Commit Graph

82211 Commits

Author SHA1 Message Date
Ido Schimmel
d12d04d221 ipv6: icmp: Add RFC 5837 support
Add the ability to append the incoming IP interface information to
ICMPv6 error messages in accordance with RFC 5837 and RFC 4884. This is
required for more meaningful traceroute results in unnumbered networks.

The feature is disabled by default and controlled via a new sysctl
("net.ipv6.icmp.errors_extension_mask") which accepts a bitmask of ICMP
extensions to append to ICMP error messages. Currently, only a single
value is supported, but the interface and the implementation should be
able to support more extensions, if needed.

Clone the skb and copy the relevant data portions before modifying the
skb as the caller of icmp6_send() still owns the skb after the function
returns. This should be fine since by default ICMP error messages are
rate limited to 1000 per second and no more than 1 per second per
specific host.

Trim or pad the packet to 128 bytes before appending the ICMP extension
structure in order to be compatible with legacy applications that assume
that the ICMP extension structure always starts at this offset (the
minimum length specified by RFC 4884).

Since commit 20e1954fe2 ("ipv6: RFC 4884 partial support for SIT/GRE
tunnels") it is possible for icmp6_send() to be called with an skb that
already contains ICMP extensions. This can happen when we receive an
ICMPv4 message with extensions from a tunnel and translate it to an
ICMPv6 message towards an IPv6 host in the overlay network. I could not
find an RFC that supports this behavior, but it makes sense to not
overwrite the original extensions that were appended to the packet.
Therefore, avoid appending extensions if the length field in the
provided ICMPv6 header is already filled.

Export netdev_copy_name() using EXPORT_IPV6_MOD_GPL() to make it
available to IPv6 when it is built as a module.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251027082232.232571-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29 18:28:30 -07:00
Ido Schimmel
f0e7036fc9 ipv4: icmp: Add RFC 5837 support
Add the ability to append the incoming IP interface information to
ICMPv4 error messages in accordance with RFC 5837 and RFC 4884. This is
required for more meaningful traceroute results in unnumbered networks.

The feature is disabled by default and controlled via a new sysctl
("net.ipv4.icmp_errors_extension_mask") which accepts a bitmask of ICMP
extensions to append to ICMP error messages. Currently, only a single
value is supported, but the interface and the implementation should be
able to support more extensions, if needed.

Clone the skb and copy the relevant data portions before modifying the
skb as the caller of __icmp_send() still owns the skb after the function
returns. This should be fine since by default ICMP error messages are
rate limited to 1000 per second and no more than 1 per second per
specific host.

Trim or pad the packet to 128 bytes before appending the ICMP extension
structure in order to be compatible with legacy applications that assume
that the ICMP extension structure always starts at this offset (the
minimum length specified by RFC 4884).

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251027082232.232571-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29 18:28:29 -07:00
Kuniyuki Iwashima
b8a7826e4b net: sched: Don't use WARN_ON_ONCE() for -ENOMEM in tcf_classify().
As demonstrated by syzbot, WARN_ON_ONCE() in tcf_classify() can
be easily triggered by fault injection. [0]

We should not use WARN_ON_ONCE() for the simple -ENOMEM case.

Also, we provide SKB_DROP_REASON_NOMEM for the same error.

Let's remove WARN_ON_ONCE() there.

