kernel/linux.git/net/core, branch v7.1

net: guard timestamp cmsgs to real error queue skbs

2026-06-10T01:32:08+00:00

skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb from sk_error_queue. That assumption is not true for AF_PACKET sockets: outgoing packet taps are also delivered to packet sockets with skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET instead of struct sock_exterr_skb. If such an skb is received with timestamping enabled, the generic timestamp cmsg path can read AF_PACKET control-buffer state as sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop counter overlaps opt_stats. An odd drop count makes the path emit SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear skbs this copies past the linear head and can trigger hardened usercopy or disclose adjacent heap contents. Keep skb_is_err_queue() local to net/socket.c, but make it verify that the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal receive ownership and no longer pass as error-queue skbs, while legitimate sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free ownership. Fixes: 8605330aac5a ("tcp: fix SCM_TIMESTAMPING_OPT_STATS for normal skbs") Signed-off-by: Kyle Zeng Reviewed-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260607021819.49698-1-kylebot@openai.com Signed-off-by: Jakub Kicinski

netdev: fix double-free in netdev_nl_bind_rx_doit()

2026-06-09T00:40:20+00:00

Sashiko flags that genlmsg_reply() always consumes the skb. The error path calls nlmsg_free(rsp) so we can't jump directly to it. Let's not unbind, just propagate the error to the user. This is the typical way of handling genlmsg_reply() failures. They shouldn't happen unless user does something silly like calling the kernel with an already-full rcvbuf. Reported-by: Sashiko Fixes: 170aafe35cb9 ("netdev: support binding dma-buf to netdevice") Reviewed-by: Bobby Eshleman Acked-by: Daniel Borkmann Reviewed-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski

net: add pskb_may_pull() to skb_gro_receive_list()

2026-06-09T00:20:23+00:00

skb_gro_receive_list() calls skb_pull(skb, skb_gro_offset(skb)) without first ensuring the data is in the linear area via pskb_may_pull(). When the skb arrives via napi_gro_frags(), skb_headlen can be 0 (all data in page fragments) while skb_gro_offset is non-zero (after IP+TCP header parsing). The skb_pull() then decrements skb->len by skb_gro_offset but skb->data_len stays unchanged, hitting BUG_ON(skb->len < skb->data_len) in __skb_pull(). The UDP fraglist GRO path already contains this guard at udp_offload.c:749. Adding it to skb_gro_receive_list() itself provides centralized protection for all callers (TCP, UDP, and any future protocols), and ensures the precondition of skb_pull() is satisfied before it is called. On pskb_may_pull() failure, set NAPI_GRO_CB(skb)->flush = 1 so the skb is not held as a new GRO head and is instead delivered through the normal receive path, matching the UDP handling. Fixes: 8d95dc474f85 ("net: add code for TCP fraglist GRO") Reported-by: HanQuan Reported-by: MingXuan Signed-off-by: HanQuan Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski

tcp: restrict SO_ATTACH_FILTER to priv users

2026-06-08T22:37:10+00:00

This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: Tamir Shahar Reported-by: Amit Klein Cc: Willem de Bruijn Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Eduard Zingerman Cc: Kumar Kartikeya Dwivedi Cc: Song Liu Cc: Yonghong Song Cc: Jiri Olsa Cc: John Fastabend Cc: Stanislav Fomichev Acked-by: Daniel Borkmann Reviewed-by: Willem de Bruijn Signed-off-by: Jakub Kicinski

net: Annotate sk->sk_write_space() for UDP SOCKMAP.

2026-06-02T18:44:43+00:00

UDP TX skb->destructor() is sock_wfree(), and UDP holds lock_sock() only for UDP_CORK / MSG_MORE sendmsg(). Otherwise, sk->sk_write_space() may be read locklessly while SOCKMAP rewrites sk->sk_write_space(). Let's use WRITE_ONCE() and READ_ONCE() for sk->sk_write_space(). Note that the write side is annotated by commit 2ef2b20cf4e0 ("net: annotate data-races around sk->sk_{data_ready,write_space}"). Fixes: 7b98cd42b049 ("bpf: sockmap: Add UDP support") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Jakub Sitnicki Link: https://patch.msgid.link/20260529193941.3897256-1-kuniyu@google.com Signed-off-by: Jakub Kicinski

net: skbuff: fix pskb_carve leaking zcopy pages

2026-05-29T19:55:27+00:00

When SKBFL_MANAGED_FRAG_REFS is set, frag pages are not refcounted but their lifetime is controlled by the attached ubuf_info. To make a copy of the skb_shared_info, we either should clear the flag and reference the frags, or keep the flag and have frags unreferenced. pskb_carve_inside_header() and pskb_carve_inside_nonlinear() don't follow the rule and thus can leak page references. Let's clear SKBFL_MANAGED_FRAG_REFS from the original skb to fix it. It's the simplest way to address it, but there are more performant ways to do that if it ever becomes a problem. Link: https://lore.kernel.org/all/20260523085809.26331-1-nvminh232@clc.fitus.edu.vn/ Fixes: 753f1ca4e1e50 ("net: introduce managed frags infrastructure") Reported-by: Minh Nguyen Reported-by: Willem de Bruijn Signed-off-by: Pavel Begunkov Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/1e2086aa69217d7f9c8da3d38f5be7160f1b4cd1.1779993185.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski

bpf: sockmap: fix tail fragment offset in bpf_msg_push_data

2026-05-29T19:38:35+00:00

When bpf_msg_push_data() inserts data in the middle of a scatterlist entry, it splits the original entry into a left fragment and a right fragment. The right fragment offset is page-local, but the code advances it with `start`, which is the message-global insertion point. For inserts into a non-first SG entry, this over-advances the offset and leaves the split layout inconsistent. Advance the right fragment offset by the fragment-local delta, `start - offset`, which matches the length removed from the front of the original entry. Fixes: 6fff607e2f14 ("bpf: sk_msg program helper bpf_msg_push_data") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Zhengchuan Liang Reported-by: Xin Liu Signed-off-by: Yuqi Xu Signed-off-by: Ren Wei Link: https://patch.msgid.link/8b129d10566aa3eb43f61a8f9757bcf51707d324.1779636774.git.xuyq21@lenovo.com Signed-off-by: Jakub Kicinski

Merge tag 'net-7.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-05-28T20:13:48+00:00

Pull networking fixes from Paolo Abeni: "This is again significantly bigger than the same point into the previous cycle, but at least smaller than last week. I'm not aware of any pending regression for the current cycle. Including fixes from netfilter. Current release - regressions: - netfilter: walk fib6_siblings under RCU Previous releases - regressions: - netlink: fix sending unassigned nsid after assigned one - bridge: fix sleep in atomic context in netlink path - sched: fix ethx:ingress -> ethy:egress -> ethx:ingress mirred loop - ipv4: fix net->ipv4.sysctl_local_reserved_ports UaF - eth: tun: free page on short-frame rejection in tun_xdp_one() Previous releases - always broken: - skbuff: fix missing zerocopy reference in pskb_carve helpers - handshake: drain pending requests at net namespace exit - ethtool: - rss: avoid modifying the RSS context response - module: avoid leaking a netdev ref on module flash errors - coalesce: cap profile updates at NET_DIM_PARAMS_NUM_PROFILES - netfilter: fix dst corruption in same register operation - nfc: hci: fix out-of-bounds read in HCP header parsing - ipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo() - eth: - vti: use ip6_tnl.net in vti6_changelink(). - vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()" * tag 'net-7.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (94 commits) dpll: zl3073x: make frequency monitor a per-device attribute dpll: zl3073x: use __dpll_device_change_ntf() and remove change_work dpll: export __dpll_device_change_ntf() for use under dpll_lock net/handshake: Drain pending requests at net namespace exit net/handshake: Verify file-reference balance in submit paths net/handshake: Close the submit-side sock_hold race net/handshake: hand off the pinned file reference to accept_doit net/handshake: Take a long-lived file reference at submit net/handshake: Pass negative errno through handshake_complete() nvme-tcp: store negative errno in queue->tls_err net/handshake: Use spin_lock_bh for hn_lock net: skbuff: fix missing zerocopy reference in pskb_carve helpers net: hibmcge: move dma_rmb() after dma_sync_single_for_cpu() in RX path net: hibmcge: disable Relaxed Ordering to fix RX packet corruption selftests/tc-testing: Add netem test case exercising loops selftests/tc-testing: Add mirred test cases exercising loops net/sched: act_mirred: Fix return code in early mirred redirect error paths net/sched: act_mirred: Fix blockcast recursion bypass leading to stack overflow net/sched: Fix ethx:ingress -> ethy:egress -> ethx:ingress mirred loop net/sched: fix packet loop on netem when duplicate is on ...

