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7 daysvsock/vmci: fix sk_ack_backlog leak on failed handshakeRaf Dickson
When vmci_transport_recv_connecting_server() returns an error, vmci_transport_recv_listen() calls vsock_remove_pending() but never calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented permanently. Repeated handshake failures (malformed packets, queue pair alloc failure, event subscribe failure) cause sk_ack_backlog to climb toward sk_max_ack_backlog. Once it reaches the limit the listener permanently refuses all new connections with -ECONNREFUSED, a silent denial of service requiring a process restart to recover. The two existing sk_acceptq_removed() calls in af_vsock.c do not cover this path: line 764 checks vsock_is_pending() which returns false after vsock_remove_pending(), and line 1889 is only reached on successful accept(). Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on the error path. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Cc: stable@vger.kernel.org Signed-off-by: Raf Dickson <rafdog35@gmail.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260526104356.469928-1-rafdog35@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
13 daysvsock/virtio: bind uarg before filling zerocopy skbJingguo Tan
virtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg before entering the send loop, but virtio_transport_alloc_skb() still fills the skb before it inherits that uarg. When fixed-buffer vectored zerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach managed frags and return -EMSGSIZE. The rollback path call kfree_skb() to free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so skb_release_data() falls through to ordinary frag unref. Pass the uarg into virtio_transport_alloc_skb() and bind it immediately before virtio_transport_fill_skb(). This keeps control or no-payload skbs untouched while ensuring success and rollback share one lifetime rule. Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support") Signed-off-by: Lin Ma <malin89@huawei.com> Signed-off-by: Rongzhen Cui <cuirongzhen@huawei.com> Signed-off-by: Jingguo Tan <tanjingguo@huawei.com> Acked-by: Arseniy Krasnov <avkrasnov@salutedevices.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260527023301.1075581-1-malin89@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-22vsock/virtio: fix skb overhead overflow on 32-bit buildsStefano Garzarella
On 32-bit architectures, both skb_queue_len() and SKB_TRUESIZE(0) evaluate to 32-bit values. The multiplication can overflow before being assigned to the u64 skb_overhead variable, making the skb overhead check ineffective. Cast skb_queue_len() to u64 so the multiplication is always performed in 64-bit arithmetic. This issue was reported by Sashiko while reviewing another patch. Fixes: 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue") Closes: https://sashiko.dev/#/patchset/20260518090656.134588-1-sgarzare%40redhat.com Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260521124732.125771-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-22vsock: keep poll shutdown state consistentZiyu Zhang
vsock_poll() reads vsk->peer_shutdown before taking the socket lock to set EPOLLHUP and EPOLLRDHUP, then reads it again after taking the lock to report EOF readability. A shutdown packet can update peer_shutdown while poll is waiting for the lock, so one poll invocation can report EOF readability without the corresponding HUP/RDHUP bits. For connectible sockets, take one peer_shutdown snapshot after lock_sock() and use it for all peer-shutdown-derived poll bits. For datagram sockets, which do not take lock_sock() in poll(), take one lockless READ_ONCE() snapshot and pair it with WRITE_ONCE() on the writer side. This keeps the peer-shutdown-derived bits internally consistent for each poll pass. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Ziyu Zhang <ziyuzhang201@gmail.com> Link: https://patch.msgid.link/20260519165636.62542-1-ziyuzhang201@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-21vsock/virtio: fix skb overhead accounting to preserve full buf_allocStefano Garzarella
After commit 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue"), virtio_transport_inc_rx_pkt() subtracts per-skb overhead from buf_alloc when checking whether a new packet fits. This reduces the effective receive buffer below what the user configured via SO_VM_SOCKETS_BUFFER_SIZE, causing legitimate data packets to be silently dropped and applications that rely on the full buffer size to deadlock. Also, the reduced space is not communicated to the remote peer, so its credit calculation accounts more credit than the receiver will actually accept, causing data loss (there is no retransmission). With this approach we currently have failures in tools/testing/vsock/vsock_test.c. Test 18 sometimes fails, while test 22 always fails in this way: 18 - SOCK_STREAM MSG_ZEROCOPY...hash mismatch 22 - SOCK_STREAM virtio credit update + SO_RCVLOWAT...send failed: Resource temporarily unavailable Fix by allowing at most `buf_alloc * 2` as the total budget for payload plus skb overhead in virtio_transport_inc_rx_pkt(), similar to how SO_RCVBUF is doubled to reserve space for sk_buff metadata. This preserves the full buf_alloc for payload under normal operation, while still bounding the skb queue growth. With this patch, all tests in tools/testing/vsock/vsock_test.c are now passing again. Fixes: 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260518090656.134588-3-sgarzare@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-21vsock/virtio: reset connection on receiving queue overflowStefano Garzarella
