summaryrefslogtreecommitdiff
path: root/net
AgeCommit message (Collapse)Author
2026-05-13netpoll: rename and export netpoll_zap_completion_queue()Breno Leitao
zap_completion_queue() drains the per-CPU softnet completion queue. Rename it with the netpoll_ prefix shared by the rest of the subsystem's public API, and promote it from file-static to EXPORT_SYMBOL_NS_GPL in the NETDEV_INTERNAL namespace so the upcoming netconsole-side find_skb() can call it once the function moves out. A forward declaration is added to include/linux/netpoll.h, and the old file-static forward declaration is dropped. No functional change. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-8-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netconsole: move netpoll_udp_checksum() from netpollBreno Leitao
netpoll_udp_checksum() computes the UDP checksum for netconsole's packets. Move it into drivers/net/netconsole.c as a file-static helper; drop its EXPORT_SYMBOL_GPL and remove the prototype from include/linux/netpoll.h. This was the last csum_ipv6_magic() consumer in net/core/netpoll.c, so drop the now-stale <net/ip6_checksum.h> include there. Pull it into netconsole.c so the moved code keeps building. It was also the last udp_hdr() consumer in net/core/netpoll.c. The file no longer needs anything from <net/udp.h> (the UDP socket-layer helpers); MAX_SKB_SIZE only needs struct udphdr, which is provided by the lighter <linux/udp.h>. Swap the include accordingly. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-7-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netconsole: move push_udp() from netpollBreno Leitao
push_udp() builds the UDP header (and triggers the checksum) for netconsole's UDP packets. Move it into drivers/net/netconsole.c as a file-static helper; drop its EXPORT_SYMBOL_GPL and remove the prototype from include/linux/netpoll.h. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-6-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netconsole: move push_eth() from netpollBreno Leitao
push_eth() builds the Ethernet header for netconsole's UDP packets. Move it into drivers/net/netconsole.c as a file-static helper; drop its EXPORT_SYMBOL_GPL and remove the prototype from include/linux/netpoll.h. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-5-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netconsole: move push_ipv4() from netpollBreno Leitao
push_ipv4() builds the IPv4 header for netconsole's UDP packets. Move it into drivers/net/netconsole.c as a file-static helper; drop its EXPORT_SYMBOL_GPL and remove the prototype from include/linux/netpoll.h. put_unaligned() is no longer used in net/core/netpoll.c, so drop the now-stale <linux/unaligned.h> include from there. Pull it into netconsole.c so the moved code keeps building. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-4-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netconsole: move push_ipv6() from netpollBreno Leitao
push_ipv6() builds the IPv6 header for netconsole's UDP packets. Its only caller, netpoll_send_udp(), now lives in netconsole, so the helper can move there as a file-static function. Drop its EXPORT_SYMBOL_GPL and remove the prototype from include/linux/netpoll.h. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-3-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netconsole: move netpoll_send_udp() from netpollBreno Leitao
Move netpoll_send_udp() from net/core/netpoll.c into drivers/net/netconsole.c as a static helper, drop EXPORT_SYMBOL(), and remove the prototype from include/linux/netpoll.h. netconsole was the only in-tree caller of this entry point. Every other netpoll consumer (bonding, team, vlan, bridge, macvlan, dsa) already builds its own sk_buff and hands it to netpoll_send_skb(), so the netpoll send-side interface is now skb-only. The helpers it depends on (find_skb(), push_ipv6(), push_ipv4(), push_udp(), push_eth(), netpoll_udp_checksum()) were exposed in the previous patches and stay in net/core/netpoll.c for now. Subsequent patches move each of them into netconsole one at a time and drop the corresponding EXPORT_SYMBOL_GPL. Pull <linux/ip.h>, <linux/ipv6.h> and <linux/udp.h> into netconsole.c so the moved code can name the header structures. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-2-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13netpoll: expose UDP packet builder helpers for netconsoleBreno Leitao
Promote each from file-static to EXPORT_SYMBOL_GPL and forward- declare them in include/linux/netpoll.h so netconsole can call them once netpoll_send_udp() moves out. These exports are kept until the end of the series, when al of them move into netconsole. No functional change. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260512-netconsole_split-v2-1-1191d14ad66d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13net/sched: sch_cbs: Call qdisc_reset for child qdiscJamal Hadi Salim