[0]:
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 UID: 0 PID: 31392 Comm: syz.8.7081 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 should_fail_ex+0x414/0x560
 should_failslab+0xa8/0x100
 kmem_cache_alloc_noprof+0x74/0x6e0
 skb_ext_add+0x148/0x8f0
 tcf_classify+0xeba/0x1140
 multiq_enqueue+0xfd/0x4c0 net/sched/sch_multiq.c:66
...
WARNING: CPU: 0 PID: 31392 at net/sched/cls_api.c:1869 tcf_classify+0xfd7/0x1140
Modules linked in:
CPU: 0 UID: 0 PID: 31392 Comm: syz.8.7081 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:tcf_classify+0xfd7/0x1140
Code: e8 03 42 0f b6 04 30 84 c0 0f 85 41 01 00 00 66 41 89 1f eb 05 e8 89 26 75 f8 bb ff ff ff ff e9 04 f9 ff ff e8 7a 26 75 f8 90 <0f> 0b 90 49 83 c5 44 4c 89 eb 49 c1 ed 03 43 0f b6 44 35 00 84 c0
RSP: 0018:ffffc9000b7671f0 EFLAGS: 00010293
RAX: ffffffff894addf6 RBX: 0000000000000002 RCX: ffff888025029e40
RDX: 0000000000000000 RSI: ffffffff8bbf05c0 RDI: ffffffff8bbf0580
RBP: 0000000000000000 R08: 00000000ffffffff R09: 1ffffffff1c0bfd6
R10: dffffc0000000000 R11: fffffbfff1c0bfd7 R12: ffff88805a90de5c
R13: ffff88805a90ddc0 R14: dffffc0000000000 R15: ffffc9000b7672c0
FS:  00007f20739f66c0(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2d2a80 CR3: 0000000024e36000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 multiq_classify net/sched/sch_multiq.c:39 [inline]
 multiq_enqueue+0xfd/0x4c0 net/sched/sch_multiq.c:66
 dev_qdisc_enqueue+0x4e/0x260 net/core/dev.c:4118
 __dev_xmit_skb net/core/dev.c:4214 [inline]
 __dev_queue_xmit+0xe83/0x3b50 net/core/dev.c:4729
 packet_snd net/packet/af_packet.c:3076 [inline]
 packet_sendmsg+0x3e33/0x5080 net/packet/af_packet.c:3108
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f207578efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f20739f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f20759e5fa0 RCX: 00007f207578efc9
RDX: 0000000000000004 RSI: 00002000000000c0 RDI: 0000000000000008
RBP: 00007f20739f6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f20759e6038 R14: 00007f20759e5fa0 R15: 00007f2075b0fa28
 </TASK>

Reported-by: syzbot+87e1289a044fcd0c5f62@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69003e33.050a0220.32483.00e8.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251028035859.2067690-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29 18:00:37 -07:00
Wang Liang
f58abec23d net: ipv4: Remove extern udp_v4_early_demux()/tcp_v4_early_demux() in .c files
Function udp_v4_early_demux() was already declared in 'include/net/udp.h',
no need to keep the extern in 'ip_input.c', which may produce the
following checkpatch warning:

  WARNING: externs should be avoided in .c files
  #45: FILE: net/ipv4/ip_input.c:322:
  +enum skb_drop_reason udp_v4_early_demux(struct sk_buff *skb);

Replace it by including 'net/udp.h'. Do the same for tcp_v4_early_demux().

Signed-off-by: Wang Liang <wangliang74@huawei.com>
Link: https://patch.msgid.link/20251025092637.1020960-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29 17:05:30 -07:00
Rakuram Eswaran
5c00da851c net: tcp_lp: fix kernel-doc warnings and update outdated reference links
Fix kernel-doc warnings in tcp_lp.c by adding missing parameter
descriptions for tcp_lp_cong_avoid() and tcp_lp_pkts_acked() when
building with W=1.

Also replace invalid URLs in the file header comment with the currently
valid links to the TCP-LP paper and implementation page.

No functional changes.

Signed-off-by: Rakuram Eswaran <rakuram.e96@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251025-net_ipv4_tcp_lp_c-v1-1-058cc221499e@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-28 17:52:44 -07:00
Christophe JAILLET
294bfe0343 sctp: Constify struct sctp_sched_ops
'struct sctp_sched_ops' is not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   8019	    568	      0	   8587	   218b	net/sctp/stream_sched_fc.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   8275	    312	      0	   8587	   218b	net/sctp/stream_sched_fc.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://patch.msgid.link/dce03527eb7b7cc8a3c26d5cdac12bafe3350135.1761377890.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-28 17:50:55 -07:00
Eric Dumazet
a086e9860c net: optimize enqueue_to_backlog() for the fast path
Add likely() and unlikely() clauses for the common cases:

Device is running.
Queue is not full.
Queue is less than half capacity.