When there is no more space to queue an incoming packet, the packet is silently dropped. This causes data loss without any notification to either peer, since there is no retransmission. Under normal circumstances, this should never happen. However, it could happen if the other peer doesn't respect the credit, or if the skb overhead, which we recently began to take into account with commit 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue"), is too high. Fix this by resetting the connection and setting the local socket error to ENOBUFS when virtio_transport_recv_enqueue() can no longer queue a packet, so both peers are explicitly notified of the failure rather than silently losing data. Fixes: ae6fcfbf5f03 ("vsock/virtio: discard packets if credit is not respected") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260518090656.134588-2-sgarzare@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-20vsock/vmci: fix UAF when peer resets connection during handshakeMinh Nguyen
vmci_transport_recv_connecting_server() returned err = 0 for a peer RST in its default switch arm: err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL; That made vmci_transport_recv_listen() skip vsock_remove_pending(), leaving the pending socket on the listener's pending_links with sk_state = TCP_CLOSE while destroy: still dropped the explicit reference taken before schedule_delayed_work(). One second later vsock_pending_work() observed is_pending=true and performed full cleanup: vsock_remove_pending() then the two trailing sock_put(sk) calls -- the first reached refcount 0 and __sk_freed the socket, and the second wrote into the freed object: BUG: KASAN: slab-use-after-free in refcount_warn_saturate Write of size 4 at addr ffff88800b1cac80 by task kworker Workqueue: events vsock_pending_work Treat peer RST like any other unexpected packet type (err = -EINVAL). All destroy: arms now return err < 0, so vmci_transport_recv_listen() removes pending from pending_links synchronously and vsock_pending_work() takes the is_pending=false / !rejected branch, dropping only its own work reference. This also closes the multi-packet race Sashiko reported on v2: pending is removed from the list before any subsequent packet can find it. The pre-existing sk_acceptq_removed() gap on the err < 0 path of vmci_transport_recv_listen() that Sashiko also noted is not introduced or changed by this patch. Tested on lts-6.12.79 with KASAN: 52/100 unpatched -> 0/100 patched. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Cc: stable@vger.kernel.org Signed-off-by: Minh Nguyen <minhnguyen.080505@gmail.com> Acked-by: Bryan Tan <bryan-bt.tan@broadcom.com> Link: https://patch.msgid.link/20260519102310.237181-1-minhnguyen.080505@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-15vsock/virtio: fix zerocopy completion for multi-skb sendsStefano Garzarella
When a large message is fragmented into multiple skbs, the zerocopy uarg is only allocated and attached to the last skb in the loop. Non-final skbs carry pinned user pages with no completion tracking, so the kernel has no way to notify userspace when those pages are safe to reuse. If the loop breaks early the uarg is never allocated at all, leaking pinned pages with no completion notification. Fix this by following the approach used by TCP: allocate the zerocopy uarg (if not provided by the caller) before the send loop and attach it to every skb via skb_zcopy_set(), which takes a reference per skb. Each skb's completion properly decrements the refcount, and the notification only fires after the last skb is freed. On failure, if no data was sent, the uarg is cleanly aborted via net_zcopy_put_abort(). This issue was initially discovered by sashiko while reviewing commit 1cb36e252211 ("vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting") but was pre-existing. Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support") Closes: https://sashiko.dev/#/patchset/20260420132051.217589-1-sgarzare%40redhat.com Reported-by: Maher Azzouzi <maherazz04@gmail.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Arseniy Krasnov <avkrasnov@salutedevices.com> Link: https://patch.msgid.link/20260514092948.268720-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
2026-05-04vsock/virtio: fix potential unbounded skb queueEric Dumazet
virtio_transport_inc_rx_pkt() checks vvs->rx_bytes + len > vvs->buf_alloc. virtio_transport_recv_enqueue() skips coalescing for packets with VIRTIO_VSOCK_SEQ_EOM. If fed with packets with len == 0 and VIRTIO_VSOCK_SEQ_EOM, a very large number of packets can be queued because vvs->rx_bytes stays at 0. Fix this by estimating the skb metadata size: (Number of skbs in the queue) * SKB_TRUESIZE(0) Fixes: 077706165717 ("virtio/vsock: don't use skbuff state to account credit") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Arseniy Krasnov <AVKrasnov@sberdevices.ru> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Stefano Garzarella <sgarzare@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: "Eugenio Pérez" <eperezma@redhat.com> Cc: virtualization@lists.linux.dev Link: https://patch.msgid.link/20260430122653.554058-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-29hv_sock: fix ARM64 supportHamza Mahfooz
VMBUS ring buffers must be page aligned. Therefore, the current value of 24K presents a challenge on ARM64 kernels (with 64K pages). So, use VMBUS_RING_SIZE() to ensure they are always aligned and large enough to hold all of the relevant data. Cc: stable@vger.kernel.org Fixes: 77ffe33363c0 ("hv_sock: use HV_HYP_PAGE_SIZE for Hyper-V communication") Tested-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260428125339.13963-1-hamzamahfooz@linux.microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-23hv_sock: Return -EIO for malformed/short packetsDexuan Cui