During a reset, CBS is not calling reset on its child qdisc, which might cause qlen/backlog accounting issues. For example, if we have CBS with a QFQ parent and a netem child with delay, we can create a scenario where the parent's qlen underflows. QFQ, specifically, uses qlen to check whether it should deference a pointer, so this scenario may cause a null-ptr deref in QFQ: [ 43.875639][ T319] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] SMP KASAN NOPTI [ 43.876124][ T319] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] [ 43.876417][ T319] CPU: 10 UID: 0 PID: 319 Comm: ping Not tainted 7.0.0-13039-ge728258debd5 #773 PREEMPT(full) [ 43.876751][ T319] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 43.876949][ T319] RIP: 0010:qfq_dequeue+0x35c/0x1650 [ 43.877123][ T319] Code: 00 fc ff df 80 3c 02 00 0f 85 17 0e 00 00 4c 8d 73 48 48 89 9d b8 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 76 0c 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b [ 43.877648][ T319] RSP: 0018:ffff8881017ef4f0 EFLAGS: 00010216 [ 43.877845][ T319] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: dffffc0000000000 [ 43.878073][ T319] RDX: 0000000000000009 RSI: 0000000c40000000 RDI: ffff88810eef02b0 [ 43.878306][ T319] RBP: ffff88810eef0000 R08: ffff88810eef0280 R09: 1ffff1102120fd63 [ 43.878523][ T319] R10: 1ffff1102120fd66 R11: 1ffff1102120fd67 R12: 0000000c40000000 [ 43.878742][ T319] R13: ffff88810eef02b8 R14: 0000000000000048 R15: 0000000020000000 [ 43.878959][ T319] FS: 00007f9c51c47c40(0000) GS:ffff88817a0be000(0000) knlGS:0000000000000000 [ 43.879214][ T319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 43.879403][ T319] CR2: 000055e69a2230a8 CR3: 000000010c07a000 CR4: 0000000000750ef0 [ 43.879621][ T319] PKRU: 55555554 [ 43.879735][ T319] Call Trace: [ 43.879844][ T319] <TASK> [ 43.879924][ T319] __qdisc_run+0x169/0x1900 [ 43.880075][ T319] ? dev_qdisc_enqueue+0x8b/0x210 [ 43.880222][ T319] __dev_queue_xmit+0x2346/0x37a0 [ 43.880376][ T319] ? register_lock_class+0x3f/0x800 [ 43.880531][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.880684][ T319] ? __pfx___dev_queue_xmit+0x10/0x10 [ 43.880834][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.880977][ T319] ? __lock_acquire+0x819/0x1df0 [ 43.881124][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.881275][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.881418][ T319] ? __asan_memcpy+0x3c/0x60 [ 43.881563][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.881708][ T319] ? eth_header+0x165/0x1a0 [ 43.881853][ T319] ? lockdep_hardirqs_on_prepare+0xdb/0x1a0 [ 43.882031][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.882174][ T319] ? neigh_resolve_output+0x3cc/0x7e0 [ 43.882325][ T319] ? srso_alias_return_thunk+0x5/0xfbef5 [ 43.882471][ T319] ip_finish_output2+0x6b6/0x1e10 Fix this by calling qdisc_reset for CBS' child qdisc. Sashiko caught an issue which could result in a null ptr deref if qdisc_create_dflt() is invoked on an unitialised cbs qdisc which is exposed by this patch. We add an early return if the qdisc is null to address this. This is a similar approach used by two other fixes[1][2]. The proper fix for this specific issue elucidated by sashiko is to remove the call to qdisc_reset when qdisc_create_dflt fails. Since the dflt qdisc isn't attached anywhere yet at that point, calling the reset callback doesn't make much sense (and as stated has been a source of two other bugs). We plan on submitting this fix in a later patch. [1] https://lore.kernel.org/netdev/20221018063201.306474-2-shaozhengchao@huawei.com/ [2] https://lore.kernel.org/netdev/20221018063201.306474-4-shaozhengchao@huawei.com/ Fixes: 585d763af09c ("net/sched: Introduce Credit Based Shaper (CBS) qdisc") Reported-by: Junyoung Jang <graypanda.inzag@gmail.com> Tested-by: Junyoung Jang <graypanda.inzag@gmail.com> Tested-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12ethtool: fix ethnl_bitmap32_not_zero() bit interval semanticsChenguang Zhao
ethnl_bitmap32_not_zero() should return true if some bit in [start, end) is set: - Fix inverted memchr_inv() sense: return true when the scan finds a non-zero byte, not when the middle words are all zero. - Return false for an empty interval (end <= start). - When end is 32-bit aligned, indices in [start, end) do not include any bits from map[end_word]; return false after earlier checks found no non-zero data. Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling") Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12net/smc: avoid NULL deref of conn->lnk in smc_msg_event tracepointXiang Mei
