Commit Graph

435 Commits

Author SHA1 Message Date
Linus Torvalds
8bf22c33e7 Merge tag 'net-7.0-rc1' of 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
  ...
2026-02-19 10:39:08 -08:00
Stefano Garzarella
6a997f38bd vsock: prevent child netns mode switch from local to global
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: eafb64f40c ("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>
2026-02-13 12:28:38 -08:00
Stefano Garzarella
9dd391493a vsock: fix child netns mode initialization
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: eafb64f40c ("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>
2026-02-13 12:28:38 -08:00
Linus Torvalds
a353e7260b Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
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
  ...
2026-02-13 12:02:18 -08:00
Arnd Bergmann
e25dbf561e vmw_vsock: bypass false-positive Wnonnull warning with gcc-16
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>
2026-02-04 18:40:31 -08:00
Michael S. Tsirkin
f9108dee78 vsock/virtio: reorder fields to reduce padding
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>
2026-01-28 15:32:08 -05:00
Bobby Eshleman
a69686327e vsock: add netns support to virtio transports
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>
2026-01-27 10:45:38 +01:00
Bobby Eshleman
a6ae12a599 virtio: set skb owner of virtio_transport_reset_no_sock() reply
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>
2026-01-27 10:45:38 +01:00
Bobby Eshleman
eafb64f40c vsock: add netns to vsock core
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>
2026-01-27 10:45:38 +01:00
Melbin K Mathew
8ee784fdf0 vsock/virtio: cap TX credit to local buffer size
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: 06a8fc7836 ("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>
2026-01-22 15:41:33 +01:00
Melbin K Mathew
3ef3d52a1a vsock/virtio: fix potential underflow in virtio_transport_get_credit()
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: 06a8fc7836 ("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>
2026-01-22 15:41:33 +01:00
Michal Luczaj
0386bd321d vsock/virtio: Coalesce only linear skb
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: 581512a6dc ("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>
2026-01-15 19:44:44 -08:00
Michael S. Tsirkin
db191ba0c8 vsock/virtio: use virtqueue_add_inbuf_cache_clean for events
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>
2026-01-08 09:54:26 -05:00
Michael S. Tsirkin
63dfad0517 vsock/virtio: fix DMA alignment for event_list
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>
2026-01-08 09:54:19 -05:00
Michal Luczaj
ce5e612dd4 vsock: Make accept()ed sockets use custom setsockopt()
SO_ZEROCOPY handling in vsock_connectible_setsockopt() does not get called
on accept()ed sockets due to a missing flag. Flip it.

Fixes: e0718bd82e ("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>
2026-01-05 16:14:50 -08:00
Jakub Kicinski
9e203721ec Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.18-rc7).

No conflicts, adjacent changes:

tools/testing/selftests/net/af_unix/Makefile
  e1bb28bf13 ("selftest: af_unix: Add test for SO_PEEK_OFF.")
  45a1cd8346 ("selftests: af_unix: Add tests for ECONNRESET and EOF semantics")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 09:13:26 -08:00
Michal Luczaj
002541ef65 vsock: Ignore signal/timeout on connect() if already established
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: d021c34405 ("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>
2025-11-20 07:40:06 -08:00
Kees Cook
85cb0757d7 net: Convert proto_ops connect() callbacks to use sockaddr_unsized
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>
2025-11-04 19:10:32 -08:00
Kees Cook
0e50474fa5 net: Convert proto_ops bind() callbacks to use sockaddr_unsized
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>
2025-11-04 19:10:32 -08:00
Stefano Garzarella
f7c877e753 vsock: fix lock inversion in vsock_assign_transport()
Syzbot reported a potential lock inversion deadlock between
vsock_register_mutex and sk_lock-AF_VSOCK when vsock_linger() is called.

The issue was introduced by commit 687aa0c558 ("vsock: Fix
transport_* TOCTOU") which added vsock_register_mutex locking in
vsock_assign_transport() around the transport->release() call, that can
call vsock_linger(). vsock_assign_transport() can be called with sk_lock
held. vsock_linger() calls sk_wait_event() that temporarily releases and
re-acquires sk_lock. During this window, if another thread hold
vsock_register_mutex while trying to acquire sk_lock, a circular
dependency is created.