Add max_backlog parameter to skb_flow_limit() to avoid
a second READ_ONCE(net_hotdata.max_backlog).

skb_flow_limit() does not need the backlog_lock protection,
and can be called before we acquire the lock, for even better
resistance to attacks.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251024090517.3289181-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-28 17:39:03 -07:00
Eric Dumazet
0ae1ac7335 tcp: remove one ktime_get() from recvmsg() fast path
Each time some payload is consumed by user space (recvmsg() and friends),
TCP calls tcp_rcv_space_adjust() to run DRS algorithm to check
if an increase of sk->sk_rcvbuf is needed.

This function is based on time sampling, and currently calls
tcp_mstamp_refresh(tp), which is a wrapper around ktime_get_ns().

ktime_get_ns() has a high cost on some platforms.
100+ cycles for rdtscp on AMD EPYC Turin for instance.

We do not have to refresh tp->tcp_mpstamp, using the last cached value
is enough. We only need to refresh it from __tcp_cleanup_rbuf()
if an ACK must be sent (this is a rare event).

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251024120707.3516550-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:15:38 -07:00
Kuniyuki Iwashima
71068e2e1b sctp: Remove sctp_copy_sock() and sctp_copy_descendant().
Now, sctp_accept() and sctp_do_peeloff() use sk_clone(), and
we no longer need sctp_copy_sock() and sctp_copy_descendant().

Let's remove them.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-9-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:59 -07:00
Kuniyuki Iwashima
b7ddb55f31 sctp: Use sctp_clone_sock() in sctp_do_peeloff().
sctp_do_peeloff() calls sock_create() to allocate and initialise
struct sock, inet_sock, and sctp_sock, but later sctp_copy_sock()
and sctp_sock_migrate() overwrite most fields.

What sctp_do_peeloff() does is more like accept().

Let's use sock_create_lite() and sctp_clone_sock().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-8-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:58 -07:00
Kuniyuki Iwashima
c49ed521f1 sctp: Remove sctp_pf.create_accept_sk().
sctp_v[46]_create_accept_sk() are no longer used.

Let's remove sctp_pf.create_accept_sk().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-7-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:58 -07:00
Kuniyuki Iwashima
16942cf4d3 sctp: Use sk_clone() in sctp_accept().
sctp_accept() calls sctp_v[46]_create_accept_sk() to allocate a new
socket and calls sctp_sock_migrate() to copy fields from the parent
socket to the new socket.

sctp_v4_create_accept_sk() allocates sk by sk_alloc(), initialises
it by sock_init_data(), and copy a bunch of fields from the parent
socekt by sctp_copy_sock().

sctp_sock_migrate() calls sctp_copy_descendant() to copy most fields
in sctp_sock from the parent socket by memcpy().

These can be simply replaced by sk_clone().

Let's consolidate sctp_v[46]_create_accept_sk() to sctp_clone_sock()
with sk_clone().

We will reuse sctp_clone_sock() for sctp_do_peeloff() and then remove
sctp_copy_descendant().

Note that sock_reset_flag(newsk, SOCK_ZAPPED) is not copied to
sctp_clone_sock() as sctp does not use SOCK_ZAPPED at all.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:58 -07:00
Kuniyuki Iwashima
151b98d10e net: Add sk_clone().
sctp_accept() will use sk_clone_lock(), but it will be called
with the parent socket locked, and sctp_migrate() acquires the
child lock later.

Let's add no lock version of sk_clone_lock().

