linux-stable.git/net/packet, branch v7.2 Linux kernel stable tree af_packet: Don't send zero-byte data in tpacket_snd(). 2026-08-12T00:32:53+00:00 Eric Dumazet edumazet@google.com 2026-08-10T15:04:47+00:00 6bcd76c134c55c697148acb5c0194e9666abdf84 syzbot reported a WARNING in __dev_queue_xmit() triggered via tpacket_snd(): skb_assert_len WARNING: at include/linux/skbuff.h:2753 skb_assert_len WARNING: at __dev_queue_xmit+0x21bc/0x4970 net/core/dev.c:4781 Call Trace: <TASK> dev_queue_xmit include/linux/netdevice.h:3448 [inline] packet_xmit+0x243/0x310 net/packet/af_packet.c:276 tpacket_snd net/packet/af_packet.c:2907 [inline] packet_sendmsg+0x28d6/0x4eb0 net/packet/af_packet.c:3134 When sending 0-byte packets via TPACKET ring buffer on devices with no hard header (e.g. dev->hard_header_len == 0), tpacket_fill_skb() populates an skb with skb->len == 0 and returns 0. tpacket_snd() then forwards this empty skb to packet_xmit(), causing __dev_queue_xmit() to hit skb_assert_len(skb). Similar checks exist in packet_snd() via commit dc633700f00f ("net/af_packet: check len when min_header_len equals to 0") and in packet_sendmsg_spkt() via commit 6a341729fb31 ("af_packet: Don't send zero-byte data in packet_sendmsg_spkt()."). Return -EINVAL in tpacket_fill_skb() when skb->len is zero to reject zero-length packets in tpacket_snd(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+30b93b6845b19cc38581@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a79e807.01d0871a.3a0d52.00ac.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://patch.msgid.link/20260810150447.1220864-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
syzbot reported a WARNING in __dev_queue_xmit() triggered via tpacket_snd():

skb_assert_len
WARNING: at include/linux/skbuff.h:2753 skb_assert_len
WARNING: at __dev_queue_xmit+0x21bc/0x4970 net/core/dev.c:4781

Call Trace:
 <TASK>
 dev_queue_xmit include/linux/netdevice.h:3448 [inline]
 packet_xmit+0x243/0x310 net/packet/af_packet.c:276
 tpacket_snd net/packet/af_packet.c:2907 [inline]
 packet_sendmsg+0x28d6/0x4eb0 net/packet/af_packet.c:3134

When sending 0-byte packets via TPACKET ring buffer on devices with no
hard header (e.g. dev->hard_header_len == 0), tpacket_fill_skb()
populates an skb with skb->len == 0 and returns 0. tpacket_snd() then
forwards this empty skb to packet_xmit(), causing __dev_queue_xmit() to
hit skb_assert_len(skb).

Similar checks exist in packet_snd() via commit dc633700f00f
("net/af_packet: check len when min_header_len equals to 0") and in
packet_sendmsg_spkt() via commit 6a341729fb31 ("af_packet: Don't send
zero-byte data in packet_sendmsg_spkt().").

Return -EINVAL in tpacket_fill_skb() when skb->len is zero to reject
zero-length packets in tpacket_snd().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+30b93b6845b19cc38581@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a79e807.01d0871a.3a0d52.00ac.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/20260810150447.1220864-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: packet: fix wrong transport_header when sending VLAN-tagged frame 2026-08-11T11:14:00+00:00 Wei Fang wei.fang@nxp.com 2026-08-07T06:34:04+00:00 01fdecc0480d916c799dbee584833a4a37e94d06 In packet_parse_headers(), when processing a VLAN-tagged frame, skb_set_network_header() is called to advance network_header past the VLAN tag to the inner protocol header. skb_probe_transport_header() is then called with skb->protocol still set to the outer VLAN EtherType (e.g. ETH_P_8021Q), while nhoff (derived from skb_network_offset()) already points past the VLAN tag to the inner protocol header. In __skb_flow_dissect(), proto is initialized to ETH_P_8021Q and nhoff points past the VLAN tag. When the dissector hits case ETH_P_8021Q, it reads a struct vlan_hdr at nhoff via __skb_header_pointer(), but that offset contains the inner protocol header (e.g. an IP header). The bytes are misinterpreted as a VLAN header, yielding a garbage encapsulated EtherType that matches no known protocol. The dissector returns false, so skb_probe_transport_header() never calls skb_set_transport_header(), leaving transport_header at its uninitialized sentinel value (~0U). Move skb_probe_transport_header() to before skb_set_network_header(). At the time skb_probe_transport_header() is called, network_header still points to the VLAN header, so nhoff correctly points to the VLAN header. The flow dissector can then parse the VLAN header, extract the inner EtherType, and advance nhoff to the inner protocol header, allowing transport_header to be set correctly. Fixes: dfed913e8b55 ("net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO") Assisted-by: WChat:claude-opus-4-8 Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260807063405.688780-2-wei.fang@oss.nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
In packet_parse_headers(), when processing a VLAN-tagged frame,
skb_set_network_header() is called to advance network_header past the
VLAN tag to the inner protocol header. skb_probe_transport_header() is
then called with skb->protocol still set to the outer VLAN EtherType
(e.g. ETH_P_8021Q), while nhoff (derived from skb_network_offset())
already points past the VLAN tag to the inner protocol header.

