linux.git/net/ipv4, branch master

Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2026-07-25T02:31:12+00:00

Pull bpf fixes from Eduard Zingerman:

 - Fix tcp_bpf_sendmsg() error path mistaking a concurrently-freed
   sk_psock->cork for the local temporary message and freeing it again
   (Chengfeng Ye)

 - Reject passing scalar NULL to nonnull arg of a global subprog.

   Previously the verifier did not account for the cases directly
   passing scalars to a global subprog, e.g.: 'global_func(0);' would
   pass even if 'global_func' argument was marked nonnull (Amery Hung)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()
  selftests/bpf: Test passing scalar NULL to nonnull global subprog
  bpf: Reject passing scalar NULL to nonnull arg of a global subprog

bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()

2026-07-24T22:04:11+00:00

tcp_bpf_sendmsg() keeps msg_tx across sk_stream_wait_memory(), which
drops and reacquires the socket lock.  Its error path tries to decide
whether msg_tx names the local temporary message by comparing it with
the current value of psock->cork.

This comparison is unsafe when two threads send on the same socket:

  Thread A                         Thread B
  msg_tx = psock->cork
  sk_msg_alloc() fails
  sk_stream_wait_memory()
    releases the socket lock      acquires the socket lock
                                  completes the cork
                                  psock->cork = NULL
                                  frees the cork
    reacquires the socket lock
  msg_tx != psock->cork
  sk_msg_free(msg_tx)

The stale cork is therefore mistaken for the local temporary message
and freed again.  KASAN reported:

  BUG: KASAN: slab-use-after-free in sk_msg_free+0x49/0x50
  Read of size 4 at addr ffff88810c908800 by task poc/90
  Call Trace:
   sk_msg_free+0x49/0x50
   tcp_bpf_sendmsg+0x14f5/0x1cc0
   __sys_sendto+0x32c/0x3a0
   __x64_sys_sendto+0xdb/0x1b0
  Allocated by task 89:
   __kasan_kmalloc+0x8f/0xa0
   tcp_bpf_sendmsg+0x16b3/0x1cc0
  Freed by task 91:
   __kasan_slab_free+0x43/0x70
   kfree+0x131/0x3c0
   tcp_bpf_sendmsg+0xec3/0x1cc0

msg_tx can only name the stack-local tmp or the shared cork. Check for
tmp directly so a changed psock->cork cannot turn a shared message into
an apparent local one.

Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Chengfeng Ye 
Reviewed-by: Emil Tsalapatis 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/87fr18lmzo.fsf%40cloudflare.com/
Link: https://lore.kernel.org/netdev/20260719161630.2901208-1-nicoyip.dev%40gmail.com/ [v1]
Link: https://patch.msgid.link/20260724103856.3399001-1-nicoyip.dev@gmail.com
Signed-off-by: Eduard Zingerman

Merge tag 'net-7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-07-23T19:58:08+00:00

Pull networking fixes from Jakub Kicinski:
 "Lots of fixes, double the count even for the 'new normal'. Largely due
  to my time off followed by a networking conference which distracted
  most maintainers (less so the AI generators).

  Including fixes from Bluetooth and WiFi.

  Current release - regressions:

   - wifi: mt76: fix MAC address for non OF pcie cards

  Current release - new code bugs:

   - mptcp: fix BUILD_BUG_ON on legacy ARM config

   - wifi: cfg80211: guard optional PMSR nominal time

  Previous releases - regressions:

   - qrtr: ns: raise node count limit to 512, we arbitrarily picked
     256 as a limit, turns out it was too low for real world deployments

   - vhost-net: fix TX stall when vhost owns virtio-net header

   - eth: amd-xgbe: fix MAC_AUTO_SW handling in CL37 AN

   - wifi: ath12k: fix low MLO RX throughput on WCN7850

  Previous releases - always broken:

   - number of random AI fixes for SCTP, RDS and TIPC protocols

   - more AI-looking fixes for WiFi drivers

   - number of fixes for missing pointer reloading after skb pull

   - reject BPF redirect use from qdisc qevent block

   - tcp: initialize standalone TCP-AO response padding

   - vsock/virtio: collapse receive queue under memory pressure to avoid
     client OOMing the host with tiny messages