Note that lockdep complains if we simply use bh_lock_sock_nested().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-5-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:57 -07:00
Kuniyuki Iwashima
b7185792f8 sctp: Don't call sk->sk_prot->init() in sctp_v[46]_create_accept_sk().
sctp_accept() calls sctp_v[46]_create_accept_sk() to allocate a new
socket and calls sctp_sock_migrate() to copy fields from the parent
socket to the new socket.

sctp_v[46]_create_accept_sk() calls sctp_init_sock() to initialise
sctp_sock, but most fields are overwritten by sctp_copy_descendant()
called from sctp_sock_migrate().

Things done in sctp_init_sock() but not in sctp_sock_migrate() are
the following:

  1. Copy sk->sk_gso
  2. Copy sk->sk_destruct (sctp_v6_init_sock())
  3. Allocate sctp_sock.ep
  4. Initialise sctp_sock.pd_lobby
  5. Count sk_sockets_allocated_inc(), sock_prot_inuse_add(),
     and SCTP_DBG_OBJCNT_INC()

Let's do these in sctp_copy_sock() and sctp_sock_migrate() and avoid
calling sk->sk_prot->init() in sctp_v[46]_create_accept_sk().

Note that sk->sk_destruct is already copied in sctp_copy_sock().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-4-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:57 -07:00
Kuniyuki Iwashima
2d4df59aae sctp: Don't copy sk_sndbuf and sk_rcvbuf in sctp_sock_migrate().
sctp_sock_migrate() is called from 2 places.

1) sctp_accept() calls sp->pf->create_accept_sk() before
   sctp_sock_migrate(), and sp->pf->create_accept_sk() calls
   sctp_copy_sock().

2) sctp_do_peeloff() also calls sctp_copy_sock() before
   sctp_sock_migrate().

sctp_copy_sock() copies sk_sndbuf and sk_rcvbuf from the
parent socket.

Let's not copy the two fields in sctp_sock_migrate().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:57 -07:00
Kuniyuki Iwashima
622e8838a2 sctp: Defer SCTP_DBG_OBJCNT_DEC() to sctp_destroy_sock().
SCTP_DBG_OBJCNT_INC() is called only when sctp_init_sock()
returns 0 after successfully allocating sctp_sk(sk)->ep.

OTOH, SCTP_DBG_OBJCNT_DEC() is called in sctp_close().

The code seems to expect that the socket is always exposed
to userspace once SCTP_DBG_OBJCNT_INC() is incremented, but
there is a path where the assumption is not true.

In sctp_accept(), sctp_sock_migrate() could fail after
sctp_init_sock().

Then, sk_common_release() does not call inet_release() nor
sctp_close().  Instead, it calls sk->sk_prot->destroy().

Let's move SCTP_DBG_OBJCNT_DEC() from sctp_close() to
sctp_destroy_sock().

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:04:56 -07:00
Jakub Kicinski
bbfa5e7c8d Merge tag 'batadv-next-pullrequest-20251024' of https://git.open-mesh.org/linux-merge
Simon Wunderlich says:

====================
This cleanup patchset includes the following patches:

 - bump version strings, by Simon Wunderlich

 - use skb_crc32c() instead of skb_seq_read(), by Sven Eckelmann

* tag 'batadv-next-pullrequest-20251024' of https://git.open-mesh.org/linux-merge:
  batman-adv: use skb_crc32c() instead of skb_seq_read()
  batman-adv: Start new development cycle
====================

Link: https://patch.msgid.link/20251024092315.232636-1-sw@simonwunderlich.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 18:02:38 -07:00
Petr Machata
68800bbf58 net: bridge: Flush multicast groups when snooping is disabled
When forwarding multicast packets, the bridge takes MDB into account when
IGMP / MLD snooping is enabled. Currently, when snooping is disabled, the
MDB is retained, even though it is not used anymore.

At the same time, during the time that snooping is disabled, the IGMP / MLD
control packets are obviously ignored, and after the snooping is reenabled,
the administrator has to assume it is out of sync. In particular, missed
join and leave messages would lead to traffic being forwarded to wrong
interfaces.