In __skb_flow_dissect(), proto is initialized to ETH_P_8021Q and nhoff
points past the VLAN tag. When the dissector hits case ETH_P_8021Q, it
reads a struct vlan_hdr at nhoff via __skb_header_pointer(), but that
offset contains the inner protocol header (e.g. an IP header). The bytes
are misinterpreted as a VLAN header, yielding a garbage encapsulated
EtherType that matches no known protocol. The dissector returns false,
so skb_probe_transport_header() never calls skb_set_transport_header(),
leaving transport_header at its uninitialized sentinel value (~0U).

Move skb_probe_transport_header() to before skb_set_network_header(). At
the time skb_probe_transport_header() is called, network_header still
points to the VLAN header, so nhoff correctly points to the VLAN header.
The flow dissector can then parse the VLAN header, extract the inner
EtherType, and advance nhoff to the inner protocol header, allowing
transport_header to be set correctly.

Fixes: dfed913e8b55 ("net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO")
Assisted-by: WChat:claude-opus-4-8
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260807063405.688780-2-wei.fang@oss.nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
packet: use consistent hard_header_len in TX_RING send path 2026-08-06T16:27:21+00:00 Qihang Tang q.h.hack.winter@gmail.com 2026-08-05T12:57:29+00:00 21b5953e7494c16a42e6cd8cf110e18d13ae4a6b tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative. Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb(). The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here. Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap") Cc: stable@vger.kernel.org Signed-off-by: Qihang Tang <q.h.hack.winter@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260805125729.19220-4-q.h.hack.winter@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
tpacket_snd() reads dev->hard_header_len independently for skb
allocation and header construction in tpacket_fill_skb(). Concurrent
netdevice reconfiguration can therefore make the reserved headroom
smaller than the amount later pushed, or make copylen - hard_header_len
negative.

Snapshot hard_header_len once before processing ring frames and use it
for the frame limit, headroom allocation, copy length, and skb
construction. Pass the snapshot to tpacket_fill_skb().

The separate SOCK_DGRAM consistency problem between hard_header_len and
header_ops->create is not addressed here.

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Cc: stable@vger.kernel.org
Signed-off-by: Qihang Tang <q.h.hack.winter@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260805125729.19220-4-q.h.hack.winter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
packet: use consistent hard_header_len in non-ring send paths 2026-08-06T16:27:21+00:00 Qihang Tang q.h.hack.winter@gmail.com 2026-08-05T12:57:28+00:00 03390aa32e669cc4ecd7d34108e2e1afc13d689d packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here. Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation") Cc: stable@vger.kernel.org Signed-off-by: Qihang Tang <q.h.hack.winter@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260805125729.19220-3-q.h.hack.winter@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
packet_snd() reads dev->hard_header_len multiple times while allocating
and constructing an skb. Device reconfiguration can change this value
concurrently, for example through bonding device type changes.

For SOCK_RAW, packet_snd() can save a larger value in reserve and later
allocate headroom using a smaller value. Moving skb->data back by reserve
then places it before skb->head, and the following copy from userspace can
attempt an out-of-bounds write.

packet_sendmsg_spkt() has the same issue because it calculates its
reservation and header offset from separate reads before dropping the RCU
read lock to allocate the skb.

Add LL_RESERVED_SPACE_EX() for callers that already saved a header length.
Read hard_header_len once in packet_snd() and use it for allocation and
construction. In packet_sendmsg_spkt(), preserve the allocation-time value
through the device lookup retry.