   - ipv4: icmp: fill flow parameters in icmp_route_lookup decoy lookup,
     make sure the ICMP response routing follows the routing policy

   - gro: fix double aggregation of flush-marked skbs

   - ovpn: fix various refcount bugs

   - tls: device: push pending open record on splice EOF

   - eth: mlx5:
      - use sender devcom for MPV master-up
      - fix MCIA register buffer overflow on 32 dword reads"

* tag 'net-7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (234 commits)
  drop_monitor: perform u64_stats updates under IRQ-disabled section
  drop_monitor: fix size calculations for 64-bit attributes
  net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD
  mptcp: fix BUILD_BUG_ON on legacy ARM config
  selftests: mptcp: userspace_pm: fix undefined variable port
  mptcp: fix stale skb->sk reference on subflow close
  mptcp: pm: userspace: fix use-after-free in get_local_id
  mptcp: decrement subflows counter on failed passive join
  mac802154: hold an interface reference across the scan worker
  sctp: don't free the ASCONF's own transport in DEL-IP processing
  phonet: check register_netdevice_notifier() error in phonet_device_init()
  phonet: pep: fix use-after-free in pep_get_sb()
  bnge/bng_re: fix ring ID widths
  tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()
  net: airoha: fix ETS channel derivation in airoha_tc_setup_qdisc_ets()
  mctp: check register_netdevice_notifier() error in mctp_device_init()
  ptp: netc: explicitly clear TMR_OFF during initialization
  rds: tcp: unregister sysctl before tearing down listen socket
  ipv6: Change allocation flags to match rcu_read_lock section requirements
  net: slip: serialize receive against buffer reallocation
  ...

tcp: challenge ACK for non-exact RST in SYN-RECEIVED

2026-07-23T15:27:22+00:00

The SYN-RECEIVED request-socket path in tcp_check_req() accepts an
in-window RST without requiring SEG.SEQ to exactly match RCV.NXT.  A
non-exact RST therefore removes the request instead of eliciting a
challenge ACK.

RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in
SYN-RECEIVED: an exact RST resets the connection, while a non-exact
in-window RST must trigger a challenge ACK and be dropped.

Apply that check before the ACK-field validation, following the RFC
sequence-number, RST, then ACK processing order.  Factor the per-netns
challenge ACK quota out of tcp_send_challenge_ack() so request sockets
can share it.  Use the request socket's send_ack() callback and its own
out-of-window ACK timestamp to send and rate-limit the response.

Reported-by: Yuxiang Yang 
Reported-by: Yizhou Zhao 
Reported-by: Ao Wang 
Reported-by: Xuewei Feng 
Reported-by: Qi Li 
Reported-by: Ke Xu 
Fixes: 282f23c6ee34 ("tcp: implement RFC 5961 3.2")
Cc: stable@vger.kernel.org
Signed-off-by: Yuxiang Yang 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20260717081443.809393-2-yangyx22@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski

raw: annotate lockless match fields in raw_v4_match()

2026-07-23T14:46:12+00:00

raw_v4_match() is a lockless match helper under sk_for_each_rcu(). It
still reads inet->inet_daddr, inet->inet_rcv_saddr and
sk->sk_bound_dev_if with plain loads while bind, connect and
bind-to-device paths can update the same match fields concurrently.

Annotate only those mutable match fields in raw_v4_match(), and do so
at the point of use instead of hoisting the bound-device read before
the earlier short-circuit tests.

Also annotate the raw bind writer and the shared IPv4 datagram connect
writer used by raw sockets, so the address fields updated on bind and
connect match explicit WRITE_ONCE() updates.

This version intentionally leaves the shared disconnect-side IPv4
writers to follow-up cleanup and limits the writer changes here to the
raw bind path and the datagram connect path directly exercised by raw
sockets.

Fixes: 0daf07e52709 ("raw: convert raw sockets to RCU")
Signed-off-by: Runyu Xiao 
Link: https://patch.msgid.link/20260716142958.3064224-1-runyu.xiao@seu.edu.cn
Signed-off-by: Jakub Kicinski

ipv4: icmp: fill flow parameters in icmp_route_lookup decoy lookup

2026-07-23T14:01:24+00:00

When Linux forwards a packet and needs to generate an ICMP error,
icmp_route_lookup() performs a reverse-path relookup. For non-local
destinations, it performs a decoy lookup to find the expected egress
interface (rt2->dst.dev) before validating the path with ip_route_input().