Commit f63152958994 fixes a regression, however it fails to report an error for malformed/short packets -- normally we should never see such packets, but let's report an error for them just in case. Fixes: f63152958994 ("hv_sock: Report EOF instead of -EIO for FIN") Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui <decui@microsoft.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260423064811.1371749-1-decui@microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-23vsock/virtio: fix MSG_ZEROCOPY pinned-pages accountingStefano Garzarella
virtio_transport_init_zcopy_skb() uses iter->count as the size argument for msg_zerocopy_realloc(), which in turn passes it to mm_account_pinned_pages() for RLIMIT_MEMLOCK accounting. However, this function is called after virtio_transport_fill_skb() has already consumed the iterator via __zerocopy_sg_from_iter(), so on the last skb, iter->count will be 0, skipping the RLIMIT_MEMLOCK enforcement. Pass pkt_len (the total bytes being sent) as an explicit parameter to virtio_transport_init_zcopy_skb() instead of reading the already-consumed iter->count. This matches TCP and UDP, which both call msg_zerocopy_realloc() with the original message size. Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support") Reported-by: Yiming Qian <yimingqian591@gmail.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260420132051.217589-1-sgarzare@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-20hv_sock: Report EOF instead of -EIO for FINDexuan Cui
Commit f0c5827d07cb unluckily causes a regression for the FIN packet, and the final read syscall gets an error rather than 0. Ideally, we would want to fix hvs_channel_readable_payload() so that it could return 0 in the FIN scenario, but it's not good for the hv_sock driver to use the VMBus ringbuffer's cached priv_read_index, which is internal data in the VMBus driver. Fix the regression in hv_sock by returning 0 rather than -EIO. Fixes: f0c5827d07cb ("hv_sock: Return the readable bytes in hvs_stream_has_data()") Cc: stable@vger.kernel.org Reported-by: Ben Hillis <Ben.Hillis@microsoft.com> Reported-by: Mitchell Levy <levymitchell0@gmail.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260416191433.840637-1-decui@microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-16vsock/virtio: fix MSG_PEEK ignoring skb offset when calculating bytes to copyLuigi Leonardi
`virtio_transport_stream_do_peek()` does not account for the skb offset when computing the number of bytes to copy. This means that, after a partial recv() that advances the offset, a peek requesting more bytes than are available in the sk_buff causes `skb_copy_datagram_iter()` to go past the valid payload, resulting in a -EFAULT. The dequeue path already handles this correctly. Apply the same logic to the peek path. Fixes: 0df7cd3c13e4 ("vsock/virtio/vhost: read data from non-linear skb") Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Arseniy Krasnov <avkrasnov@salutedevices.com> Signed-off-by: Luigi Leonardi <leonardi@redhat.com> Link: https://patch.msgid.link/20260415-fix_peek-v4-1-8207e872759e@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-16vsock/virtio: fix accept queue count leak on transport mismatchDudu Lu
virtio_transport_recv_listen() calls sk_acceptq_added() before vsock_assign_transport(). If vsock_assign_transport() fails or selects a different transport, the error path returns without calling sk_acceptq_removed(), permanently incrementing sk_ack_backlog. After approximately backlog+1 such failures, sk_acceptq_is_full() returns true, causing the listener to reject all new connections. Fix by moving sk_acceptq_added() to after the transport validation, matching the pattern used by vmci_transport and hyperv_transport. Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Signed-off-by: Dudu Lu <phx0fer@gmail.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Luigi Leonardi <leonardi@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260413131409.19022-1-phx0fer@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in late fixes in preparation for the net-next PR. Conflicts: include/net/sch_generic.h a6bd339dbb351 ("net_sched: fix skb memory leak in deferred qdisc drops") ff2998f29f390 ("net: sched: introduce qdisc-specific drop reason tracing") https://lore.kernel.org/adz0iX85FHMz0HdO@sirena.org.uk drivers/net/ethernet/airoha/airoha_eth.c 1acdfbdb516b ("net: airoha: Fix VIP configuration for AN7583 SoC") bf3471e6e6c0 ("net: airoha: Make flow control source port mapping dependent on nbq parameter") Adjacent changes: drivers/net/ethernet/airoha/airoha_ppe.c f44218cd5e6a ("net: airoha: Reset PPE cpu port configuration in airoha_ppe_hw_init()") 7da62262ec96 ("inet: add ip_local_port_step_width sysctl to improve port usage distribution") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-12vsock: fix buffer size clamping orderNorbert Szetei
In vsock_update_buffer_size(), the buffer size was being clamped to the maximum first, and then to the minimum. If a user sets a minimum buffer size larger than the maximum, the minimum check overrides the maximum check, inverting the constraint. This breaks the intended socket memory boundaries by allowing the vsk->buffer_size to grow beyond the configured vsk->buffer_max_size. Fix this by checking the minimum first, and then the maximum. This ensures the buffer size never exceeds the buffer_max_size. Fixes: b9f2b0ffde0c ("vsock: handle buffer_size sockopts in the core") Suggested-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Norbert Szetei <norbert@doyensec.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/180118C5-8BCF-4A63-A305-4EE53A34AB9C@doyensec.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-12vsock/virtio: remove unnecessary call to `virtio_transport_get_ops`Luigi Leonardi
`virtio_transport_send_pkt_info` gets all the transport information from the parameter `t_ops`. There is no need to call `virtio_transport_get_ops()`. Remove it. Acked-by: Arseniy Krasnov <avkrasnov@salutedevices.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Luigi Leonardi <leonardi@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260408-remove_parameter-v2-1-e00f31cf7a17@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-06vsock: avoid timeout for non-blocking accept() with empty backlogLaurence Rowe