The separate SOCK_DGRAM consistency problem between hard_header_len and
header_ops->create is not addressed here.

Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation")
Cc: stable@vger.kernel.org
Signed-off-by: Qihang Tang <q.h.hack.winter@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260805125729.19220-3-q.h.hack.winter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
packet: synchronize pressure clearing with ring reconfiguration 2026-08-04T09:38:02+00:00 Zihan Xi zihanx@nebusec.ai 2026-07-29T09:16:53+00:00 1a35da325cac4d5bcad76a2aa943408a6f1d9000 packet_set_ring() updates the RX ring state under sk_receive_queue.lock, but used to publish the tpacket receive mode through po->prot_hook.func after releasing that lock. packet_poll() and packet_recvmsg() can then run the pressure clearing path after the ring has been cleared while still seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference stale or NULL ring storage. Move the existing receive hook assignment into the same sk_receive_queue.lock section as the ring state update. Keep the assignment otherwise unchanged, including on TX ring reconfiguration, to avoid adding behavior changes that are not required for the fix. Serialize packet_recvmsg() pressure clearing with the same queue lock only after PACKET_SOCK_PRESSURE has been observed. If the flag is clear and the socket has moved away from tpacket_rcv, packet_set_ring() has already detached the socket and waited for synchronize_net(), so no new packet input can set the flag again. packet_poll() already holds sk_receive_queue.lock, so it uses the new unlocked helper directly. Fixes: 2ccdbaa6d55b ("packet: rollover lock contention avoidance") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Link: https://patch.msgid.link/f90b5688311fa278d1361ea8c6be0bf25967d591.1785247446.git.zihanx@nebusec.ai Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
packet_set_ring() updates the RX ring state under sk_receive_queue.lock,
but used to publish the tpacket receive mode through po->prot_hook.func
after releasing that lock. packet_poll() and packet_recvmsg() can then
run the pressure clearing path after the ring has been cleared while
still seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference
stale or NULL ring storage.

Move the existing receive hook assignment into the same
sk_receive_queue.lock section as the ring state update. Keep the
assignment otherwise unchanged, including on TX ring reconfiguration, to
avoid adding behavior changes that are not required for the fix.

Serialize packet_recvmsg() pressure clearing with the same queue lock
only after PACKET_SOCK_PRESSURE has been observed. If the flag is clear
and the socket has moved away from tpacket_rcv, packet_set_ring() has
already detached the socket and waited for synchronize_net(), so no new
packet input can set the flag again.

packet_poll() already holds sk_receive_queue.lock, so it uses the new
unlocked helper directly.

Fixes: 2ccdbaa6d55b ("packet: rollover lock contention avoidance")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Link: https://patch.msgid.link/f90b5688311fa278d1361ea8c6be0bf25967d591.1785247446.git.zihanx@nebusec.ai
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net/packet: reset the MAC header on the packet-socket transmit path 2026-07-30T23:29:07+00:00 Doruk Tan Ozturk doruk@0sec.ai 2026-07-24T14:40:15+00:00 c2707480cfbf19c7619acc9c089d17f20869821f packet_parse_headers() resets the MAC header only for a SOCK_RAW frame whose socket did not bind a protocol. A protocol-bound SOCK_RAW socket, any SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave skb->mac_header unset here. For frames sent via __dev_queue_xmit() this is harmless: it resets the MAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS path uses dev_direct_xmit(), which does not, so the frame reaches ndo_start_xmit() with the MAC header unset. A driver that reads eth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an out-of-bounds access ~64 KiB past the head -- the same class fixed for one consumer in commit f5089008f90c ("macsec: do not read an unset MAC header in macsec_encrypt()"). packet_parse_headers() runs only on the transmit path, where skb->data points at the start of the L2 header for every packet-socket type regardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied header and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC header unconditionally, mirroring __dev_queue_xmit(), so the frame is anchored on the bypass path too. Found by 0sec (https://0sec.ai) using automated source analysis; verified against source and matched to the macsec KASAN report in f5089008f90c. Compile-tested. Fixes: 75c65772c3d1 ("net/packet: Ask driver for protocol if not provided by user") Cc: stable@vger.kernel.org Signed-off-by: Doruk Tan Ozturk <doruk@0sec.ai> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260724144015.63219-1-doruk@0sec.ai Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
packet_parse_headers() resets the MAC header only for a SOCK_RAW frame
whose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,
any SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave
skb->mac_header unset here.