Keeping the MDB entries around thus serves no purpose, and just takes
memory. Note also that disabling per-VLAN snooping does actually flush the
relevant MDB entries.

This patch flushes non-permanent MDB entries as global snooping is
disabled.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/5e992df1bb93b88e19c0ea5819e23b669e3dde5d.1761228273.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 17:57:21 -07:00
Wilfred Mallawa
82cb5be6ad net/tls: support setting the maximum payload size
During a handshake, an endpoint may specify a maximum record size limit.
Currently, the kernel defaults to TLS_MAX_PAYLOAD_SIZE (16KB) for the
maximum record size. Meaning that, the outgoing records from the kernel
can exceed a lower size negotiated during the handshake. In such a case,
the TLS endpoint must send a fatal "record_overflow" alert [1], and
thus the record is discarded.

Upcoming Western Digital NVMe-TCP hardware controllers implement TLS
support. For these devices, supporting TLS record size negotiation is
necessary because the maximum TLS record size supported by the controller
is less than the default 16KB currently used by the kernel.

Currently, there is no way to inform the kernel of such a limit. This patch
adds support to a new setsockopt() option `TLS_TX_MAX_PAYLOAD_LEN` that
allows for setting the maximum plaintext fragment size. Once set, outgoing
records are no larger than the size specified. This option can be used to
specify the record size limit.

[1] https://www.rfc-editor.org/rfc/rfc8449

Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20251022001937.20155-1-wilfred.opensource@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27 16:13:42 -07:00
Dust Li
f0773d0b41 smc: rename smc_find_ism_store_rc to reflect broader usage
The function smc_find_ism_store_rc() is used to record the reason
why a suitable device (either ISM or RDMA) could not be found.
However, its name suggests it is ISM-specific, which is misleading.

Rename it to better reflect its actual usage.

No functional changes.

Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251023020012.69609-1-dust.li@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 18:48:03 -07:00
Julia Lawall
d0d2203b9a strparser: fix typo in comment
The name frags_list doesn't appear in the kernel.
It should be frag_list as in the next sentence.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://patch.msgid.link/20251023013051.1728388-1-Julia.Lawall@inria.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 18:47:08 -07:00
Kuniyuki Iwashima
3064d0fe02 neighbour: Convert rwlock of struct neigh_table to spinlock.
Only neigh_for_each() and neigh_seq_start/stop() are on the
reader side of neigh_table.lock.

Let's convert rwlock to the plain spinlock.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251022054004.2514876-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 17:57:20 -07:00
Kuniyuki Iwashima
55a6046b48 neighbour: Convert RTM_SETNEIGHTBL to RCU.
neightbl_set() fetches neigh_tables[] and updates attributes under
write_lock_bh(&tbl->lock), so RTNL is not needed.

neigh_table_clear() synchronises RCU only, and rcu_dereference_rtnl()
protects nothing here.

If we released RCU after fetching neigh_tables[], there would be no
synchronisation to block neigh_table_clear() further, so RCU is held
until the end of the function.

Another option would be to protect neigh_tables[] user with SRCU
and add synchronize_srcu() in neigh_table_clear().

But, holding RCU should be fine as we hold write_lock_bh() for the
rest of neightbl_set() anyway.

Let's perform RTM_SETNEIGHTBL under RCU and drop RTNL.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251022054004.2514876-5-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 17:57:20 -07:00
Kuniyuki Iwashima
4ae34be500 neighbour: Convert RTM_GETNEIGHTBL to RCU.
neightbl_dump_info() calls these functions for each neigh_tables[]
entry:

  1. neightbl_fill_info() for tbl->parms
  2. neightbl_fill_param_info() for tbl->parms_list (except tbl->parms)

Both functions rely on the table lock (read_lock_bh(&tbl->lock))
and RTNL is not needed.

Let's fetch the table under RCU and convert RTM_GETNEIGHTBL to RCU.