A common pattern in epoll network servers is to eagerly accept all pending connections from the non-blocking listening socket after epoll_wait indicates the socket is ready by calling accept in a loop until EAGAIN is returned indicating that the backlog is empty. Scheduling a timeout for a non-blocking accept with an empty backlog meant AF_VSOCK sockets used by epoll network servers incurred hundreds of microseconds of additional latency per accept loop compared to AF_INET or AF_UNIX sockets. Signed-off-by: Laurence Rowe <laurencerowe@gmail.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260402204918.130395-1-laurencerowe@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.0-rc7). Conflicts: net/vmw_vsock/af_vsock.c b18c83388874 ("vsock: initialize child_ns_mode_locked in vsock_net_init()") 0de607dc4fd8 ("vsock: add G2H fallback for CIDs not owned by H2G transport") Adjacent changes: drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c ceee35e5674a ("bnxt_en: Refactor some basic ring setup and adjustment logic") 57cdfe0dc70b ("bnxt_en: Resize RSS contexts on channel count change") drivers/net/wireless/intel/iwlwifi/mld/mac80211.c 4d56037a02bd ("wifi: iwlwifi: mld: block EMLSR during TDLS connections") 687a95d204e7 ("wifi: iwlwifi: mld: correctly set wifi generation data") drivers/net/wireless/intel/iwlwifi/mld/scan.h b6045c899e37 ("wifi: iwlwifi: mld: Refactor scan command handling") ec66ec6a5a8f ("wifi: iwlwifi: mld: Fix MLO scan timing") drivers/net/wireless/intel/iwlwifi/mvm/fw.c 078df640ef05 ("wifi: iwlwifi: mld: add support for iwl_mcc_allowed_ap_type_cmd v 2") 323156c3541e ("wifi: iwlwifi: mvm: don't send a 6E related command when not supported") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-02vsock: initialize child_ns_mode_locked in vsock_net_init()Stefano Garzarella
The `child_ns_mode_locked` field lives in `struct net`, which persists across vsock module reloads. When the module is unloaded and reloaded, `vsock_net_init()` resets `mode` and `child_ns_mode` back to their default values, but does not reset `child_ns_mode_locked`. The stale lock from the previous module load causes subsequent writes to `child_ns_mode` to silently fail: `vsock_net_set_child_mode()` sees the old lock, skips updating the actual value, and returns success when the requested mode matches the stale lock. The sysctl handler reports no error, but `child_ns_mode` remains unchanged. Steps to reproduce: $ modprobe vsock $ echo local > /proc/sys/net/vsock/child_ns_mode $ cat /proc/sys/net/vsock/child_ns_mode local $ modprobe -r vsock $ modprobe vsock $ echo local > /proc/sys/net/vsock/child_ns_mode $ cat /proc/sys/net/vsock/child_ns_mode global <--- expected "local" Fix this by initializing `child_ns_mode_locked` to 0 (unlocked) in `vsock_net_init()`, so the write-once mechanism works correctly after module reload. Fixes: 102eab95f025 ("vsock: lock down child_ns_mode as write-once") Reported-by: Jin Liu <jinl@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260401092153.28462-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-24hv_sock: update outdated comment for renamed vsock_stream_recvmsg()Kexin Sun
The function vsock_stream_recvmsg() was renamed to vsock_connectible_recvmsg() by commit a9e29e5511b9 ("af_vsock: update functions for connectible socket"). Update the comment accordingly. Assisted-by: unnamed:deepseek-v3.2 coccinelle Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260321105753.6751-1-kexinsun@smail.nju.edu.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-12vsock: add G2H fallback for CIDs not owned by H2G transportAlexander Graf
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>
2026-03-02net: remove addr_len argument of recvmsg() handlersEric Dumazet
Use msg->msg_namelen as a place holder instead of a temporary variable, notably in inet[6]_recvmsg(). This removes stack canaries and allows tail-calls. $ scripts/bloat-o-meter -t vmlinux.old vmlinux add/remove: 0/0 grow/shrink: 2/19 up/down: 26/-532 (-506) Function old new delta rawv6_recvmsg 744 767 +23 vsock_dgram_recvmsg 55 58 +3 vsock_connectible_recvmsg 50 47 -3 unix_stream_recvmsg 161 158 -3 unix_seqpacket_recvmsg 62 59 -3 unix_dgram_recvmsg 42 39 -3 tcp_recvmsg 546 543 -3 mptcp_recvmsg 1568 1565 -3 ping_recvmsg 806 800 -6 tcp_bpf_recvmsg_parser 983 974 -9 ip_recv_error 588 576 -12 ipv6_recv_rxpmtu 442 428 -14 udp_recvmsg 1243 1224 -19 ipv6_recv_error 1046 1024 -22 udpv6_recvmsg 1487 1461 -26 raw_recvmsg 465 437 -28 udp_bpf_recvmsg 1027 984 -43 sock_common_recvmsg 103 27 -76 inet_recvmsg 257 175 -82 inet6_recvmsg 257 175 -82 tcp_bpf_recvmsg 663 568 -95 Total: Before=25143834, After=25143328, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260227151120.1346573-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-26Merge tag 'net-7.0-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from IPsec, Bluetooth and netfilter Current release - regressions: - wifi: fix dev_alloc_name() return value check - rds: fix recursive lock in rds_tcp_conn_slots_available Current release - new code bugs: - vsock: lock down child_ns_mode as write-once Previous releases - regressions: - core: - do not pass flow_id to set_rps_cpu() - consume xmit errors of GSO frames - netconsole: avoid OOB reads, msg is not nul-terminated - netfilter: h323: fix OOB read in decode_choice() - tcp: re-enable acceptance of FIN packets when RWIN is 0 - udplite: fix null-ptr-deref in __udp_enqueue_schedule_skb(). - wifi: brcmfmac: fix potential kernel oops when probe fails - phy: register phy led_triggers during probe to avoid AB-BA deadlock - eth: - bnxt_en: fix deleting of Ntuple filters - wan: farsync: fix use-after-free bugs caused by unfinished tasklets - xscale: check for PTP support properly Previous releases - always broken: - tcp: fix potential race in tcp_v6_syn_recv_sock() - kcm: fix zero-frag skb in frag_list on partial sendmsg error - xfrm: - fix race condition in espintcp_close() - always flush state and policy upon NETDEV_UNREGISTER event - bluetooth: - purge error queues in socket destructors - fix response to L2CAP_ECRED_CONN_REQ - eth: - mlx5: - fix circular locking dependency in dump - fix "scheduling while atomic" in IPsec MAC address query - gve: fix incorrect buffer cleanup for QPL - team: avoid NETDEV_CHANGEMTU event when unregistering slave - usb: validate USB endpoints" * tag 'net-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits) netfilter: nf_conntrack_h323: fix OOB read in decode_choice() dpaa2-switch: validate num_ifs to prevent out-of-bounds write net: consume xmit errors of GSO frames vsock: document write-once behavior of the child_ns_mode sysctl vsock: lock down child_ns_mode as write-once selftests/vsock: change tests to respect write-once child ns mode net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query net/mlx5: Fix missing devlink lock in SRIOV enable error path net/mlx5: E-switch, Clear legacy flag when moving to switchdev net/mlx5: LAG, disable MPESW in lag_disable_change() net/mlx5: DR, Fix circular locking dependency in dump selftests: team: Add a reference count leak test team: avoid NETDEV_CHANGEMTU event when unregistering slave net: mana: Fix double destroy_workqueue on service rescan PCI path MAINTAINERS: Update maintainer entry for QUALCOMM ETHQOS ETHERNET DRIVER dpll: zl3073x: Remove redundant cleanup in devm_dpll_init() selftests/net: packetdrill: Verify acceptance of FIN packets when RWIN is 0 tcp: re-enable acceptance of FIN packets when RWIN is 0 vsock: Use container_of() to get net namespace in sysctl handlers net: usb: kaweth: validate USB endpoints ...
2026-02-26vsock: lock down child_ns_mode as write-onceBobby Eshleman
Two administrator processes may race when setting child_ns_mode as one process sets child_ns_mode to "local" and then creates a namespace, but another process changes child_ns_mode to "global" between the write and the namespace creation. The first process ends up with a namespace in "global" mode instead of "local". While this can be detected after the fact by reading ns_mode and retrying, it is fragile and error-prone. Make child_ns_mode write-once so that a namespace manager can set it once and be sure it won't change. Writing a different value after the first write returns -EBUSY. This applies to all namespaces, including init_net, where an init process can write "local" to lock all future namespaces into local mode. Fixes: eafb64f40ca4 ("vsock: add netns to vsock core") Suggested-by: Daan De Meyer <daan.j.demeyer@gmail.com> Suggested-by: Stefano Garzarella <sgarzare@redhat.com> Co-developed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260223-vsock-ns-write-once-v3-2-c0cde6959923@meta.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-25vsock: Use container_of() to get net namespace in sysctl handlersGreg Kroah-Hartman
current->nsproxy is should not be accessed directly as syzbot has found that it could be NULL at times, causing crashes. Fix up the af_vsock sysctl handlers to use container_of() to deal with the current net namespace instead of attempting to rely on current. This is the same type of change done in commit 7f5611cbc487 ("rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Fixes: eafb64f40ca4 ("vsock: add netns to vsock core") Link: https://patch.msgid.link/2026022318-rearview-gallery-ae13@gregkh Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-19Merge tag 'net-7.0-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from Netfilter. Current release - new code bugs: - net: fix backlog_unlock_irq_restore() vs CONFIG_PREEMPT_RT - eth: mlx5e: XSK, Fix unintended ICOSQ change - phy_port: correctly recompute the port's linkmodes - vsock: prevent child netns mode switch from local to global - couple of kconfig fixes for new symbols Previous releases - regressions: - nfc: nci: fix false-positive parameter validation for packet data - net: do not delay zero-copy skbs in skb_attempt_defer_free() Previous releases - always broken: - mctp: ensure our nlmsg responses to user space are zero-initialised - ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() - fixes for ICMP rate limiting Misc: - intel: fix PCI device ID conflict between i40e and ipw2200" * tag 'net-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (85 commits) net: nfc: nci: Fix parameter validation for packet data net/mlx5e: Use unsigned for mlx5e_get_max_num_channels net/mlx5e: Fix deadlocks between devlink and netdev instance locks net/mlx5e: MACsec, add ASO poll loop in macsec_aso_set_arm_event net/mlx5: Fix misidentification of write combining CQE during poll loop net/mlx5e: Fix misidentification of ASO CQE during poll loop net/mlx5: Fix multiport device check over light SFs bonding: alb: fix UAF in rlb_arp_recv during bond up/down bnge: fix reserving resources from FW eth: fbnic: Advertise supported XDP features. rds: tcp: fix uninit-value in __inet_bind net/rds: Fix NULL pointer dereference in rds_tcp_accept_one octeontx2-af: Fix default entries mcam entry action net/mlx5e: XSK, Fix unintended ICOSQ change ipv6: icmp: icmpv6_xrlim_allow() optimization if net.ipv6.icmp.ratelimit is zero ipv4: icmp: icmpv4_xrlim_allow() optimization if net.ipv4.icmp_ratelimit is zero ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow() inet: move icmp_global_{credit,stamp} to a separate cache line icmp: prevent possible overflow in icmp_global_allow() selftests/net: packetdrill: add ipv4-mapped-ipv6 tests ...