The smc_msg_event tracepoint class, shared by smc_tx_sendmsg and smc_rx_recvmsg, unconditionally dereferences smc->conn.lnk: __string(name, smc->conn.lnk->ibname) conn->lnk is only set for SMC-R; for SMC-D it is NULL. Other code on these paths already handles this (e.g. !conn->lnk in SMC_STAT_RMB_TX_SIZE_SMALL()). With the tracepoint enabled, the first sendmsg()/recvmsg() on an SMC-D socket crashes: Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [...] RIP: 0010:strlen+0x1e/0xa0 Call Trace: trace_event_raw_event_smc_msg_event (net/smc/smc_tracepoint.h:44) smc_rx_recvmsg (net/smc/smc_rx.c:515) smc_recvmsg (net/smc/af_smc.c:2859) __sys_recvfrom (net/socket.c:2315) __x64_sys_recvfrom (net/socket.c:2326) do_syscall_64 The faulting address 0x3e0 is offsetof(struct smc_link, ibname), confirming the NULL ->lnk deref. Enabling the tracepoint requires root, but the trigger itself is unprivileged: socket(AF_SMC, ...) has no capability check, and SMC-D negotiation needs no admin step on s390 or on x86 with the loopback ISM device loaded. Log an empty device name for SMC-D instead of dereferencing NULL. Fixes: aff3083f10bf ("net/smc: Introduce tracepoints for tx and rx msg") Reported-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Xiang Mei <xmei5@asu.edu> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoSNicolò Coccia
A logic flaw in __smc_setsockopt() allows a local unprivileged user to cause a Denial of Service (DoS) by holding the socket lock indefinitely. The function __smc_setsockopt() calls copy_from_sockptr() while holding lock_sock(sk). By passing a userfaultfd-monitored memory page (or FUSE-backed memory on systems where unprivileged userfaultfd is disabled) as the optval, an attacker can halt execution during the copy operation, keeping the lock held. Combined with asynchronous tear-down operations like shutdown(), this exhausts the kernel wq (kworkers) and triggers the hung task watchdog. [ 240.123456] INFO: task kworker/u8:2 blocked for more than 120 seconds. [ 240.123489] Call Trace: [ 240.123501] smc_shutdown+... [ 240.123512] lock_sock_nested+... This patch moves the user-space copy outside the lock_sock() critical section to prevent the issue. Fixes: a6a6fe27bab4 ("net/smc: Dynamic control handshake limitation by socket options") Signed-off-by: Nicolò Coccia <n.coccia96@gmail.com> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Tested-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12ipv6: use SKB_DROP_REASON_IP_OUTNOROUTES in inet6_csk_xmit()Eric Dumazet
Replace a bare kfree_skb() with a modern sk_skb_reason_drop() call, and provide IP_OUTNOROUTES drop reason. 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/20260511072310.1094859-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12tcp: use SKB_DROP_REASON_IP_OUTNOROUTES in tcp_v6_send_response()Eric Dumazet
Replace a bare kfree_skb() with a modern sk_skb_reason_drop() call, and provide IP_OUTNOROUTES drop reason. 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/20260511072310.1094859-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12net: constify sk_skb_reason_drop() sock parameterEric Dumazet
sk_skb_reason_drop() does not change sock parameter, make it const so that we can call it from TCP stack without a cast on a (const) listener socket. 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/20260511072310.1094859-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12rtnetlink: add RTEXT_FILTER_NAME_ONLY supportEric Dumazet
iproute2 can spend considerable amount of time in ll_init_map() or ll_link_get() to dump verbose netdev attributes, contributing to RTNL pressure. Add RTEXT_FILTER_NAME_ONLY new flag so that rtnl_fill_ifinfo() limits its output to: - struct nlmsghdr - IFLA_IFNAME - IFLA_PROP_LIST (alternate names) We can later avoid using RTNL when RTEXT_FILTER_NAME_ONLY is requested, as none of these attributes need RTNL. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260511070244.971028-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12net: atm: fix skb leak in sigd_send() default branchWei Yang
The default branch in sigd_send() calls sock_put() and returns -EINVAL without freeing the skb, while all other exit paths do so. Add the missing dev_kfree_skb() before sock_put() to fix the leak. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wei Yang <albinwyang@tencent.com> Link: https://patch.msgid.link/20260509122358.1102997-1-albin_yang@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12net: ethtool: phy: avoid NULL deref when PHY driver is unboundDavid Carlier