For frames sent via __dev_queue_xmit() this is harmless: it resets the
MAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS
path uses dev_direct_xmit(), which does not, so the frame reaches
ndo_start_xmit() with the MAC header unset. A driver that reads
eth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an
out-of-bounds access ~64 KiB past the head -- the same class fixed for
one consumer in commit f5089008f90c ("macsec: do not read an unset MAC
header in macsec_encrypt()").

packet_parse_headers() runs only on the transmit path, where skb->data
points at the start of the L2 header for every packet-socket type
regardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied
header and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC
header unconditionally, mirroring __dev_queue_xmit(), so the frame is
anchored on the bypass path too.

Found by 0sec (https://0sec.ai) using automated source analysis;
verified against source and matched to the macsec KASAN report in
f5089008f90c. Compile-tested.

Fixes: 75c65772c3d1 ("net/packet: Ask driver for protocol if not provided by user")
Cc: stable@vger.kernel.org
Signed-off-by: Doruk Tan Ozturk <doruk@0sec.ai>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260724144015.63219-1-doruk@0sec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/packet: avoid fanout hook re-registration after unregister 2026-07-21T01:15:20+00:00 David Lee david.lee@trailofbits.com 2026-07-07T10:44:37+00:00 50aff80475abd3533eef4320477037e6fcc6b56e packet_set_ring() temporarily detaches a socket from packet delivery while reconfiguring its ring. It records the previous running state, clears po->num, unregisters the protocol hook when needed, drops po->bind_lock, and later restores po->num and re-registers the hook from the saved was_running value. That unlocked window can race with NETDEV_UNREGISTER. The notifier can observe the socket as not running, skip __unregister_prot_hook(), and invalidate the per-socket binding by setting po->ifindex to -1 and clearing po->prot_hook.dev. A one-member fanout group can still retain its shared fanout hook device pointer. When packet_set_ring() resumes, re-registering solely from the stale was_running state can re-add the fanout hook after the device has been unregistered. Treat po->ifindex == -1 as an invalidated binding after reacquiring po->bind_lock. This is distinct from ifindex 0, the normal unbound/wildcard state: ifindex -1 marks an existing device binding that was invalidated when the device was unregistered. Restore po->num as before, but do not re-register the hook if device unregister already detached the socket. Fixes: dc99f600698d ("packet: Add fanout support.") Link: https://lore.kernel.org/netdev/20260701113947.23180-1-david.lee@trailofbits.com/ Signed-off-by: David Lee <david.lee@trailofbits.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260707104440.833129-1-david.lee@trailofbits.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
packet_set_ring() temporarily detaches a socket from packet delivery while
reconfiguring its ring. It records the previous running state, clears
po->num, unregisters the protocol hook when needed, drops po->bind_lock,
and later restores po->num and re-registers the hook from the saved
was_running value.

That unlocked window can race with NETDEV_UNREGISTER. The notifier can
observe the socket as not running, skip __unregister_prot_hook(), and
invalidate the per-socket binding by setting po->ifindex to -1 and clearing
po->prot_hook.dev. A one-member fanout group can still retain its shared
fanout hook device pointer. When packet_set_ring() resumes, re-registering
solely from the stale was_running state can re-add the fanout hook after
the device has been unregistered.

Treat po->ifindex == -1 as an invalidated binding after reacquiring
po->bind_lock. This is distinct from ifindex 0, the normal
unbound/wildcard state: ifindex -1 marks an existing device binding that
was invalidated when the device was unregistered. Restore po->num as
before, but do not re-register the hook if device unregister already
detached the socket.