2026-02-13vsock: prevent child netns mode switch from local to globalStefano Garzarella
A "local" namespace can change its `child_ns_mode` sysctl to "global", allowing nested namespaces to access global CIDs. This can be exploited by an unprivileged user who gained CAP_NET_ADMIN through a user namespace. Prevent this by rejecting writes that attempt to set `child_ns_mode` to "global" when the current namespace's mode is "local". Fixes: eafb64f40ca4 ("vsock: add netns to vsock core") Cc: bobbyeshleman@meta.com Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260212205916.97533-3-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-13vsock: fix child netns mode initializationStefano Garzarella
When a new network namespace is created, vsock_net_init() correctly initializes the namespace's mode by reading the parent's `child_ns_mode` via vsock_net_child_mode(). However, the `child_ns_mode` of the new namespace was always hardcoded to VSOCK_NET_MODE_GLOBAL, regardless of its own mode. This means that if a parent namespace has `child_ns_mode` set to "local", the child namespace correctly gets mode "local", but its `child_ns_mode` is reset to "global". As a result, further nested namespaces will incorrectly get mode "global" instead of inheriting "local", breaking the expected propagation of the mode through nested namespaces. Fix this by initializing `child_ns_mode` to the namespace's own mode, so the setting propagates correctly through all levels of nesting. Fixes: eafb64f40ca4 ("vsock: add netns to vsock core") Cc: bobbyeshleman@meta.com Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260212205916.97533-2-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-13Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: - in-order support in virtio core - multiple address space support in vduse - fixes, cleanups all over the place, notably dma alignment fixes for non-cache-coherent systems * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (59 commits) vduse: avoid adding implicit padding vhost: fix caching attributes of MMIO regions by setting them explicitly vdpa/mlx5: update MAC address handling in mlx5_vdpa_set_attr() vdpa/mlx5: reuse common function for MAC address updates vdpa/mlx5: update mlx_features with driver state check crypto: virtio: Replace package id with numa node id crypto: virtio: Remove duplicated virtqueue_kick in virtio_crypto_skcipher_crypt_req crypto: virtio: Add spinlock protection with virtqueue notification Documentation: Add documentation for VDUSE Address Space IDs vduse: bump version number vduse: add vq group asid support vduse: merge tree search logic of IOTLB_GET_FD and IOTLB_GET_INFO ioctls vduse: take out allocations from vduse_dev_alloc_coherent vduse: remove unused vaddr parameter of vduse_domain_free_coherent vduse: refactor vdpa_dev_add for goto err handling vhost: forbid change vq groups ASID if DRIVER_OK is set vdpa: document set_group_asid thread safety vduse: return internal vq group struct as map token vduse: add vq group support vduse: add v1 API definition ...