Currently, the decoy flow structure (fl4_2) only sets .daddr = fl4_dec.saddr,
leaving .saddr, .flowi4_dscp, .flowi4_proto, .flowi4_mark, .flowi4_oif,
.fl4_sport, .fl4_dport, and .flowi4_uid zeroed out.

When policy routing rules (such as ip rule add from $SRC lookup 100, or
dscp/fwmark/ipproto/port rules, or VRF bindings) are configured:
1. The decoy lookup fails to match the policy rule because saddr and other
   key flow selectors are missing in fl4_2.
2. It resolves a route using the default table instead, returning an incorrect
   egress netdev.
3. Passing the wrong netdev to ip_route_input() causes strict reverse-path
   filtering (rp_filter=1) to fail, logging false-positive "martian source"
   warnings and causing the relookup to fail.

Fix this by initializing fl4_2 from fl4_dec and:
- Swapping source/destination IP addresses.
- Swapping L4 ports for transport protocols with ports (TCP, UDP, SCTP, DCCP)
  so port-based policy routing matches correctly. Non-port protocols (such as
  ICMP or GRE) leave the flowi_uli union fields intact to prevent corruption.
- Setting .flowi4_oif = l3mdev_master_ifindex(route_lookup_dev) to ensure
  VRF routing tables are respected.
- Setting .flowi4_flags |= FLOWI_FLAG_ANYSRC to allow output route lookups
  for non-local source IP addresses.
- Using __ip_route_output_key() instead of ip_route_output_key() for fl4_2
  so that raw FIB routing is used without triggering spurious XFRM policy
  lookups on the decoy flow (the actual XFRM lookup is performed later using
  fl4_dec).

Fixes: 415b3334a21a ("icmp: Fix regression in nexthop resolution during replies.")
Reported-by: Muhammad Ziad 
Closes: https://lore.kernel.org/netdev/CAOAwikA60AYKdFr_UDLyja3oU4hqyAE7uFZWqum5uRdaQsgRYg@mail.gmail.com/
Signed-off-by: Eric Dumazet 
Reviewed-by: David Ahern 
Link: https://patch.msgid.link/20260722104236.2938082-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: gre: fix lltx regression for GRE tunnels with SEQ/CSUM

2026-07-23T11:01:57+00:00

Before commit 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to
dev->lltx"), NETIF_F_LLTX was set unconditionally in both
__gre_tunnel_init() and ip6gre_tnl_init_features() alongside
GRE_FEATURES:

    dev->features |= GRE_FEATURES | NETIF_F_LLTX;

When that commit converted NETIF_F_LLTX to the dev->lltx flag, it
placed 'dev->lltx = true' after the SEQ/CSUM early returns instead
of before them. This causes GRE/GRETAP/ip6gre tunnels with SEQ or
CSUM+encap to lose lockless TX, reintroducing _xmit_lock acquisition
around their ndo_start_xmit. Since GRE xmit re-enters the stack via
ip_tunnel_xmit(), holding _xmit_lock risks ABBA deadlock with the
underlay device.

  CPU0                        CPU1
  ----                        ----
  lock(&qdisc_xmit_lock_key#6);
                              lock(&qdisc_xmit_lock_key#3);
                              lock(&qdisc_xmit_lock_key#6);
  lock(&qdisc_xmit_lock_key#3);

Fix by moving dev->lltx = true before the early returns in both
functions, restoring the original unconditional behavior.

Fixes: 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx")
Signed-off-by: Yun Zhou 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20260713150945.1779628-1-yun.zhou@windriver.com
Signed-off-by: Paolo Abeni

bpf: tcp: fix double sock release on batch realloc

2026-07-23T10:20:34+00:00

bpf_iter_tcp_batch() releases the current batch via
bpf_iter_tcp_put_batch(), which drops the socket refs and rewrites
each slot with the socket cookie, then grows the batch. cur_sk/end_sk
are kept for bpf_iter_tcp_resume(), but on realloc failure the function
returns ERR_PTR() before resume runs, leaving cur_sk < end_sk over
slots that now hold cookies rather than sock pointers.
bpf_iter_tcp_seq_stop() then calls bpf_iter_tcp_put_batch() again and
dereferences a cookie as a struct sock.