Fixes: dc99f600698d ("packet: Add fanout support.")
Link: https://lore.kernel.org/netdev/20260701113947.23180-1-david.lee@trailofbits.com/
Signed-off-by: David Lee <david.lee@trailofbits.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260707104440.833129-1-david.lee@trailofbits.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/packet: fix TOCTOU race on mmap'd vnet_hdr in tpacket_snd() 2026-04-23T03:16:34+00:00 Bingquan Chen patzilla007@gmail.com 2026-04-18T11:20:06+00:00 2c054e17d9d41f1020376806c7f750834ced4dc5 In tpacket_snd(), when PACKET_VNET_HDR is enabled, vnet_hdr points directly into the mmap'd TX ring buffer shared with userspace. The kernel validates the header via __packet_snd_vnet_parse() but then re-reads all fields later in virtio_net_hdr_to_skb(). A concurrent userspace thread can modify the vnet_hdr fields between validation and use, bypassing all safety checks. The non-TPACKET path (packet_snd()) already correctly copies vnet_hdr to a stack-local variable. All other vnet_hdr consumers in the kernel (tun.c, tap.c, virtio_net.c) also use stack copies. The TPACKET TX path is the only caller of virtio_net_hdr_to_skb() that reads directly from user-controlled shared memory. Fix this by copying vnet_hdr from the mmap'd ring buffer to a stack-local variable before validation and use, consistent with the approach used in packet_snd() and all other callers. Fixes: 1d036d25e560 ("packet: tpacket_snd gso and checksum offload") Signed-off-by: Bingquan Chen <patzilla007@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260418112006.78823-1-patzilla007@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
In tpacket_snd(), when PACKET_VNET_HDR is enabled, vnet_hdr points
directly into the mmap'd TX ring buffer shared with userspace. The
kernel validates the header via __packet_snd_vnet_parse() but then
re-reads all fields later in virtio_net_hdr_to_skb(). A concurrent
userspace thread can modify the vnet_hdr fields between validation
and use, bypassing all safety checks.

The non-TPACKET path (packet_snd()) already correctly copies vnet_hdr
to a stack-local variable. All other vnet_hdr consumers in the kernel
(tun.c, tap.c, virtio_net.c) also use stack copies. The TPACKET TX
path is the only caller of virtio_net_hdr_to_skb() that reads directly
from user-controlled shared memory.

Fix this by copying vnet_hdr from the mmap'd ring buffer to a
stack-local variable before validation and use, consistent with the
approach used in packet_snd() and all other callers.