phydev->drv can become NULL while the phy_device is still attached to its net_device, namely after the PHY driver is unbound via sysfs: echo <mdio_id> > /sys/bus/mdio_bus/drivers/<phy_drv>/unbind phy_remove() clears phydev->drv but doesn't call phy_detach(), so the phy_device stays in the link topology xarray and ethnl_req_get_phydev() still hands it back. ETHTOOL_MSG_PHY_GET then oopses on: rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); drvname is already treated as optional by phy_reply_size(), phy_fill_reply() and phy_cleanup_data(), so just skip the allocation when there is no driver bound. Fixes: 9dd2ad5e92b9 ("net: ethtool: phy: Convert the PHY_GET command to generic phy dump") Cc: stable@vger.kernel.org # 6.13.x Signed-off-by: David Carlier <devnexen@gmail.com> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://patch.msgid.link/20260509215046.107157-1-devnexen@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-12libceph: Fix potential null-ptr-deref in decode_choose_args()Raphael Zimmer
A message of type CEPH_MSG_OSD_MAP contains an OSD map that itself contains a CRUSH map. When decoding this CRUSH map in crush_decode(), an array of max_buckets CRUSH buckets is decoded, where some indices may not refer to actual buckets and are therefore set to NULL. The received CRUSH map may optionally contain choose_args that get decoded in decode_choose_args(). When decoding a crush_choose_arg_map, a series of choose_args for different buckets is decoded, with the bucket_index being read from the incoming message. It is only checked that the bucket index does not exceed max_buckets, but not that it doesn't point to an index with a NULL bucket. If a (potentially corrupted) message contains a crush_choose_arg_map including such a bucket_index, a null pointer dereference may occur in the subsequent processing when attempting to access the bucket with the given index. This patch fixes the issue by extending the affected check. Now, it is only attempted to access the bucket if it is not NULL. Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-05-12libceph: handle rbtree insertion error in decode_choose_args()Raphael Zimmer
A message of type CEPH_MSG_OSD_MAP contains an OSD map that itself contains a CRUSH map. The received CRUSH map may optionally contain choose_args that get decoded in decode_choose_args(). In this function, num_choose_arg_maps is read from the message, and a corresponding number of crush_choose_arg_maps gets decoded afterwards. Each crush_choose_arg_map has a choose_args_index, which serves as the key when inserting it into the choose_args rbtree of the decoded crush_map. If a (potentially corrupted) message contains two crush_choose_arg_maps with the same index, the assertion in insert_choose_arg_map() triggers a kernel BUG when trying to insert the second crush_choose_arg_map. This patch fixes the issue by switching to the non-asserting rbtree insertion function and rejecting the message if the insertion fails. [ idryomov: changelog ] Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-05-12net: shaper: reject QUEUE scope handle with missing idJakub Kicinski
net_shaper_parse_handle() does not enforce that the user provides the handle ID. For NODE the ID defaults to UNSPEC for all other cases it defaults to 0. For NETDEV 0 is the only option. For QUEUE defaulting to 0 makes less intuitive sense. Specifically because the behavior should (IMHO) be the same for all cases where there may be more than one ID (QUEUE and NODE). We should either document this as intentional or reject. I picked the latter with no strong conviction. Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-11-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: enforce singleton NETDEV scope with id 0Jakub Kicinski
The NETDEV scope represents a singleton root shaper in the per-device hierarchy. All code assumes NETDEV shapers have id 0: net_shaper_default_parent() hardcodes parent->id = 0 when returning the NETDEV parent for QUEUE/NODE children, and the UAPI documentation describes NETDEV scope as "the main shaper" (singular, not plural). Make sure we reject non-0 IDs. Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-10-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: reject handle IDs exceeding internal bit-widthJakub Kicinski
net_shaper_parse_handle() reads the user-supplied handle ID via nla_get_u32(), accepting the full u32 range. However, the xarray key is built by net_shaper_handle_to_index() using FIELD_PREP(NET_SHAPER_ID_MASK, handle->id), where NET_SHAPER_ID_MASK is GENMASK(25, 0) - only 26 bits wide. FIELD_PREP silently masks off the upper bits at runtime. A user-supplied NODE id like 0x04000123 becomes id 0x123. Additionally, a user-supplied id equal to NET_SHAPER_ID_UNSPEC (0x03FFFFFF, which is NET_SHAPER_ID_MASK itself) would collide with the sentinel used internally by the group operation to signal "allocate a new NODE id". Reject user-supplied IDs >= NET_SHAPER_ID_MASK (i.e., >= 0x03FFFFFF) in the policy. Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-9-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: fix undersized reply skb allocation in GROUP commandJakub Kicinski
net_shaper_group_send_reply() writes both the NET_SHAPER_A_IFINDEX attribute (via net_shaper_fill_binding()) and the nested NET_SHAPER_A_HANDLE attribute (via net_shaper_fill_handle()), but the reply skb at the call site in net_shaper_nl_group_doit() is allocated using net_shaper_handle_size(), which only accounts for the nested handle. The allocation is therefore short by nla_total_size(sizeof(u32)) (8 bytes) for the IFINDEX attribute. In practice the slab allocator rounds up the small allocation so the bug is latent, but the size accounting is wrong and could bite if the reply grew further. Introduce net_shaper_group_reply_size() that accounts for the full reply payload and use it both at the genlmsg_new() call site and in the defensive WARN_ONCE message. Fixes: 5d5d4700e75d ("net-shapers: implement NL group operation") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-7-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: set ret to -ENOMEM when genlmsg_new() fails in group_doitJakub Kicinski
genlmsg_new() alloc failure path in net_shaper_nl_group_doit() forgets to set ret before jumping to error handling. Fixes: 5d5d4700e75d ("net-shapers: implement NL group operation") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-6-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: reject duplicate leaves in GROUP requestJakub Kicinski
net_shaper_nl_group_doit() does not deduplicate NET_SHAPER_A_LEAVES entries. When userspace supplies the same leaf handle twice, the same old-parent pointer lands twice in old_nodes[]. The cleanup loop double frees the parent. Of course the same parent may still be in old_nodes[] twice if we are moving multiple of its leaves. Note that this patch also implicitly fixes the fact that the i >= leaves_count path forgets to set ret. Fixes: 5d5d4700e75d ("net-shapers: implement NL group operation") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-4-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: fix trivial ordering issue in net_shaper_commit()Jakub Kicinski
We should update the entry before we mark it as valid. Fixes: 93954b40f6a4 ("net-shapers: implement NL set and delete operations") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-3-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: shaper: flip the polarity of the valid flagJakub Kicinski
The usual way of inserting entries which are not yet fully ready into XArray is to have a VALID flag. The shaper code has a NOT_VALID flag. Since XArray code does not let us create entries with marks already set - the creation of entries is currently not atomic. Flip the polarity of the VALID flag. This closes the tiny race in net_shaper_pre_insert() of entries being created without the NOT_VALID flag. Fixes: 93954b40f6a4 ("net-shapers: implement NL set and delete operations") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260510192904.3987113-2-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12vsock/virtio: fix empty payload in tap skb for non-linear buffersStefano Garzarella
For non-linear skbs, virtio_transport_build_skb() goes through virtio_transport_copy_nonlinear_skb() to copy the original payload in the new skb to be delivered to the vsockmon tap device. This manually initializes an iov_iter but does not set iov_iter.count. Since the iov_iter is zero-initialized, the copy length is zero and no payload is actually copied to the monitor interface, leaving data un-initialized. Fix this by removing the linear vs non-linear split and using skb_copy_datagram_iter() with iov_iter_kvec() for all cases, as vhost-vsock already does. This handles both linear and non-linear skbs, properly initializes the iov_iter, and removes the now unused virtio_transport_copy_nonlinear_skb(). While touching this code, let's also check the return value of skb_copy_datagram_iter(), even though it's unlikely to fail. Fixes: 4b0bf10eb077 ("vsock/virtio: non-linear skb handling for tap") Reported-by: Yiqi Sun <sunyiqixm@gmail.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Arseniy Krasnov <avkrasnov@rulkc.org> Link: https://patch.msgid.link/20260508164411.261440-3-sgarzare@redhat.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12vsock/virtio: fix length and offset in tap skb for split packetsStefano Garzarella