Empty the batch on the failure path so stop() does not release it
again. The sockets were already freed by the first
bpf_iter_tcp_put_batch(), so nothing leaks, and a later read() rescans
the bucket from the start instead of skipping it. The sibling
GFP_NOWAIT failure path still holds real socket references and is left
for stop() to release.

  BUG: KASAN: null-ptr-deref in __sock_gen_cookie
  Read of size 8 at addr 0000000000000059 by task exploit
   ...
   __sock_gen_cookie (net/core/sock_diag.c:28)
   bpf_iter_tcp_put_batch (net/ipv4/tcp_ipv4.c:2918)
   bpf_iter_tcp_seq_stop (net/ipv4/tcp_ipv4.c:3270)
   bpf_seq_read (kernel/bpf/bpf_iter.c:205)
   vfs_read (fs/read_write.c:572)
   ksys_read (fs/read_write.c:716)
   do_syscall_64
   entry_SYSCALL_64_after_hwframe
  Kernel panic - not syncing: Fatal exception

Fixes: cdec67a489d4 ("bpf: tcp: Make sure iter->batch always contains a full bucket snapshot")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) 
Reviewed-by: Eric Dumazet 
Reviewed-by: Jordan Rife 
Link: https://patch.msgid.link/20260713233230.3553593-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni

tcp: initialize standalone TCP-AO response padding

2026-07-21T22:24:36+00:00

tcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP
responses with TCP-AO options.  The option length carries the actual MAC
length, but the TCP header length includes the option rounded up to a
four-byte boundary.

tcp_ao_hash_hdr() writes the MAC only.  Thus, when the MAC length is not
four-byte aligned, the one to three bytes after the MAC are left
uninitialized and may be transmitted.  For the normal TCP-AO hashing
mode, those bytes also have to be initialized before computing the MAC.

Initialize only the alignment padding in the TCP-AO branches, before
hashing the header.  Use TCPOPT_NOP, as in the normal TCP-AO output path.
This avoids adding work to non-AO TCP responses while preserving a valid
authenticated header.

Fixes: decde2586b34 ("net/tcp: Add TCP-AO sign to twsk")
Fixes: da7dfaa6d6f7 ("net/tcp: Consistently align TCP-AO option in the header")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao 
Reported-by: Yuxiang Yang 
Reported-by: Ao Wang 
Reported-by: Xuewei Feng 
Reported-by: Qi Li 
Reported-by: Ke Xu 
Suggested-by: Eric Dumazet 
Signed-off-by: Yizhou Zhao 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20260713105631.8616-1-zhaoyz24@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski

nexthop: initialize extack in nh_res_bucket_migrate()

2026-07-21T22:09:41+00:00

nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to
call_nexthop_res_bucket_notifiers(). When
nh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns
-ENOMEM), the error is propagated back before any notifier sets
extack._msg, and the error path formats the stale pointer with
pr_err_ratelimited("%s\n", extack._msg). With CONFIG_INIT_STACK_NONE
this dereferences uninitialized stack memory:

  Oops: general protection fault, probably for non-canonical address ...
  KASAN: maybe wild-memory-access in range [...]
  RIP: 0010:string (lib/vsprintf.c:730)
   vsnprintf (lib/vsprintf.c:2945)
   _printk (kernel/printk/printk.c:2504)
   nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)
   nh_res_table_upkeep (net/ipv4/nexthop.c:1866)
   rtm_new_nexthop (net/ipv4/nexthop.c:3323)
   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
   netlink_sendmsg (net/netlink/af_netlink.c:1900)
  Kernel panic - not syncing: Fatal exception

Zero-initialize extack so _msg is NULL on error paths that never set it.

Fixes: 7c37c7e00411 ("nexthop: Implement notifiers for resilient nexthop groups")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20260713221551.3344650-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski