linux/net, branch v6.15

Merge tag 'ipsec-2025-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2025-05-22T09:49:53Z

Steffen Klassert says: ==================== pull request (net): ipsec 2025-05-21 1) Fix some missing kfree_skb in the error paths of espintcp. From Sabrina Dubroca. 2) Fix a reference leak in espintcp. From Sabrina Dubroca. 3) Fix UDP GRO handling for ESPINUDP. From Tobias Brunner. 4) Fix ipcomp truesize computation on the receive path. From Sabrina Dubroca. 5) Sanitize marks before policy/state insertation. From Paul Chaignon. * tag 'ipsec-2025-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: Sanitize marks before insert xfrm: ipcomp: fix truesize computation on receive xfrm: Fix UDP GRO handling for some corner cases espintcp: remove encap socket caching to avoid reference leak espintcp: fix skb leaks ==================== Link: https://patch.msgid.link/20250521054348.4057269-1-steffen.klassert@secunet.com Signed-off-by: Paolo Abeni

net/tipc: fix slab-use-after-free Read in tipc_aead_encrypt_done

2025-05-22T09:33:12Z

Syzbot reported a slab-use-after-free with the following call trace: ================================================================== BUG: KASAN: slab-use-after-free in tipc_aead_encrypt_done+0x4bd/0x510 net/tipc/crypto.c:840 Read of size 8 at addr ffff88807a733000 by task kworker/1:0/25 Call Trace: kasan_report+0xd9/0x110 mm/kasan/report.c:601 tipc_aead_encrypt_done+0x4bd/0x510 net/tipc/crypto.c:840 crypto_request_complete include/crypto/algapi.h:266 aead_request_complete include/crypto/internal/aead.h:85 cryptd_aead_crypt+0x3b8/0x750 crypto/cryptd.c:772 crypto_request_complete include/crypto/algapi.h:266 cryptd_queue_worker+0x131/0x200 crypto/cryptd.c:181 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 Allocated by task 8355: kzalloc_noprof include/linux/slab.h:778 tipc_crypto_start+0xcc/0x9e0 net/tipc/crypto.c:1466 tipc_init_net+0x2dd/0x430 net/tipc/core.c:72 ops_init+0xb9/0x650 net/core/net_namespace.c:139 setup_net+0x435/0xb40 net/core/net_namespace.c:343 copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x419/0x970 kernel/fork.c:3323 __do_sys_unshare kernel/fork.c:3394 Freed by task 63: kfree+0x12a/0x3b0 mm/slub.c:4557 tipc_crypto_stop+0x23c/0x500 net/tipc/crypto.c:1539 tipc_exit_net+0x8c/0x110 net/tipc/core.c:119 ops_exit_list+0xb0/0x180 net/core/net_namespace.c:173 cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 After freed the tipc_crypto tx by delete namespace, tipc_aead_encrypt_done may still visit it in cryptd_queue_worker workqueue. I reproduce this issue by: ip netns add ns1 ip link add veth1 type veth peer name veth2 ip link set veth1 netns ns1 ip netns exec ns1 tipc bearer enable media eth dev veth1 ip netns exec ns1 tipc node set key this_is_a_master_key master ip netns exec ns1 tipc bearer disable media eth dev veth1 ip netns del ns1 The key of reproduction is that, simd_aead_encrypt is interrupted, leading to crypto_simd_usable() return false. Thus, the cryptd_queue_worker is triggered, and the tipc_crypto tx will be visited. tipc_disc_timeout tipc_bearer_xmit_skb tipc_crypto_xmit tipc_aead_encrypt crypto_aead_encrypt // encrypt() simd_aead_encrypt // crypto_simd_usable() is false child = &ctx->cryptd_tfm->base; simd_aead_encrypt crypto_aead_encrypt // encrypt() cryptd_aead_encrypt_enqueue cryptd_aead_enqueue cryptd_enqueue_request // trigger cryptd_queue_worker queue_work_on(smp_processor_id(), cryptd_wq, &cpu_queue->work) Fix this by holding net reference count before encrypt. Reported-by: syzbot+55c12726619ff85ce1f6@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=55c12726619ff85ce1f6 Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Signed-off-by: Wang Liang Link: https://patch.msgid.link/20250520101404.1341730-1-wangliang74@huawei.com Signed-off-by: Paolo Abeni

sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()