Fix this by releasing vsock_register_mutex before calling
transport->release() and vsock_deassign_transport(). This is safe
because we don't need to hold vsock_register_mutex while releasing the
old transport, and we ensure the new transport won't disappear by
obtaining a module reference first via try_module_get().

Reported-by: syzbot+10e35716f8e4929681fa@syzkaller.appspotmail.com
Tested-by: syzbot+10e35716f8e4929681fa@syzkaller.appspotmail.com
Fixes: 687aa0c558 ("vsock: Fix transport_* TOCTOU")
Cc: mhal@rbox.co
Cc: stable@vger.kernel.org
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20251021121718.137668-1-sgarzare@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-23 16:07:58 +02:00
Linus Torvalds
2215336295 Merge tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:

 - Unify guest entry code for KVM and MSHV (Sean Christopherson)

 - Switch Hyper-V MSI domain to use msi_create_parent_irq_domain()
   (Nam Cao)

 - Add CONFIG_HYPERV_VMBUS and limit the semantics of CONFIG_HYPERV
   (Mukesh Rathor)

 - Add kexec/kdump support on Azure CVMs (Vitaly Kuznetsov)

 - Deprecate hyperv_fb in favor of Hyper-V DRM driver (Prasanna
   Kumar T S M)

 - Miscellaneous enhancements, fixes and cleanups (Abhishek Tiwari,
   Alok Tiwari, Nuno Das Neves, Wei Liu, Roman Kisel, Michael Kelley)

* tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hyperv: Remove the spurious null directive line
  MAINTAINERS: Mark hyperv_fb driver Obsolete
  fbdev/hyperv_fb: deprecate this in favor of Hyper-V DRM driver
  Drivers: hv: Make CONFIG_HYPERV bool
  Drivers: hv: Add CONFIG_HYPERV_VMBUS option
  Drivers: hv: vmbus: Fix typos in vmbus_drv.c
  Drivers: hv: vmbus: Fix sysfs output format for ring buffer index
  Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()
  x86/hyperv: Switch to msi_create_parent_irq_domain()
  mshv: Use common "entry virt" APIs to do work in root before running guest
  entry: Rename "kvm" entry code assets to "virt" to genericize APIs
  entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper
  mshv: Handle NEED_RESCHED_LAZY before transferring to guest
  x86/hyperv: Add kexec/kdump support on Azure CVMs
  Drivers: hv: Simplify data structures for VMBus channel close message
  Drivers: hv: util: Cosmetic changes for hv_utils_transport.c
  mshv: Add support for a new parent partition configuration
  clocksource: hyper-v: Skip unnecessary checks for the root partition
  hyperv: Add missing field to hv_output_map_device_interrupt
2025-10-07 08:40:15 -07:00
Mukesh Rathor
94b04355e6 Drivers: hv: Add CONFIG_HYPERV_VMBUS option
At present VMBus driver is hinged off of CONFIG_HYPERV which entails
lot of builtin code and encompasses too much. It's not always clear
what depends on builtin hv code and what depends on VMBus. Setting
CONFIG_HYPERV as a module and fudging the Makefile to switch to builtin
adds even more confusion. VMBus is an independent module and should have
its own config option. Also, there are scenarios like baremetal dom0/root
where support is built in with CONFIG_HYPERV but without VMBus. Lastly,
there are more features coming down that use CONFIG_HYPERV and add more
dependencies on it.

So, create a fine grained HYPERV_VMBUS option and update Kconfigs for
dependency on VMBus.

Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# drivers/pci
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-10-01 00:00:42 +00:00
Marco Crivellari
27ce71e1ce net: WQ_PERCPU added to alloc_workqueue users
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.

alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This change adds a new WQ_PERCPU flag at the network subsystem, to explicitly
request the use of the per-CPU behavior. Both flags coexist for one release
cycle to allow callers to transition their calls.

Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.

All existing users have been updated accordingly.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20250918142427.309519-4-marco.crivellari@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 17:40:30 -07:00
Marco Crivellari
5fd8bb982e net: replace use of system_wq with system_percpu_wq
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.

This lack of consistentcy cannot be addressed without refactoring the API.

system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.