virtio_transport_build_skb() builds a new skb to be delivered to the vsockmon tap device. To build the new skb, it uses the original skb data length as payload length, but as the comment notes, the original packet stored in the skb may have been split in multiple packets, so we need to use the length in the header, which is correctly updated before the packet is delivered to the tap, and the offset for the data. This was also similar to what we did before commit 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") where we probably missed something during the skb conversion. Also update the comment above, which was left stale by the skb conversion and still mentioned a buffer pointer that no longer exists. Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Arseniy Krasnov <avkrasnov@rulkc.org> Link: https://patch.msgid.link/20260508164411.261440-2-sgarzare@redhat.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12net: hsr: fix NULL pointer dereference in hsr_get_node_data()Quan Sun
In the HSR (High-availability Seamless Redundancy) protocol, node information is maintained in the node_db. When a supervision frame is received, node->addr_B_port is updated to track the receiving port type (e.g., HSR_PT_SLAVE_B). If the underlying physical interface associated with this slave port is removed (e.g., via `ip link del`), hsr_del_port() frees the hsr_port object. However, the stale node->addr_B_port reference is kept in the node_db until the node ages out. Subsequently, if userspace queries the node status via the Netlink command HSR_C_GET_NODE_STATUS, the kernel calls hsr_get_node_data(). This function unconditionally dereferences the pointer returned by hsr_port_get_hsr(): if (node->addr_B_port != HSR_PT_NONE) { port = hsr_port_get_hsr(hsr, node->addr_B_port); *addr_b_ifindex = port->dev->ifindex; // <-- NULL deref } If the slave port has been deleted, hsr_port_get_hsr() returns NULL, resulting in a kernel panic. Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:hsr_get_node_data+0x7b6/0x9e0 Call Trace: <TASK> hsr_get_node_status+0x445/0xa40 Fix this by adding a proper NULL pointer check. If the port lookup fails due to a stale port type, gracefully treat it as if no valid port exists and assign -1 to the interface index. Steps to reproduce: 1. Create an HSR interface with two slave devices. 2. Receive a supervision frame to populate node_db with addr_B_port assigned to SLAVE_B. 3. Delete the underlying slave device B. 4. Send an HSR_C_GET_NODE_STATUS Netlink message. Fixes: c5a759117210 ("net/hsr: Use list_head (and rcu) instead of array for slave devices.") Signed-off-by: Quan Sun <2022090917019@std.uestc.edu.cn> Link: https://patch.msgid.link/20260508124636.1462346-1-2022090917019@std.uestc.edu.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-12batman-adv: tt: prevent TVLV entry number overflowSven Eckelmann
The helpers to prepare the buffers for the local and global TT based replies are trying to sum up all TT entries which can be found for each VLAN. In theory, this sum can be too big for an u16 and therefore overflow. A too small buffer would then be allocated for the TVLV. The too small buffer will be handled gracefully by batadv_tt_tvlv_generate() and is not causing a buffer overflow - just a truncated reply. But this overflow shouldn't have happened in the first and the too small buffer should never have been allocated when an overflow was detected. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann <sven@narfation.org>
2026-05-12batman-adv: tt: avoid empty VLAN responsesSven Eckelmann
The commit 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") added checks to the local (direct) TT response code. But the response can also be done indirectly by another node using the global TT state. To avoid such inconsistency states reported in the original fix, also avoid sending empty VLANs for replies from the global TT state. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann <sven@narfation.org>
2026-05-12batman-adv: tt: fix TOCTOU race for reported vlansSven Eckelmann
The local TT based TVLV is generated by first checking the number of VLANs which have at least one TT entry. A new buffer with the correct size for the VLANs is then allocated. Only then, the list of VLANs s used to fill the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock is held. But the actual number of TT entries of each VLAN can still increase during this time - just not the number of VLANs in the list. But the prefilter used in the buffer size calculation might still cause an increase of the number of VLANs which need to be stored. Simply because a VLAN might now suddenly have at least one entry when it had none in the pre-alloc check - and then needs to occupy space which was not allocated. It is better to overestimate the buffer size at the beginning and then fill the buffer only with the VLANs which are not empty. Cc: stable@kernel.org Fixes: 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") Signed-off-by: Sven Eckelmann <sven@narfation.org>
2026-05-12batman-adv: tt: fix negative last_changeset_lenSven Eckelmann