2025-05-22T09:16:44Z

When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list, causing further consequences like use-after-free. This patch fixes the bug by moving the increment of sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures that queue length and backlog are always accurate when packet drops or dequeues are triggered during the peek. Fixes: 12d0ad3be9c3 ("net/sched/sch_hfsc.c: handle corner cases where head may change invalidating calculated deadline") Reported-by: Mingi Cho Signed-off-by: Cong Wang Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250518222038.58538-2-xiyou.wangcong@gmail.com Reviewed-by: Jamal Hadi Salim Signed-off-by: Paolo Abeni

xsk: Bring back busy polling support in XDP_COPY

2025-05-21T09:28:23Z

Commit 5ef44b3cb43b ("xsk: Bring back busy polling support") fixed the busy polling support in xsk for XDP_ZEROCOPY after it was broken in commit 86e25f40aa1e ("net: napi: Add napi_config"). The busy polling support with XDP_COPY remained broken since the napi_id setup in xsk_rcv_check was removed. Bring back the setup of napi_id for XDP_COPY so socket level SO_BUSYPOLL can be used to poll the underlying napi. Do the setup of napi_id for XDP_COPY in xsk_bind, as it is done currently for XDP_ZEROCOPY. The setup of napi_id for XDP_COPY in xsk_bind is safe because xsk_rcv_check checks that the rx queue at which the packet arrives is equal to the queue_id that was supplied in bind. This is done for both XDP_COPY and XDP_ZEROCOPY mode. Tested using AF_XDP support in virtio-net by running the xsk_rr AF_XDP benchmarking tool shared here: https://lore.kernel.org/all/20250320163523.3501305-1-skhawaja@google.com/T/ Enabled socket busy polling using following commands in qemu, ``` sudo ethtool -L eth0 combined 1 echo 400 | sudo tee /proc/sys/net/core/busy_read echo 100 | sudo tee /sys/class/net/eth0/napi_defer_hard_irqs echo 15000 | sudo tee /sys/class/net/eth0/gro_flush_timeout ``` Fixes: 5ef44b3cb43b ("xsk: Bring back busy polling support") Signed-off-by: Samiullah Khawaja Reviewed-by: Willem de Bruijn Acked-by: Stanislav Fomichev Signed-off-by: David S. Miller

can: bcm: add missing rcu read protection for procfs content

2025-05-19T14:58:19Z

When the procfs content is generated for a bcm_op which is in the process to be removed the procfs output might show unreliable data (UAF). As the removal of bcm_op's is already implemented with rcu handling this patch adds the missing rcu_read_lock() and makes sure the list entries are properly removed under rcu protection. Fixes: f1b4e32aca08 ("can: bcm: use call_rcu() instead of costly synchronize_rcu()") Reported-by: Anderson Nascimento Suggested-by: Anderson Nascimento Tested-by: Anderson Nascimento Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20250519125027.11900-2-socketcan@hartkopp.net Cc: stable@vger.kernel.org # >= 5.4 Signed-off-by: Marc Kleine-Budde

can: bcm: add locking for bcm_op runtime updates

2025-05-19T14:58:12Z

The CAN broadcast manager (CAN BCM) can send a sequence of CAN frames via hrtimer. The content and also the length of the sequence can be changed resp reduced at runtime where the 'currframe' counter is then set to zero. Although this appeared to be a safe operation the updates of 'currframe' can be triggered from user space and hrtimer context in bcm_can_tx(). Anderson Nascimento created a proof of concept that triggered a KASAN slab-out-of-bounds read access which can be prevented with a spin_lock_bh. At the rework of bcm_can_tx() the 'count' variable has been moved into the protected section as this variable can be modified from both contexts too. Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol") Reported-by: Anderson Nascimento Tested-by: Anderson Nascimento Reviewed-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20250519125027.11900-1-socketcan@hartkopp.net Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde

llc: fix data loss when reading from a socket in llc_ui_recvmsg()

2025-05-19T11:12:54Z

For SOCK_STREAM sockets, if user buffer size (len) is less than skb size (skb->len), the remaining data from skb will be lost after calling kfree_skb(). To fix this, move the statement for partial reading above skb deletion. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) Fixes: 30a584d944fb ("[LLX]: SOCK_DGRAM interface fixes") Cc: stable@vger.kernel.org Signed-off-by: Ilia Gavrilov Signed-off-by: David S. Miller

mr: consolidate the ipmr_can_free_table() checks.