Fixes: 1d036d25e560 ("packet: tpacket_snd gso and checksum offload")
Signed-off-by: Bingquan Chen <patzilla007@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260418112006.78823-1-patzilla007@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge tag 'net-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2026-04-15T01:36:10+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-04-15T01:36:10+00:00 91a4855d6c03e770e42f17c798a36a3c46e63de2 Pull networking updates from Jakub Kicinski: "Core & protocols: - Support HW queue leasing, allowing containers to be granted access to HW queues for zero-copy operations and AF_XDP - Number of code moves to help the compiler with inlining. Avoid output arguments for returning drop reason where possible - Rework drop handling within qdiscs to include more metadata about the reason and dropping qdisc in the tracepoints - Remove the rtnl_lock use from IP Multicast Routing - Pack size information into the Rx Flow Steering table pointer itself. This allows making the table itself a flat array of u32s, thus making the table allocation size a power of two - Report TCP delayed ack timer information via socket diag - Add ip_local_port_step_width sysctl to allow distributing the randomly selected ports more evenly throughout the allowed space - Add support for per-route tunsrc in IPv6 segment routing - Start work of switching sockopt handling to iov_iter - Improve dynamic recvbuf sizing in MPTCP, limit burstiness and avoid buffer size drifting up - Support MSG_EOR in MPTCP - Add stp_mode attribute to the bridge driver for STP mode selection. This addresses concerns about call_usermodehelper() usage - Remove UDP-Lite support (as announced in 2023) - Remove support for building IPv6 as a module. Remove the now unnecessary function calling indirection Cross-tree stuff: - Move Michael MIC code from generic crypto into wireless, it's considered insecure but some WiFi networks still need it Netfilter: - Switch nft_fib_ipv6 module to no longer need temporary dst_entry object allocations by using fib6_lookup() + RCU. Florian W reports this gets us ~13% higher packet rate - Convert IPVS's global __ip_vs_mutex to per-net service_mutex and switch the service tables to be per-net. Convert some code that walks the service lists to use RCU instead of the service_mutex - Add more opinionated input validation to lower security exposure - Make IPVS hash tables to be per-netns and resizable Wireless: - Finished assoc frame encryption/EPPKE/802.1X-over-auth - Radar detection improvements - Add 6 GHz incumbent signal detection APIs - Multi-link support for FILS, probe response templates and client probing - New APIs and mac80211 support for NAN (Neighbor Aware Networking, aka Wi-Fi Aware) so less work must be in firmware Driver API: - Add numerical ID for devlink instances (to avoid having to create fake bus/device pairs just to have an ID). Support shared devlink instances which span multiple PFs - Add standard counters for reporting pause storm events (implement in mlx5 and fbnic) - Add configuration API for completion writeback buffering (implement in mana) - Support driver-initiated change of RSS context sizes - Support DPLL monitoring input frequency (implement in zl3073x) - Support per-port resources in devlink (implement in mlx5) Misc: - Expand the YAML spec for Netfilter Drivers - Software: - macvlan: support multicast rx for bridge ports with shared source MAC address - team: decouple receive and transmit enablement for IEEE 802.3ad LACP "independent control" - Ethernet high-speed NICs: - nVidia/Mellanox: - support high order pages in zero-copy mode (for payload coalescing) - support multiple packets in a page (for systems with 64kB pages) - Broadcom 25-400GE (bnxt): - implement XDP RSS hash metadata extraction - add software fallback for UDP GSO, lowering the IOMMU cost - Broadcom 800GE (bnge): - add link status and configuration handling - add various HW and SW statistics - Marvell/Cavium: - NPC HW block support for cn20k - Huawei (hinic3): - add mailbox / control queue - add rx VLAN offload - add driver info and link management - Ethernet NICs: - Marvell/Aquantia: - support reading SFP module info on some AQC100 cards - Realtek PCI (r8169): - add support for RTL8125cp - Realtek USB (r8152): - support for the RTL8157 5Gbit chip - add 2500baseT EEE status/configuration support - Ethernet NICs embedded and off-the-shelf IP: - Synopsys (stmmac): - cleanup and reorganize SerDes handling and PCS support - cleanup descriptor handling and per-platform data - cleanup and consolidate MDIO defines and handling - shrink driver memory use for internal structures - improve Tx IRQ coalescing - improve TCP segmentation handling - add support for Spacemit K3 - Cadence (macb): - support PHYs that have inband autoneg disabled with GEM - support IEEE 802.3az EEE - rework usrio capabilities and handling - AMD (xgbe): - improve power management for S0i3 - improve TX resilience for link-down handling - Virtual: - Google cloud vNIC: - support larger ring sizes in DQO-QPL mode - improve HW-GRO handling - support UDP GSO for DQO format - PCIe NTB: - support queue count configuration - Ethernet PHYs: - automatically disable PHY autonomous EEE if MAC is in charge - Broadcom: - add BCM84891/BCM84892 support - Micrel: - support for LAN9645X internal PHY - Realtek: - add RTL8224 pair order support - support PHY LEDs on RTL8211F-VD - support spread spectrum clocking (SSC) - Maxlinear: - add PHY-level statistics via ethtool - Ethernet switches: - Maxlinear (mxl862xx): - support for bridge offloading - support for VLANs - support driver statistics - Bluetooth: - large number of fixes and new device IDs - Mediatek: - support MT6639 (MT7927) - support MT7902 SDIO - WiFi: - Intel (iwlwifi): - UNII-9 and continuing UHR work - MediaTek (mt76): - mt7996/mt7925 MLO fixes/improvements - mt7996 NPU support (HW eth/wifi traffic offload) - Qualcomm (ath12k): - monitor mode support on IPQ5332 - basic hwmon temperature reporting - support IPQ5424 - Realtek: - add USB RX aggregation to improve performance - add USB TX flow control by tracking in-flight URBs - Cellular: - IPA v5.2 support" * tag 'net-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1561 commits) net: pse-pd: fix kernel-doc function name for pse_control_find_by_id() wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit wireguard: allowedips: remove redundant space tools: ynl: add sample for wireguard wireguard: allowedips: Use kfree_rcu() instead of call_rcu() MAINTAINERS: Add netkit selftest files selftests/net: Add additional test coverage in nk_qlease selftests/net: Split netdevsim tests from HW tests in nk_qlease tools/ynl: Make YnlFamily closeable as a context manager net: airoha: Add missing PPE configurations in airoha_ppe_hw_init() net: airoha: Fix VIP configuration for AN7583 SoC net: caif: clear client service pointer on teardown net: strparser: fix skb_head leak in strp_abort_strp() net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete() selftests/bpf: add test for xdp_master_redirect with bond not up net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master net: airoha: Remove PCE_MC_EN_MASK bit in REG_FE_PCE_CFG configuration sctp: disable BH before calling udp_tunnel_xmit_skb() sctp: fix missing encap_port propagation for GSO fragments net: airoha: Rely on net_device pointer in ETS callbacks ... 
Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Support HW queue leasing, allowing containers to be granted access
     to HW queues for zero-copy operations and AF_XDP

