small enough, and used in TCP sendmsg() fast path (from tcp_skb_entail()). Note clang is already inlining it from functions in tcp_output.c. Inlining it improves performance and reduces bloat : $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/2 grow/shrink: 1/0 up/down: 1/-84 (-83) Function old new delta tcp_skb_entail 280 281 +1 __pfx_tcp_chrono_start 16 - -16 tcp_chrono_start 68 - -68 Total: Before=25192434, After=25192351, chg -0.00% Note that tcp_chrono_stop() is too big. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20260308123549.2924460-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09net/sched: refine indirect call mitigation in tc_wrapper.hEric Dumazet1-1/+2
Some modern cpus disable X86_FEATURE_RETPOLINE feature, even if a direct call can still be beneficial. Even when IBRS is present, an indirect call is more expensive than a direct one: Direct Calls: Compilers can perform powerful optimizations like inlining, where the function body is directly inserted at the call site, eliminating call overhead entirely. Indirect Calls: Inlining is much harder, if not impossible, because the compiler doesn't know the target function at compile time. Techniques like Indirect Call Promotion can help by using profile-guided optimization to turn frequently taken indirect calls into conditional direct calls, but they still add complexity and potential overhead compared to a truly direct call. In this patch, I split tc_skip_wrapper in two different static keys, one for tc_act() (tc_skip_wrapper_act) and one for tc_classify() (tc_skip_wrapper_cls). Then I enable the tc_skip_wrapper_cls only if the count of builtin classifiers is above one. I enable tc_skip_wrapper_act only it the count of builtin actions is above one. In our production kernels, we only have CONFIG_NET_CLS_BPF=y and CONFIG_NET_ACT_BPF=y. Other are modules or are not compiled. Tested on AMD Turin cpus, cls_bpf_classify() cost went from 1% down to 0.18 %, and FDO will be able to inline it in tcf_classify() for further gains. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Link: https://patch.msgid.link/20260307133601.3863071-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09ppp: simplify input error handlingQingfang Deng1-1/+1
Currently, ppp_input_error() indicates an error by allocating a 0-length skb and calling ppp_do_recv(). It takes an error code argument, which is stored in skb->cb, but not used by ppp_receive_frame(). Simplify the error handling by removing the unused parameter and the unnecessary skb allocation. Instead, call ppp_receive_error() directly from ppp_input_error() under the recv lock, and the length check in ppp_receive_frame() can be removed. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09net/sched: use rtnl_kfree_skbs() in pfifo_fast_reset()Eric Dumazet1-1/+1
rtnl_kfree_skbs() reduces RTNL and qdisc spinlock hold time. skbs are freed later after RTNL has been released. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260306133154.678730-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09net/sched: do not reset queues in graft operationsEric Dumazet8-16/+20
Following typical script is extremely disruptive, because each graft operation calls dev_deactivate() which resets all the queues of the device. QPARAM="limit 100000 flow_limit 1000 buckets 4096" TXQS=64 for ETH in eth1 do tc qd del dev $ETH root 2>/dev/null tc qd add dev $ETH root handle 1: mq for i in `seq 1 $TXQS` do slot=$( printf %x $(( i )) ) tc qd add dev $ETH parent 1:$slot fq $QPARAM done done One can add "ip link set dev $ETH down/up" to reduce the disruption time: QPARAM="limit 100000 flow_limit 1000 buckets 4096" TXQS=64 for ETH in eth1 do ip link set dev $ETH down tc qd del dev $ETH root 2>/dev/null tc qd add dev $ETH root handle 1: mq for i in `seq 1 $TXQS` do slot=$( printf %x $(( i )) ) tc qd add dev $ETH parent 1:$slot fq $QPARAM done ip link set dev $ETH up done Or we can add a @reset_needed flag to dev_deactivate() and dev_deactivate_many(). This flag is set to true at device dismantle or linkwatch_do_dev(), and to false for graft operations. In the future, we might only stop one queue instead of the whole device, ie call dev_deactivate_queue() instead of dev_deactivate(). I think the problem (quadratic behavior) was added in commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") but this does not look serious enough to deserve risky backports. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Link: https://patch.msgid.link/20260307163430.470644-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09tcp: avoid dst->ops->check() call in tcp_v{4,6}_do_rcv()Eric Dumazet2-2/+2
If incoming skb dst matches the socket cached one, there is no need to call again dst->ops->check(). Network layer already validated the skb dst for us, usually from tcp_v{4,6}_early_demux(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260306154322.1086539-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09tcp: move tcp_v4_early_demux() to net/ipv4/ip_input.cEric Dumazet2-38/+39
tcp_v4_early_demux() has a single caller : ip_rcv_finish_core(). Move it to net/ipv4/ip_input.c and mark it static, for possible compiler/linker optimizations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260306131130.654991-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09tcp: remove unused hash_size from struct tcp_out_optionsKeita Morisaki1-1/+0
hash_size is declared but never read. The MD5 path always uses a fixed size of 16, and the TCP-AO path uses tcp_ao_maclen(). This closes a 7-byte hole and reduces the struct size from 96 to 88 bytes. Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Keita Morisaki <kmta1236@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260307051619.51685-1-kmta1236@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>