2026-02-04vmw_vsock: bypass false-positive Wnonnull warning with gcc-16Arnd Bergmann
The gcc-16.0.1 snapshot produces a false-positive warning that turns into a build failure with CONFIG_WERROR: In file included from arch/x86/include/asm/string.h:6, from net/vmw_vsock/vmci_transport.c:10: In function 'vmci_transport_packet_init', inlined from '__vmci_transport_send_control_pkt.constprop' at net/vmw_vsock/vmci_transport.c:198:2: arch/x86/include/asm/string_32.h:150:25: error: argument 2 null where non-null expected because argument 3 is nonzero [-Werror=nonnull] 150 | #define memcpy(t, f, n) __builtin_memcpy(t, f, n) | ^~~~~~~~~~~~~~~~~~~~~~~~~ net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); | ^~~~~~ arch/x86/include/asm/string_32.h:150:25: note: in a call to built-in function '__builtin_memcpy' net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); | ^~~~~~ This seems relatively harmless, and it so far the only instance of this warning I have found. The __vmci_transport_send_control_pkt function is called either with wait=NULL or with one of the type values that pass 'wait' into memcpy() here, but not from the same caller. Replacing the memcpy with a struct assignment is otherwise the same but avoids the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Bryan Tan <bryan-bt.tan@broadcom.com> Link: https://patch.msgid.link/20260203163406.2636463-1-arnd@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28vsock/virtio: reorder fields to reduce paddingMichael S. Tsirkin
Reorder struct virtio_vsock fields to place the DMA buffer (event_list) last. This eliminates the padding from aligning the struct size on ARCH_DMA_MINALIGN. Message-ID: <ce44f61af415521e00ab7492aa16d3d19f00bd5e.1769632071.git.mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2026-01-27vsock: add netns support to virtio transportsBobby Eshleman
Add netns support to loopback and vhost. Keep netns disabled for virtio-vsock, but add necessary changes to comply with common API updates. This is the patch in the series when vhost-vsock namespaces actually come online. Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260121-vsock-vmtest-v16-3-2859a7512097@meta.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-27virtio: set skb owner of virtio_transport_reset_no_sock() replyBobby Eshleman
Associate reply packets with the sending socket. When vsock must reply with an RST packet and there exists a sending socket (e.g., for loopback), setting the skb owner to the socket correctly handles reference counting between the skb and sk (i.e., the sk stays alive until the skb is freed). This allows the net namespace to be used for socket lookups for the duration of the reply skb's lifetime, preventing race conditions between the namespace lifecycle and vsock socket search using the namespace pointer. Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260121-vsock-vmtest-v16-2-2859a7512097@meta.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-27vsock: add netns to vsock coreBobby Eshleman
Add netns logic to vsock core. Additionally, modify transport hook prototypes to be used by later transport-specific patches (e.g., *_seqpacket_allow()). Namespaces are supported primarily by changing socket lookup functions (e.g., vsock_find_connected_socket()) to take into account the socket namespace and the namespace mode before considering a candidate socket a "match". This patch also introduces the sysctl /proc/sys/net/vsock/ns_mode to report the mode and /proc/sys/net/vsock/child_ns_mode to set the mode for new namespaces. Add netns functionality (initialization, passing to transports, procfs, etc...) to the af_vsock socket layer. Later patches that add netns support to transports depend on this patch. This patch changes the allocation of random ports for connectible vsocks in order to avoid leaking the random port range starting point to other namespaces. dgram_allow(), stream_allow(), and seqpacket_allow() callbacks are modified to take a vsk in order to perform logic on namespace modes. In future patches, the net will also be used for socket lookups in these functions. Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260121-vsock-vmtest-v16-1-2859a7512097@meta.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-22vsock/virtio: cap TX credit to local buffer sizeMelbin K Mathew
The virtio transports derives its TX credit directly from peer_buf_alloc, which is set from the remote endpoint's SO_VM_SOCKETS_BUFFER_SIZE value. On the host side this means that the amount of data we are willing to queue for a connection is scaled by a guest-chosen buffer size, rather than the host's own vsock configuration. A malicious guest can advertise a large buffer and read slowly, causing the host to allocate a correspondingly large amount of sk_buff memory. The same thing would happen in the guest with a malicious host, since virtio transports share the same code base. Introduce a small helper, virtio_transport_tx_buf_size(), that returns min(peer_buf_alloc, buf_alloc), and use it wherever we consume peer_buf_alloc. This ensures the effective TX window is bounded by both the peer's advertised buffer and our own buf_alloc (already clamped to buffer_max_size via SO_VM_SOCKETS_BUFFER_MAX_SIZE), so a remote peer cannot force the other to queue more data than allowed by its own vsock settings. On an unpatched Ubuntu 22.04 host (~64 GiB RAM), running a PoC with 32 guest vsock connections advertising 2 GiB each and reading slowly drove Slab/SUnreclaim from ~0.5 GiB to ~57 GiB; the system only recovered after killing the QEMU process. That said, if QEMU memory is limited with cgroups, the maximum memory used will be limited. With this patch applied: Before: MemFree: ~61.6 GiB Slab: ~142 MiB SUnreclaim: ~117 MiB After 32 high-credit connections: MemFree: ~61.5 GiB Slab: ~178 MiB SUnreclaim: ~152 MiB Only ~35 MiB increase in Slab/SUnreclaim, no host OOM, and the guest remains responsive. Compatibility with non-virtio transports: - VMCI uses the AF_VSOCK buffer knobs to size its queue pairs per socket based on the local vsk->buffer_* values; the remote side cannot enlarge those queues beyond what the local endpoint configured. - Hyper-V's vsock transport uses fixed-size VMBus ring buffers and an MTU bound; there is no peer-controlled credit field comparable to peer_buf_alloc, and the remote endpoint cannot drive in-flight kernel memory above those ring sizes. - The loopback path reuses virtio_transport_common.c, so it naturally follows the same semantics as the virtio transport. This change is limited to virtio_transport_common.c and thus affects virtio-vsock, vhost-vsock, and loopback, bringing them in line with the "remote window intersected with local policy" behaviour that VMCI and Hyper-V already effectively have. Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko") Suggested-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com> [Stefano: small adjustments after changing the previous patch] [Stefano: tweak the commit message] Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Luigi Leonardi <leonardi@redhat.com> Link: https://patch.msgid.link/20260121093628.9941-4-sgarzare@redhat.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-22vsock/virtio: fix potential underflow in virtio_transport_get_credit()Melbin K Mathew