   - Number of code moves to help the compiler with inlining. Avoid
     output arguments for returning drop reason where possible

   - Rework drop handling within qdiscs to include more metadata about
     the reason and dropping qdisc in the tracepoints

   - Remove the rtnl_lock use from IP Multicast Routing

   - Pack size information into the Rx Flow Steering table pointer
     itself. This allows making the table itself a flat array of u32s,
     thus making the table allocation size a power of two

   - Report TCP delayed ack timer information via socket diag

   - Add ip_local_port_step_width sysctl to allow distributing the
     randomly selected ports more evenly throughout the allowed space

   - Add support for per-route tunsrc in IPv6 segment routing

   - Start work of switching sockopt handling to iov_iter

   - Improve dynamic recvbuf sizing in MPTCP, limit burstiness and avoid
     buffer size drifting up

   - Support MSG_EOR in MPTCP

   - Add stp_mode attribute to the bridge driver for STP mode selection.
     This addresses concerns about call_usermodehelper() usage

   - Remove UDP-Lite support (as announced in 2023)

   - Remove support for building IPv6 as a module. Remove the now
     unnecessary function calling indirection

  Cross-tree stuff:

   - Move Michael MIC code from generic crypto into wireless, it's
     considered insecure but some WiFi networks still need it

  Netfilter:

   - Switch nft_fib_ipv6 module to no longer need temporary dst_entry
     object allocations by using fib6_lookup() + RCU.

     Florian W reports this gets us ~13% higher packet rate

   - Convert IPVS's global __ip_vs_mutex to per-net service_mutex and
     switch the service tables to be per-net. Convert some code that
     walks the service lists to use RCU instead of the service_mutex

   - Add more opinionated input validation to lower security exposure

   - Make IPVS hash tables to be per-netns and resizable

  Wireless:

   - Finished assoc frame encryption/EPPKE/802.1X-over-auth

   - Radar detection improvements

   - Add 6 GHz incumbent signal detection APIs

   - Multi-link support for FILS, probe response templates and client
     probing

   - New APIs and mac80211 support for NAN (Neighbor Aware Networking,
     aka Wi-Fi Aware) so less work must be in firmware

  Driver API:

   - Add numerical ID for devlink instances (to avoid having to create
     fake bus/device pairs just to have an ID). Support shared devlink
     instances which span multiple PFs

   - Add standard counters for reporting pause storm events (implement
     in mlx5 and fbnic)

   - Add configuration API for completion writeback buffering (implement
     in mana)

   - Support driver-initiated change of RSS context sizes

   - Support DPLL monitoring input frequency (implement in zl3073x)

   - Support per-port resources in devlink (implement in mlx5)

  Misc:

   - Expand the YAML spec for Netfilter

  Drivers

   - Software:
      - macvlan: support multicast rx for bridge ports with shared
        source MAC address
      - team: decouple receive and transmit enablement for IEEE 802.3ad
        LACP "independent control"

   - Ethernet high-speed NICs:
      - nVidia/Mellanox:
         - support high order pages in zero-copy mode (for payload
           coalescing)
         - support multiple packets in a page (for systems with 64kB
           pages)
      - Broadcom 25-400GE (bnxt):
         - implement XDP RSS hash metadata extraction
         - add software fallback for UDP GSO, lowering the IOMMU cost
      - Broadcom 800GE (bnge):
         - add link status and configuration handling
         - add various HW and SW statistics
      - Marvell/Cavium:
         - NPC HW block support for cn20k
      - Huawei (hinic3):
         - add mailbox / control queue
         - add rx VLAN offload
         - add driver info and link management

   - Ethernet NICs:
      - Marvell/Aquantia:
         - support reading SFP module info on some AQC100 cards
      - Realtek PCI (r8169):
         - add support for RTL8125cp
      - Realtek USB (r8152):
         - support for the RTL8157 5Gbit chip
         - add 2500baseT EEE status/configuration support