Adding system_dfl_wq to encourage its use when unbound work should be used.

The old system_unbound_wq will be kept for a few release cycles.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20250918142427.309519-3-marco.crivellari@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 17:40:30 -07:00
Jakub Kicinski
d23ad54de7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.17-rc4).

No conflicts.

Adjacent changes:

drivers/net/ethernet/intel/idpf/idpf_txrx.c
  02614eee26 ("idpf: do not linearize big TSO packets")
  6c4e684802 ("idpf: remove obsolete stashing code")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29 11:48:01 -07:00
Will Deacon
7fb1291257 vsock/virtio: Fix message iterator handling on transmit path
Commit 6693731487 ("vsock/virtio: Allocate nonlinear SKBs for handling
large transmit buffers") converted the virtio vsock transmit path to
utilise nonlinear SKBs when handling large buffers. As part of this
change, virtio_transport_fill_skb() was updated to call
skb_copy_datagram_from_iter() instead of memcpy_from_msg() as the latter
expects a single destination buffer and cannot handle nonlinear SKBs
correctly.

Unfortunately, during this conversion, I overlooked the error case when
the copying function returns -EFAULT due to a fault on the input buffer
in userspace. In this case, memcpy_from_msg() reverts the iterator to
its initial state thanks to copy_from_iter_full() whereas
skb_copy_datagram_from_iter() leaves the iterator partially advanced.
This results in a WARN_ONCE() from the vsock code, which expects the
iterator to stay in sync with the number of bytes transmitted so that
virtio_transport_send_pkt_info() can return -EFAULT when it is called
again:

  ------------[ cut here ]------------
  'send_pkt()' returns 0, but 65536 expected
  WARNING: CPU: 0 PID: 5503 at net/vmw_vsock/virtio_transport_common.c:428 virtio_transport_send_pkt_info+0xd11/0xf00 net/vmw_vsock/virtio_transport_common.c:426
  Modules linked in:
  CPU: 0 UID: 0 PID: 5503 Comm: syz.0.17 Not tainted 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full)
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014

Call virtio_transport_fill_skb_full() to restore the previous iterator
behaviour.

Cc: Jason Wang <jasowang@redhat.com>
Cc: Stefano Garzarella <sgarzare@redhat.com>
Fixes: 6693731487 ("vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers")
Reported-by: syzbot+b4d960daf7a3c7c2b7b1@syzkaller.appspotmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20250818180355.29275-3-will@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-21 17:49:19 -07:00
Jakub Kicinski
f24775c325 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.17-rc2).

No conflicts.

Adjacent changes:

drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
  d7a276a576 ("net: stmmac: rk: convert to suspend()/resume() methods")
  de1e963ad0 ("net: stmmac: rk: put the PHY clock on remove")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-14 12:13:00 -07:00
Wang Liang
4d18083d6b vsock: use sizeof(struct sockaddr_storage) instead of magic value
Previous commit 230b183921 ("net: Use standard structures for generic
socket address structures.") use 'struct sockaddr_storage address;'
to replace 'char address[MAX_SOCK_ADDR];'.

The macro MAX_SOCK_ADDR is removed by commit 01893c82b4 ("net: Remove
MAX_SOCK_ADDR constant").

The comment in vsock_getname() is outdated, use sizeof(struct
sockaddr_storage) instead of magic value 128.

Signed-off-by: Wang Liang <wangliang74@huawei.com>
Link: https://patch.msgid.link/20250812015929.1419896-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-13 17:05:21 -07:00
Budimir Markovic
aba0c94f61 vsock: Do not allow binding to VMADDR_PORT_ANY
It is possible for a vsock to autobind to VMADDR_PORT_ANY. This can
cause a use-after-free when a connection is made to the bound socket.
The socket returned by accept() also has port VMADDR_PORT_ANY but is not
on the list of unbound sockets. Binding it will result in an extra
refcount decrement similar to the one fixed in fcdd2242c0 (vsock: Keep
the binding until socket destruction).

Modify the check in __vsock_bind_connectible() to also prevent binding
to VMADDR_PORT_ANY.

Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Budimir Markovic <markovicbudimir@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250807041811.678-1-markovicbudimir@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-08 12:55:00 -07:00
Linus Torvalds
821c9e515d Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:

 - vhost can now support legacy threading if enabled in Kconfig

 - vsock memory allocation strategies for large buffers have been
   improved, reducing pressure on kmalloc

 - vhost now supports the in-order feature. guest bits missed the merge
   window.

 - fixes, cleanups all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (30 commits)
  vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers
  vsock/virtio: Rename virtio_vsock_skb_rx_put()
  vhost/vsock: Allocate nonlinear SKBs for handling large receive buffers
  vsock/virtio: Move SKB allocation lower-bound check to callers
  vsock/virtio: Rename virtio_vsock_alloc_skb()
  vsock/virtio: Resize receive buffers so that each SKB fits in a 4K page
  vsock/virtio: Move length check to callers of virtio_vsock_skb_rx_put()
  vsock/virtio: Validate length in packet header before skb_put()
  vhost/vsock: Avoid allocating arbitrarily-sized SKBs
  vhost_net: basic in_order support
  vhost: basic in order support
  vhost: fail early when __vhost_add_used() fails
  vhost: Reintroduce kthread API and add mode selection
  vdpa: Fix IDR memory leak in VDUSE module exit
  vdpa/mlx5: Fix release of uninitialized resources on error path
  vhost-scsi: Fix check for inline_sg_cnt exceeding preallocated limit
  virtio: virtio_dma_buf: fix missing parameter documentation
  vhost: Fix typos
  vhost: vringh: Remove unused functions
  vhost: vringh: Remove unused iotlb functions
  ...
2025-08-01 14:17:48 -07:00
Will Deacon
6693731487 vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers
When transmitting a vsock packet, virtio_transport_send_pkt_info() calls
virtio_transport_alloc_linear_skb() to allocate and fill SKBs with the
transmit data. Unfortunately, these are always linear allocations and
can therefore result in significant pressure on kmalloc() considering
that the maximum packet size (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE +
VIRTIO_VSOCK_SKB_HEADROOM) is a little over 64KiB, resulting in a 128KiB
allocation for each packet.

Rework the vsock SKB allocation so that, for sizes with page order
greater than PAGE_ALLOC_COSTLY_ORDER, a nonlinear SKB is allocated
instead with the packet header in the SKB and the transmit data in the
fragments. Note that this affects both the vhost and virtio transports.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-10-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-08-01 09:11:09 -04:00
Will Deacon
8ca76151d2 vsock/virtio: Rename virtio_vsock_skb_rx_put()
In preparation for using virtio_vsock_skb_rx_put() when populating SKBs
on the vsock TX path, rename virtio_vsock_skb_rx_put() to
virtio_vsock_skb_put().

No functional change.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-9-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-08-01 09:11:09 -04:00
Will Deacon
2304c64a28 vsock/virtio: Rename virtio_vsock_alloc_skb()
In preparation for nonlinear allocations for large SKBs, rename
virtio_vsock_alloc_skb() to virtio_vsock_alloc_linear_skb() to indicate
that it returns linear SKBs unconditionally and switch all callers over
to this new interface for now.

No functional change.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-6-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-08-01 09:11:09 -04:00
Will Deacon
03a92f036a vsock/virtio: Resize receive buffers so that each SKB fits in a 4K page
When allocating receive buffers for the vsock virtio RX virtqueue, an
SKB is allocated with a 4140 data payload (the 44-byte packet header +
VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE). Even when factoring in the SKB
overhead, the resulting 8KiB allocation thanks to the rounding in
kmalloc_reserve() is wasteful (~3700 unusable bytes) and results in a
higher-order page allocation on systems with 4KiB pages just for the
sake of a few hundred bytes of packet data.

Limit the vsock virtio RX buffers to 4KiB per SKB, resulting in much
better memory utilisation and removing the need to allocate higher-order
pages entirely.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-5-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-08-01 09:11:09 -04:00
Will Deacon
87dbae5e36 vsock/virtio: Move length check to callers of virtio_vsock_skb_rx_put()
virtio_vsock_skb_rx_put() only calls skb_put() if the length in the
packet header is not zero even though skb_put() handles this case
gracefully.