net: skbuff: fix missing zerocopy reference in pskb_carve helpers

2026-05-28T11:26:56+00:00

pskb_carve_inside_header() and pskb_carve_inside_nonlinear() both copy the old skb_shared_info header into a new buffer via memcpy(), which includes the destructor_arg pointer (uarg) for MSG_ZEROCOPY skbs. Neither function calls net_zcopy_get() for the new shinfo, creating an unaccounted holder: every skb_shared_info with destructor_arg set will call skb_zcopy_clear() once when freed, but the corresponding net_zcopy_get() was never called for the new copy. Repeated calls drive uarg->refcnt to zero prematurely, freeing ubuf_info_msgzc while TX skbs still hold live destructor_arg pointers. KASAN reports use-after-free on a freed ubuf_info_msgzc: BUG: KASAN: slab-use-after-free in skb_release_data+0x77b/0x810 Read of size 8 at addr ffff88801574d3e8 by task poc/220 Call Trace: skb_release_data+0x77b/0x810 kfree_skb_list_reason+0x13e/0x610 skb_release_data+0x4cd/0x810 sk_skb_reason_drop+0xf3/0x340 skb_queue_purge_reason+0x282/0x440 rds_tcp_inc_free+0x1e/0x30 rds_recvmsg+0x354/0x1780 __sys_recvmsg+0xdf/0x180 Allocated by task 219: msg_zerocopy_realloc+0x157/0x7b0 tcp_sendmsg_locked+0x2892/0x3ba0 Freed by task 219: ip_recv_error+0x74a/0xb10 tcp_recvmsg+0x475/0x530 The skb consuming the late access still referenced the same uarg via shinfo->destructor_arg copied by pskb_carve_inside_nonlinear() without a refcount bump. This has been verified to be reliably exploitable: a working proof-of-concept achieves full root privilege escalation from an unprivileged local user on a default kernel configuration. The fix follows the pattern of pskb_expand_head() which has the same memcpy/cloned structure. For pskb_carve_inside_header(), net_zcopy_get() is placed after skb_orphan_frags() succeeds, so the orphan error path needs no cleanup. For pskb_carve_inside_nonlinear(), net_zcopy_get() is placed after all failure points and just before skb_release_data(), so no error path needs cleanup at all -- matching pskb_expand_head() more closely and avoiding the need for a balancing net_zcopy_put(). Fixes: 6fa01ccd8830 ("skbuff: Add pskb_extract() helper function") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-sonnet-4-6 Signed-off-by: Minh Nguyen Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260526041240.329462-1-minhnguyen.080505@gmail.com Signed-off-by: Paolo Abeni

Merge tag 'mm-hotfixes-stable-2026-05-25-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-05-26T15:23:19+00:00

Pull misc fixes from Andrew Morton: "13 hotfixes. 9 are for MM. 9 are cc:stable and the remaining 4 address post-7.1 issues or aren't considered suitable for backporting. All patches are singletons - please see the individual changelogs for details" * tag 'mm-hotfixes-stable-2026-05-25-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: Revert "mm: introduce a new page type for page pool in page type" mm/vmalloc: do not trigger BUG() on BH disabled context MAINTAINERS, mailmap: change email for Eugen Hristev mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page kernel/fork: validate exit_signal in kernel_clone() mm: memcontrol: propagate NMI slab stats to memcg vmstats mm/damon/sysfs-schemes: delete tried region in regions_rmdirs() mm/rmap: initialize nr_pages to 1 at loop start in try_to_unmap_one zram: fix use-after-free in zram_writeback_endio memfd: deny writeable mappings when implying SEAL_WRITE ipc: limit next_id allocation to the valid ID range Revert "mm/hugetlbfs: update hugetlbfs to use mmap_prepare" MAINTAINERS: .mailmap: update after GEHC spin-off