   - Ethernet NICs embedded and off-the-shelf IP:
      - Synopsys (stmmac):
         - cleanup and reorganize SerDes handling and PCS support
         - cleanup descriptor handling and per-platform data
         - cleanup and consolidate MDIO defines and handling
         - shrink driver memory use for internal structures
         - improve Tx IRQ coalescing
         - improve TCP segmentation handling
         - add support for Spacemit K3
      - Cadence (macb):
         - support PHYs that have inband autoneg disabled with GEM
         - support IEEE 802.3az EEE
         - rework usrio capabilities and handling
      - AMD (xgbe):
         - improve power management for S0i3
         - improve TX resilience for link-down handling

   - Virtual:
      - Google cloud vNIC:
         - support larger ring sizes in DQO-QPL mode
         - improve HW-GRO handling
         - support UDP GSO for DQO format
      - PCIe NTB:
         - support queue count configuration

   - Ethernet PHYs:
      - automatically disable PHY autonomous EEE if MAC is in charge
      - Broadcom:
         - add BCM84891/BCM84892 support
      - Micrel:
         - support for LAN9645X internal PHY
      - Realtek:
         - add RTL8224 pair order support
         - support PHY LEDs on RTL8211F-VD
         - support spread spectrum clocking (SSC)
      - Maxlinear:
         - add PHY-level statistics via ethtool

   - Ethernet switches:
      - Maxlinear (mxl862xx):
         - support for bridge offloading
         - support for VLANs
         - support driver statistics

   - Bluetooth:
      - large number of fixes and new device IDs
      - Mediatek:
         - support MT6639 (MT7927)
         - support MT7902 SDIO

   - WiFi:
      - Intel (iwlwifi):
         - UNII-9 and continuing UHR work
      - MediaTek (mt76):
         - mt7996/mt7925 MLO fixes/improvements
         - mt7996 NPU support (HW eth/wifi traffic offload)
      - Qualcomm (ath12k):
         - monitor mode support on IPQ5332
         - basic hwmon temperature reporting
         - support IPQ5424
      - Realtek:
         - add USB RX aggregation to improve performance
         - add USB TX flow control by tracking in-flight URBs

   - Cellular:
      - IPA v5.2 support"

* tag 'net-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1561 commits)
  net: pse-pd: fix kernel-doc function name for pse_control_find_by_id()
  wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit
  wireguard: allowedips: remove redundant space
  tools: ynl: add sample for wireguard
  wireguard: allowedips: Use kfree_rcu() instead of call_rcu()
  MAINTAINERS: Add netkit selftest files
  selftests/net: Add additional test coverage in nk_qlease
  selftests/net: Split netdevsim tests from HW tests in nk_qlease
  tools/ynl: Make YnlFamily closeable as a context manager
  net: airoha: Add missing PPE configurations in airoha_ppe_hw_init()
  net: airoha: Fix VIP configuration for AN7583 SoC
  net: caif: clear client service pointer on teardown
  net: strparser: fix skb_head leak in strp_abort_strp()
  net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()
  selftests/bpf: add test for xdp_master_redirect with bond not up
  net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master
  net: airoha: Remove PCE_MC_EN_MASK bit in REG_FE_PCE_CFG configuration
  sctp: disable BH before calling udp_tunnel_xmit_skb()
  sctp: fix missing encap_port propagation for GSO fragments
  net: airoha: Rely on net_device pointer in ETS callbacks
  ...
af_packet: convert to getsockopt_iter 2026-04-13T21:56:29+00:00 Breno Leitao leitao@debian.org 2026-04-08T10:30:31+00:00 9c99d62705692db7fc8b8921efa0db189e84e694 Convert AF_PACKET's getsockopt implementation to use the new getsockopt_iter callback with sockopt_t. Key changes: - Replace (char __user *optval, int __user *optlen) with sockopt_t *opt - Use opt->optlen for buffer length (input) and returned size (output) - Use copy_to_iter() instead of put_user()/copy_to_user() - For PACKET_HDRLEN which reads from optval: use opt->iter_in with copy_from_iter() for the input read, then the common opt->iter_out copy_to_iter() epilogue handles the output Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20260408-getsockopt-v3-3-061bb9cb355d@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Convert AF_PACKET's getsockopt implementation to use the new
getsockopt_iter callback with sockopt_t.

Key changes:
- Replace (char __user *optval, int __user *optlen) with sockopt_t *opt
- Use opt->optlen for buffer length (input) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- For PACKET_HDRLEN which reads from optval: use opt->iter_in with
  copy_from_iter() for the input read, then the common opt->iter_out
  copy_to_iter() epilogue handles the output

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260408-getsockopt-v3-3-061bb9cb355d@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>