2025-05-17T00:53:48Z

Guoyu Yin reported a splat in the ipmr netns cleanup path: WARNING: CPU: 2 PID: 14564 at net/ipv4/ipmr.c:440 ipmr_free_table net/ipv4/ipmr.c:440 [inline] WARNING: CPU: 2 PID: 14564 at net/ipv4/ipmr.c:440 ipmr_rules_exit+0x135/0x1c0 net/ipv4/ipmr.c:361 Modules linked in: CPU: 2 UID: 0 PID: 14564 Comm: syz.4.838 Not tainted 6.14.0 #1 Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:ipmr_free_table net/ipv4/ipmr.c:440 [inline] RIP: 0010:ipmr_rules_exit+0x135/0x1c0 net/ipv4/ipmr.c:361 Code: ff df 48 c1 ea 03 80 3c 02 00 75 7d 48 c7 83 60 05 00 00 00 00 00 00 5b 5d 41 5c 41 5d 41 5e e9 71 67 7f 00 e8 4c 2d 8a fd 90 <0f> 0b 90 eb 93 e8 41 2d 8a fd 0f b6 2d 80 54 ea 01 31 ff 89 ee e8 RSP: 0018:ffff888109547c58 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff888108c12dc0 RCX: ffffffff83e09868 RDX: ffff8881022b3300 RSI: ffffffff83e098d4 RDI: 0000000000000005 RBP: ffff888104288000 R08: 0000000000000000 R09: ffffed10211825c9 R10: 0000000000000001 R11: ffff88801816c4a0 R12: 0000000000000001 R13: ffff888108c13320 R14: ffff888108c12dc0 R15: fffffbfff0b74058 FS: 00007f84f39316c0(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f84f3930f98 CR3: 0000000113b56000 CR4: 0000000000350ef0 Call Trace: ipmr_net_exit_batch+0x50/0x90 net/ipv4/ipmr.c:3160 ops_exit_list+0x10c/0x160 net/core/net_namespace.c:177 setup_net+0x47d/0x8e0 net/core/net_namespace.c:394 copy_net_ns+0x25d/0x410 net/core/net_namespace.c:516 create_new_namespaces+0x3f6/0xaf0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc3/0x180 kernel/nsproxy.c:228 ksys_unshare+0x78d/0x9a0 kernel/fork.c:3342 __do_sys_unshare kernel/fork.c:3413 [inline] __se_sys_unshare kernel/fork.c:3411 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3411 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xa6/0x1a0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f84f532cc29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f84f3931038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f84f5615fa0 RCX: 00007f84f532cc29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000400 RBP: 00007f84f53fba18 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f84f5615fa0 R15: 00007fff51c5f328 The running kernel has CONFIG_IP_MROUTE_MULTIPLE_TABLES disabled, and the sanity check for such build is still too loose. Address the issue consolidating the relevant sanity check in a single helper regardless of the kernel configuration. Also share it between the ipv4 and ipv6 code. Reported-by: Guoyu Yin Fixes: 50b94204446e ("ipmr: tune the ipmr_can_free_table() checks.") Signed-off-by: Paolo Abeni Link: https://patch.msgid.link/372dc261e1bf12742276e1b984fc5a071b7fc5a8.1747321903.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski

bridge: netfilter: Fix forwarding of fragmented packets

2025-05-16T23:02:06Z

When netfilter defrag hooks are loaded (due to the presence of conntrack rules, for example), fragmented packets entering the bridge will be defragged by the bridge's pre-routing hook (br_nf_pre_routing() -> ipv4_conntrack_defrag()). Later on, in the bridge's post-routing hook, the defragged packet will be fragmented again. If the size of the largest fragment is larger than what the kernel has determined as the destination MTU (using ip_skb_dst_mtu()), the defragged packet will be dropped. Before commit ac6627a28dbf ("net: ipv4: Consolidate ipv4_mtu and ip_dst_mtu_maybe_forward"), ip_skb_dst_mtu() would return dst_mtu() as the destination MTU. Assuming the dst entry attached to the packet is the bridge's fake rtable one, this would simply be the bridge's MTU (see fake_mtu()). However, after above mentioned commit, ip_skb_dst_mtu() ends up returning the route's MTU stored in the dst entry's metrics. Ideally, in case the dst entry is the bridge's fake rtable one, this should be the bridge's MTU as the bridge takes care of updating this metric when its MTU changes (see br_change_mtu()). Unfortunately, the last operation is a no-op given the metrics attached to the fake rtable entry are marked as read-only. Therefore, ip_skb_dst_mtu() ends up returning 1500 (the initial MTU value) and defragged packets are dropped during fragmentation when dealing with large fragments and high MTU (e.g., 9k). Fix by moving the fake rtable entry's metrics to be per-bridge (in a similar fashion to the fake rtable entry itself) and marking them as writable, thereby allowing MTU changes to be reflected. Fixes: 62fa8a846d7d ("net: Implement read-only protection and COW'ing of metrics.") Fixes: 33eb9873a283 ("bridge: initialize fake_rtable metrics") Reported-by: Venkat Venkatsubra Closes: https://lore.kernel.org/netdev/PH0PR10MB4504888284FF4CBA648197D0ACB82@PH0PR10MB4504.namprd10.prod.outlook.com/ Tested-by: Venkat Venkatsubra Signed-off-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20250515084848.727706-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski

net: dsa: microchip: linearize skb for tail-tagging switches

2025-05-16T23:00:17Z

The pointer arithmentic for accessing the tail tag only works for linear skbs. For nonlinear skbs, it reads uninitialized memory inside the skb headroom, essentially randomizing the tag. I have observed it gets set to 6 most of the time. Example where ksz9477_rcv thinks that the packet from port 1 comes from port 6 (which does not exist for the ksz9896 that's in use), dropping the packet. Debug prints added by me (not included in this patch): [ 256.645337] ksz9477_rcv:323 tag0=6 [ 256.645349] skb len=47 headroom=78 headlen=0 tailroom=0 mac=(64,14) mac_len=14 net=(78,0) trans=78 shinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0)) csum(0x0 start=0 offset=0 ip_summed=0 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x00f8 pkttype=1 iif=3 priority=0x0 mark=0x0 alloc_cpu=0 vlan_all=0x0 encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0) [ 256.645377] dev name=end1 feat=0x0002e10200114bb3 [ 256.645386] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645395] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645403] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645411] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645420] skb headroom: 00000040: ff ff ff ff ff ff 00 1c 19 f2 e2 db 08 06 [ 256.645428] skb frag: 00000000: 00 01 08 00 06 04 00 01 00 1c 19 f2 e2 db 0a 02 [ 256.645436] skb frag: 00000010: 00 83 00 00 00 00 00 00 0a 02 a0 2f 00 00 00 00 [ 256.645444] skb frag: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 [ 256.645452] ksz_common_rcv:92 dsa_conduit_find_user returned NULL Call skb_linearize before trying to access the tag. This patch fixes ksz9477_rcv which is used by the ksz9896 I have at hand, and also applies the same fix to ksz8795_rcv which seems to have the same problem. Signed-off-by: Jakob Unterwurzacher CC: stable@vger.kernel.org Fixes: 016e43a26bab ("net: dsa: ksz: Add KSZ8795 tag code") Fixes: 8b8010fb7876 ("dsa: add support for Microchip KSZ tail tagging") Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20250515072920.2313014-1-jakob.unterwurzacher@cherry.de Signed-off-by: Jakub Kicinski