batadv_piv_tt::last_changeset_len len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_my_tt_response(), last_changeset_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_local_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_my_tt_response(). Cc: stable@kernel.org Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann <sven@narfation.org>
2026-05-12batman-adv: tt: fix negative tt_buff_lenSven Eckelmann
batadv_orig_node::tt_buff_len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_other_tt_response(), tt_buff_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_other_tt_response(). Cc: stable@kernel.org Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann <sven@narfation.org>
2026-05-12batman-adv: tt: reject oversized local TVLV buffersSven Eckelmann
The commit 3a359bf5c61d ("batman-adv: reject oversized global TT response buffers") added a check to ensure that a global return buffer size can be stored in an u16. The same buffer handling also exists for the local data buffer but was not touched. A similar check should be also be in place for the local TVLV buffer. It doesn't have the similar attack surface because it is only generated from locally discovered MAC addresses but the dynamic nature could still cause temporarily to large buffers. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann <sven@narfation.org>
2026-05-11net: ethtool: fix missing closing paren in rings_reply_size()Tao Cui
sizeof(u32) on the _RINGS_CQE_SIZE line is missing its closing parenthesis, causing nla_total_size() to absorb the subsequent _TX_PUSH and _RX_PUSH entries. The resulting size estimate happens to be numerically identical due to NLA alignment, so not treating this as a real fix. But the nesting is wrong and misleading. Signed-off-by: Tao Cui <cuitao@kylinos.cn> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260508125412.189804-1-cuitao@kylinos.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: mq_prio: no longer acquire qdisc spinlocks in ↵Eric Dumazet
mqprio_dump_class_stats() Prepare mqprio_dump_class_stats() for RTNL avoidance. Use RCU instead of RTNL, and no longer acquire each children spinlock. As a bonus we no longer have to release/acquire d->lock. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: mq_prio: no longer acquire qdisc spinlocks in mqprio_dump()Eric Dumazet
Prepare mqprio_dump() for RTNL avoidance. Use RCU instead of RTNL, and no longer acquire each children spinlock. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: mq: no longer acquire qdisc spinlocks in dump operationsEric Dumazet
Prepare mq_dump_common() for RTNL avoidance. Use RCU instead of RTNL, and no longer acquire each children spinlock. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: add const qualifiers to gnet_stats helpersEric Dumazet
In preparation of lockless qdisc dumps, add const qualifiers to: - gnet_stats_add_basic() - gnet_stats_copy_basic() - gnet_stats_copy_basic_hw() - gnet_stats_copy_queue() - gnet_stats_read_basic() - ___gnet_stats_copy_basic() - qdisc_qstats_copy() Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: add qdisc_qlen_lockless() helperEric Dumazet
Used in contexts were qdisc spinlock is not held. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: annotate data-races around sch->qstats.backlogEric Dumazet
Add qstats_backlog_sub() and qstats_backlog_add() helpers and use them instead of open-coding them. These helpers use WRITE_ONCE() to prevent store-tearing. Also use WRITE_ONCE() in fq_reset() and qdisc_reset() when sch->qstats.backlog is cleared. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: add qdisc_qlen_inc() and qdisc_qlen_dec()Eric Dumazet
Helpers to increment or decrement sch->q.qlen, with appropriate WRITE_ONCE() to prevent store tearing. Add other WRITE_ONCE() when sch->q.qlen is changed. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: add READ_ONCE() in gnet_stats_add_queue[_cpu]Eric Dumazet
Stats are read locklessly, add READ_ONCE() to prevent load-tearing. Write side will be handled in separate patches. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: dualpi2: initialize timer earlier in dualpi2_init()Davide Caratti
'pi2_timer' needs to be initialized in all error paths of dualpi2_init(): otherwise, a failure in qdisc_create_dflt() causes the following crash in dualpi2_destroy(): # tc qdisc add dev crash0 handle 1: root dualpi2 BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 4 UID: 0 PID: 471 Comm: tc Tainted: G E 7.1.0-rc1-virtme #2 PREEMPT(full) Tainted: [E]=UNSIGNED_MODULE Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 RIP: 0010:hrtimer_active+0x39/0x60 Code: f9 eb 23 0f b6 41 38 3c 01 0f 87 87 64 c0 ff 83 e0 01 75 33 48 39 4a 50 74 28 44 3b 42 10 75 06 48 3b 51 30 74 21 48 8b 51 30 <44> 8b 42 10 41 f6 c0 01 74 cf f3 90 44 8b 42 10 41 f6 c0 01 74 c3 RSP: 0018:ffffd0db80b93620 EFLAGS: 00010282 RAX: ffffffffc0400320 RBX: ffff8cf24a4c86b8 RCX: ffff8cf24a4c86b8 