Remove the functionally redundant check from virtio_vsock_skb_rx_put()
and, on the assumption that this is a worthwhile optimisation for
handling credit messages, augment the existing length checks in
virtio_transport_rx_work() to elide the call for zero-length payloads.
Since the callers all have the length, extend virtio_vsock_skb_rx_put()
to take it as an additional parameter rather than fish it back out of
the packet header.

Note that the vhost code already has similar logic in
vhost_vsock_alloc_skb().

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-4-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-08-01 09:11:09 -04:00
Will Deacon
0dab924844 vsock/virtio: Validate length in packet header before skb_put()
When receiving a vsock packet in the guest, only the virtqueue buffer
size is validated prior to virtio_vsock_skb_rx_put(). Unfortunately,
virtio_vsock_skb_rx_put() uses the length from the packet header as the
length argument to skb_put(), potentially resulting in SKB overflow if
the host has gone wonky.

Validate the length as advertised by the packet header before calling
virtio_vsock_skb_rx_put().

Cc: <stable@vger.kernel.org>
Fixes: 71dc9ec9ac ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-3-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2025-08-01 09:11:09 -04:00
Wang Liang
002f79a5f0 vsock: remove unnecessary null check in vsock_getname()
The local variable 'vm_addr' is always not NULL, no need to check it.

Signed-off-by: Wang Liang <wangliang74@huawei.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250725013808.337924-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-26 11:26:20 -07:00
Jakub Kicinski
3321e97eab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.16-rc6).

No conflicts.

Adjacent changes:

Documentation/devicetree/bindings/net/allwinner,sun8i-a83t-emac.yaml
  0a12c435a1 ("dt-bindings: net: sun8i-emac: Add A100 EMAC compatible")
  b3603c0466 ("dt-bindings: net: sun8i-emac: Rename A523 EMAC0 to GMAC0")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-10 10:10:49 -07:00
Xuewei Niu
f7c7226592 vsock: Add support for SIOCINQ ioctl
Add support for SIOCINQ ioctl, indicating the length of bytes unread in the
socket. The value is obtained from `vsock_stream_has_data()`.

Signed-off-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20250708-siocinq-v6-2-3775f9a9e359@antgroup.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-09 19:29:52 -07:00
Dexuan Cui
f0c5827d07 hv_sock: Return the readable bytes in hvs_stream_has_data()
When hv_sock was originally added, __vsock_stream_recvmsg() and
vsock_stream_has_data() actually only needed to know whether there
is any readable data or not, so hvs_stream_has_data() was written to
return 1 or 0 for simplicity.

However, now hvs_stream_has_data() should return the readable bytes
because vsock_data_ready() -> vsock_stream_has_data() needs to know the
actual bytes rather than a boolean value of 1 or 0.

The SIOCINQ ioctl support also needs hvs_stream_has_data() to return
the readable bytes.

Let hvs_stream_has_data() return the readable bytes of the payload in
the next host-to-guest VMBus hv_sock packet.

Note: there may be multiple incoming hv_sock packets pending in the
VMBus channel's ringbuffer, but so far there is not a VMBus API that
allows us to know all the readable bytes in total without reading and
caching the payload of the multiple packets, so let's just return the
readable bytes of the next single packet. In the future, we'll either
add a VMBus API that allows us to know the total readable bytes without
touching the data in the ringbuffer, or the hv_sock driver needs to
understand the VMBus packet format and parse the packets directly.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://patch.msgid.link/20250708-siocinq-v6-1-3775f9a9e359@antgroup.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-09 19:29:52 -07:00
Michal Luczaj
1e7d9df379 vsock: Fix IOCTL_VM_SOCKETS_GET_LOCAL_CID to check also transport_local
Support returning VMADDR_CID_LOCAL in case no other vsock transport is
available.

Fixes: 0e12190578 ("vsock: add local transport support in the vsock core")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250703-vsock-transports-toctou-v4-3-98f0eb530747@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08 08:39:49 -07:00
Michal Luczaj
687aa0c558 vsock: Fix transport_* TOCTOU
Transport assignment may race with module unload. Protect new_transport
from becoming a stale pointer.

This also takes care of an insecure call in vsock_use_local_transport();
add a lockdep assert.