The credit calculation in virtio_transport_get_credit() uses unsigned arithmetic: ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); If the peer shrinks its advertised buffer (peer_buf_alloc) while bytes are in flight, the subtraction can underflow and produce a large positive value, potentially allowing more data to be queued than the peer can handle. Reuse virtio_transport_has_space() which already handles this case and add a comment to make it clear why we are doing that. Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko") Suggested-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com> [Stefano: use virtio_transport_has_space() instead of duplicating the code] [Stefano: tweak the commit message] Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Luigi Leonardi <leonardi@redhat.com> Link: https://patch.msgid.link/20260121093628.9941-2-sgarzare@redhat.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-15vsock/virtio: Coalesce only linear skbMichal Luczaj
vsock/virtio common tries to coalesce buffers in rx queue: if a linear skb (with a spare tail room) is followed by a small skb (length limited by GOOD_COPY_LEN = 128), an attempt is made to join them. Since the introduction of MSG_ZEROCOPY support, assumption that a small skb will always be linear is incorrect. In the zerocopy case, data is lost and the linear skb is appended with uninitialized kernel memory. Of all 3 supported virtio-based transports, only loopback-transport is affected. G2H virtio-transport rx queue operates on explicitly linear skbs; see virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G vhost-transport may allocate non-linear skbs, but only for sizes that are not considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in virtio_vsock_alloc_skb(). Ensure only linear skbs are coalesced. Note that skb_tailroom(last_skb) > 0 guarantees last_skb is linear. Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support") Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260113-vsock-recv-coalescence-v2-1-552b17837cf4@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-08vsock/virtio: use virtqueue_add_inbuf_cache_clean for eventsMichael S. Tsirkin
The event_list array contains 8 small (4-byte) events that share cachelines with each other. When CONFIG_DMA_API_DEBUG is enabled, this can trigger warnings about overlapping DMA mappings within the same cacheline. The previous patch isolated event_list in its own cache lines so the warnings are spurious. Use virtqueue_add_inbuf_cache_clean() to indicate that the CPU does not write into these fields, suppressing the warnings. Reported-by: Cong Wang <xiyou.wangcong@gmail.com> Message-ID: <4b5bf63a7ebb782d87f643466b3669df567c9fe1.1767601130.git.mst@redhat.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2026-01-08vsock/virtio: fix DMA alignment for event_listMichael S. Tsirkin
On non-cache-coherent platforms, when a structure contains a buffer used for DMA alongside fields that the CPU writes to, cacheline sharing can cause data corruption. The event_list array is used for DMA_FROM_DEVICE operations via virtqueue_add_inbuf(). The adjacent event_run and guest_cid fields are written by the CPU while the buffer is available, so mapped for the device. If these share cachelines with event_list, CPU writes can corrupt DMA data. Add __dma_from_device_group_begin()/end() annotations to ensure event_list is isolated in its own cachelines. Message-ID: <f19ebd74f70c91cab4b0178df78cf6a6e107a96b.1767601130.git.mst@redhat.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2026-01-05vsock: Make accept()ed sockets use custom setsockopt()Michal Luczaj
SO_ZEROCOPY handling in vsock_connectible_setsockopt() does not get called on accept()ed sockets due to a missing flag. Flip it. Fixes: e0718bd82e27 ("vsock: enable setting SO_ZEROCOPY") Signed-off-by: Michal Luczaj <mhal@rbox.co> Link: https://patch.msgid.link/20251229-vsock-child-sock-custom-sockopt-v2-1-64778d6c4f88@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.18-rc7). No conflicts, adjacent changes: tools/testing/selftests/net/af_unix/Makefile e1bb28bf13f4 ("selftest: af_unix: Add test for SO_PEEK_OFF.") 45a1cd8346ca ("selftests: af_unix: Add tests for ECONNRESET and EOF semantics") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20vsock: Ignore signal/timeout on connect() if already establishedMichal Luczaj
During connect(), acting on a signal/timeout by disconnecting an already established socket leads to several issues: 1. connect() invoking vsock_transport_cancel_pkt() -> virtio_transport_purge_skbs() may race with sendmsg() invoking virtio_transport_get_credit(). This results in a permanently elevated `vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling. 2. connect() resetting a connected socket's state may race with socket being placed in a sockmap. A disconnected socket remaining in a sockmap breaks sockmap's assumptions. And gives rise to WARNs. 3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a transport change/drop after TCP_ESTABLISHED. Which poses a problem for any simultaneous sendmsg() or connect() and may result in a use-after-free/null-ptr-deref. Do not disconnect socket on signal/timeout. Keep the logic for unconnected sockets: they don't linger, can't be placed in a sockmap, are rejected by sendmsg(). [1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/ [2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/ [3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/ Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20251119-vsock-interrupted-connect-v2-1-70734cf1233f@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto_ops connect() callbacks to use sockaddr_unsizedKees Cook
Update all struct proto_ops connect() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto_ops bind() callbacks to use sockaddr_unsizedKees Cook
Update all struct proto_ops bind() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>