RDX: 0000000000000000 RSI: ffff8cf2429c2ab0 RDI: ffff8cf24a4c86b8 RBP: 00000000fffffff4 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000001 R11: ffff8cf24a39c500 R12: ffff8cf24822c000 R13: ffffd0db80b936c0 R14: ffffffffc02cf360 R15: 00000000ffffffff FS: 00007fbc01706580(0000) GS:ffff8cf2dc759000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000008e02003 CR4: 0000000000172ef0 Call Trace: <TASK> hrtimer_cancel+0x15/0x40 dualpi2_destroy+0x20/0x40 [sch_dualpi2] qdisc_create+0x230/0x570 tc_modify_qdisc+0x716/0xc10 rtnetlink_rcv_msg+0x188/0x780 netlink_rcv_skb+0xcd/0x150 netlink_unicast+0x1ba/0x290 netlink_sendmsg+0x242/0x4d0 ____sys_sendmsg+0x39e/0x3e0 ___sys_sendmsg+0xe1/0x130 __sys_sendmsg+0xad/0x110 do_syscall_64+0x14f/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbc0188b08e Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa RSP: 002b:00007fff593260e0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbc0188b08e RDX: 0000000000000000 RSI: 00007fff59326190 RDI: 0000000000000003 RBP: 00007fff593260f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055f06124f260 R13: 0000000069fca043 R14: 000055f061255640 R15: 000055f06124d3f8 </TASK> Modules linked in: sch_dualpi2(E) CR2: 0000000000000010 [1] https://lore.kernel.org/netdev/2e78e01c504c633ebdff18d041833cf2e079a3a4.1607020450.git.dcaratti@redhat.com/ [2] https://lore.kernel.org/netdev/20200725201707.16909-1-xiyou.wangcong@gmail.com/ v2: - rebased on top of latest net.git Fixes: 320d031ad6e4 ("sched: Struct definition and parsing of dualpi2 qdisc") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/1faca91179702b31da5d87653e1e036543e32722.1778259798.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11mptcp: pm: in-kernel: increase endpoints limitMatthieu Baerts (NGI0)
The endpoints are managed in a list which was limited to 8 entries. This limit can be too small in some cases: by having the same limit as the number of subflows, it might not allow creating all expected subflows when having a mix of v4 and v6 addresses that can all use MPTCP on v4/v6 only networks. While increasing the limit above the new subflows one, why not using the technical limit: 255. Indeed, the endpoint will each have an ID that will be used on the wire, limited to u8, and the ID 0 is reserved to the initial subflow. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20260508-net-next-mptcp-pm-inc-limits-v1-4-c84e3fdf9b6a@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11mptcp: pm: kernel: allow flushing more than 8 endpointsMatthieu Baerts (NGI0)
The mptcp_rm_list structure contains an array of IDs of 8 entries: to be able to send a RM_ADDR with 8 IDs. This limitation was OK so far because there could maximum 8 endpoints. But this is going to change in the next commit. To cope with that, if one of the arrays is full, the iteration stops, the lists are processed, then the iteration continues where it previously stopped. Note that if there are many endpoints to remove, and multiple RM_ADDR to send, it might be more likely that some of these RM_ADDRs are dropped or lost. This is a known limitation: RM_ADDR are not retransmitted in MPTCPv1. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20260508-net-next-mptcp-pm-inc-limits-v1-3-c84e3fdf9b6a@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11mptcp: pm: in-kernel: increase all limits to 64Matthieu Baerts (NGI0)
This means switching the maximum from 8 to 64 for the number of subflows and accepted ADD_ADDR. The previous limit of 8 subflows makes sense in most cases. Using more subflows will very likely *not* improve the situation, and could even decrease the performances. But there are no technical limitations nor performance impact to raise this limit, so let's do it: this will allow people with very specific use-cases, and researchers to easily create more subflows, and measure the performance impact by themselves. The theoretical limit is 255 -- the ID is written in a u8 on the wire -- but 64 is more than enough. With so many subflows, it will be costly to iterate over all of them when operations are done in bottom half. Note that the in-kernel PM will continue to create subflows in reply to ADD_ADDR with a single batch of maximum 8 subflows. Same when adding new "subflow" endpoints with the fullmesh flag. Increasing those batch limits would have a memory impact, and it looks fine not to cover these cases with larger batches for the moment. If more is needed later, the position of the last subflow from the list could be remembered, and the list iteration could continue later. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/434 Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20260508-net-next-mptcp-pm-inc-limits-v1-2-c84e3fdf9b6a@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>