BUG: unable to handle page fault for address: fffffbfff8056000
Oops: Oops: 0000 [#1] SMP KASAN
RIP: 0010:vsock_assign_transport+0x366/0x600
Call Trace:
 vsock_connect+0x59c/0xc40
 __sys_connect+0xe8/0x100
 __x64_sys_connect+0x6e/0xc0
 do_syscall_64+0x92/0x1c0
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Fixes: c0cfa2d8a7 ("vsock: add multi-transports support")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250703-vsock-transports-toctou-v4-2-98f0eb530747@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08 08:39:49 -07:00
Michal Luczaj
209fd72083 vsock: Fix transport_{g2h,h2g} TOCTOU
vsock_find_cid() and vsock_dev_do_ioctl() may race with module unload.
transport_{g2h,h2g} may become NULL after the NULL check.

Introduce vsock_transport_local_cid() to protect from a potential
null-ptr-deref.

KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
RIP: 0010:vsock_find_cid+0x47/0x90
Call Trace:
 __vsock_bind+0x4b2/0x720
 vsock_bind+0x90/0xe0
 __sys_bind+0x14d/0x1e0
 __x64_sys_bind+0x6e/0xc0
 do_syscall_64+0x92/0x1c0
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
RIP: 0010:vsock_dev_do_ioctl.isra.0+0x58/0xf0
Call Trace:
 __x64_sys_ioctl+0x12d/0x190
 do_syscall_64+0x92/0x1c0
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Fixes: c0cfa2d8a7 ("vsock: add multi-transports support")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250703-vsock-transports-toctou-v4-1-98f0eb530747@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08 08:39:49 -07:00
HarshaVardhana S A
223e2288f4 vsock/vmci: Clear the vmci transport packet properly when initializing it
In vmci_transport_packet_init memset the vmci_transport_packet before
populating the fields to avoid any uninitialised data being left in the
structure.

Cc: Bryan Tan <bryan-bt.tan@broadcom.com>
Cc: Vishnu Dasa <vishnu.dasa@broadcom.com>
Cc: Broadcom internal kernel review list
Cc: Stefano Garzarella <sgarzare@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: virtualization@lists.linux.dev
Cc: netdev@vger.kernel.org
Cc: stable <stable@kernel.org>
Signed-off-by: HarshaVardhana S A <harshavardhana.sa@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250701122254.2397440-1-gregkh@linuxfoundation.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-07-03 12:52:52 +02:00
Paolo Abeni
f6bd8faeb1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes to prepare for the 6.16 net-next PR.

No conflicts nor adjacent changes.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-28 10:11:15 +02:00
Michal Luczaj
5ec40864aa vsock: Move lingering logic to af_vsock core
Lingering should be transport-independent in the long run. In preparation
for supporting other transports, as well as the linger on shutdown(), move
code to core.

Generalize by querying vsock_transport::unsent_bytes(), guard against the
callback being unimplemented. Do not pass sk_lingertime explicitly. Pull
SOCK_LINGER check into vsock_linger().

Flatten the function. Remove the nested block by inverting the condition:
return early on !timeout.

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250522-vsock-linger-v6-2-2ad00b0e447e@rbox.co
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-27 11:05:21 +02:00
Michal Luczaj
1c39f5dbbf vsock/virtio: Linger on unsent data
Currently vsock's lingering effectively boils down to waiting (or timing
out) until packets are consumed or dropped by the peer; be it by receiving
the data, closing or shutting down the connection.

To align with the semantics described in the SO_LINGER section of man
socket(7) and to mimic AF_INET's behaviour more closely, change the logic
of a lingering close(): instead of waiting for all data to be handled,
block until data is considered sent from the vsock's transport point of
view. That is until worker picks the packets for processing and decrements
virtio_vsock_sock::bytes_unsent down to 0.

Note that (some interpretation of) lingering was always limited to
transports that called virtio_transport_wait_close() on transport release.
This does not change, i.e. under Hyper-V and VMCI no lingering would be
observed.

The implementation does not adhere strictly to man page's interpretation of
SO_LINGER: shutdown() will not trigger the lingering. This follows AF_INET.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250522-vsock-linger-v6-1-2ad00b0e447e@rbox.co
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-27 11:05:21 +02:00
Stefano Garzarella
45ca7e9f07 vsock/virtio: fix rx_bytes accounting for stream sockets
In `struct virtio_vsock_sock`, we maintain two counters:
- `rx_bytes`: used internally to track how many bytes have been read.
  This supports mechanisms like .stream_has_data() and sock_rcvlowat().
- `fwd_cnt`: used for the credit mechanism to inform available receive
  buffer space to the remote peer.

These counters are updated via virtio_transport_inc_rx_pkt() and
virtio_transport_dec_rx_pkt().

Since the beginning with commit 06a8fc7836 ("VSOCK: Introduce
virtio_vsock_common.ko"), we call virtio_transport_dec_rx_pkt() in
virtio_transport_stream_do_dequeue() only when we consume the entire
packet, so partial reads, do not update `rx_bytes` and `fwd_cnt`.

This is fine for `fwd_cnt`, because we still have space used for the
entire packet, and we don't want to update the credit for the other
peer until we free the space of the entire packet. However, this
causes `rx_bytes` to be stale on partial reads.

Previously, this didn’t cause issues because `rx_bytes` was used only by
.stream_has_data(), and any unread portion of a packet implied data was
still available. However, since commit 93b8088766
("virtio/vsock: fix logic which reduces credit update messages"), we now
rely on `rx_bytes` to determine if a credit update should be sent when
the data in the RX queue drops below SO_RCVLOWAT value.

This patch fixes the accounting by updating `rx_bytes` with the number
of bytes actually read, even on partial reads, while leaving `fwd_cnt`
untouched until the packet is fully consumed. Also introduce a new
`buf_used` counter to check that the remote peer is honoring the given
credit; this was previously done via `rx_bytes`.

Fixes: 93b8088766 ("virtio/vsock: fix logic which reduces credit update messages")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250521121705.196379-1-sgarzare@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-26 19:04:21 +02:00
Mina Almasry
bd61848900 net: devmem: Implement TX path
Augment dmabuf binding to be able to handle TX. Additional to all the RX
binding, we also create tx_vec needed for the TX path.

Provide API for sendmsg to be able to send dmabufs bound to this device:

- Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from.
- MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf.

Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY
implementation, while disabling instances where MSG_ZEROCOPY falls back
to copying.

We additionally pipe the binding down to the new
zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems
instead of the traditional page netmems.

We also special case skb_frag_dma_map to return the dma-address of these
dmabuf net_iovs instead of attempting to map pages.

The TX path may release the dmabuf in a context where we cannot wait.
This happens when the user unbinds a TX dmabuf while there are still
references to its netmems in the TX path. In that case, the netmems will
be put_netmem'd from a context where we can't unmap the dmabuf, Resolve
this by making __net_devmem_dmabuf_binding_free schedule_work'd.

Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat
of the implementation came from devmem TCP RFC v1[1], which included the
TX path, but Stan did all the rebasing on top of netmem/net_iov.

Cc: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-13 11:12:48 +02:00
Stefano Garzarella
fccd2b711d vsock: avoid timeout during connect() if the socket is closing
When a peer attempts to establish a connection, vsock_connect() contains
a loop that waits for the state to be TCP_ESTABLISHED. However, the
other peer can be fast enough to accept the connection and close it
immediately, thus moving the state to TCP_CLOSING.

When this happens, the peer in the vsock_connect() is properly woken up,
but since the state is not TCP_ESTABLISHED, it goes back to sleep
until the timeout expires, returning -ETIMEDOUT.

If the socket state is TCP_CLOSING, waiting for the timeout is pointless.
vsock_connect() can return immediately without errors or delay since the
connection actually happened. The socket will be in a closing state,
but this is not an issue, and subsequent calls will fail as expected.

We discovered this issue while developing a test that accepts and
immediately closes connections to stress the transport switch between
two connect() calls, where the first one was interrupted by a signal
(see Closes link).

Reported-by: Luigi Leonardi <leonardi@redhat.com>
Closes: https://lore.kernel.org/virtualization/bq6hxrolno2vmtqwcvb5bljfpb7mvwb3kohrvaed6auz5vxrfv@ijmd2f3grobn/
Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Luigi Leonardi <leonardi@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20250328141528.420719-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-02 17:19:30 -07:00