Note that the first entry of tbl->parms_list is tbl->parms.list and
embedded in neigh_table, so list_next_entry() is safe.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251022054004.2514876-4-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 17:57:20 -07:00
Kuniyuki Iwashima
35d7c70870 neighbour: Annotate access to neigh_parms fields.
NEIGH_VAR() is read locklessly in the fast path, and IPv6 ndisc uses
NEIGH_VAR_SET() locklessly.

The next patch will convert neightbl_dump_info() to RCU.

Let's annotate accesses to neigh_param with READ_ONCE() and WRITE_ONCE().

Note that ndisc_ifinfo_sysctl_change() uses &NEIGH_VAR() and we cannot
use '&' with READ_ONCE(), so NEIGH_VAR_PTR() is introduced.

Note also that NEIGH_VAR_INIT() does not need WRITE_ONCE() as it is before
parms is published.  Also, the only user hippi_neigh_setup_dev() is no
longer called since commit e3804cbebb ("net: remove COMPAT_NET_DEV_OPS"),
which looks wrong, but probably no one uses HIPPI and RoadRunner.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251022054004.2514876-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 17:57:20 -07:00
Kuniyuki Iwashima
06d6322280 neighbour: Use RCU list helpers for neigh_parms.list writers.
We will convert RTM_GETNEIGHTBL to RCU soon, where we traverse
tbl->parms_list under RCU in neightbl_dump_info().

Let's use RCU list helper for neigh_parms in neigh_parms_alloc()
and neigh_parms_release().

neigh_table_init() uses the plain list_add() for the default
neigh_parm that is embedded in the table and not yet published.

Note that neigh_parms_release() already uses call_rcu() to free
neigh_parms.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251022054004.2514876-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24 17:57:20 -07:00
Eric Biggers
05774d7e42 tcp: Remove unnecessary null check in tcp_inbound_md5_hash()
The 'if (!key && hash_location)' check in tcp_inbound_md5_hash() implies
that hash_location might be null.  However, later code in the function
dereferences hash_location anyway, without checking for null first.
Fortunately, there is no real bug, since tcp_inbound_md5_hash() is
called only with non-null values of hash_location.

Therefore, remove the unnecessary and misleading null check of
hash_location.  This silences a Smatch static checker warning
(https://lore.kernel.org/netdev/aPi4b6aWBbBR52P1@stanley.mountain/)

Also fix the related comment at the beginning of the function.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20251022221209.19716-1-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-23 18:49:55 -07:00
Sunday Adelodun
ec538867a3 net: unix: remove outdated BSD behavior comment in unix_release_sock()
Remove the long-standing comment in unix_release_sock() that described a
behavioral difference between Linux and BSD regarding when ECONNRESET is
sent to connected UNIX sockets upon closure.

As confirmed by testing on macOS (similar to BSD behavior), ECONNRESET
is only observed for SOCK_DGRAM sockets, not for SOCK_STREAM. Meanwhile,
Linux already returns ECONNRESET in cases where a socket is closed with
unread data or is not yet accept()ed. This means the previous comment no
longer accurately describes current behavior and is misleading.

Suggested-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Sunday Adelodun <adelodunolaoluwa@yahoo.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251021195906.20389-1-adelodunolaoluwa@yahoo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-23 17:26:16 -07:00
Jakub Kicinski
2b7553db91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.18-rc3).

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-23 10:53:08 -07:00
Linus Torvalds
ab431bc397 Merge tag 'net-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from can. Slim pickings, I'm guessing people haven't
  really started testing.

  Current release - new code bugs:

   - eth: mlx5e:
       - psp: avoid 'accel' NULL pointer dereference
       - skip PPHCR register query for FEC histogram if not supported

  Previous releases - regressions:

   - bonding: update the slave array for broadcast mode

   - rtnetlink: re-allow deleting FDB entries in user namespace

   - eth: dpaa2: fix the pointer passed to PTR_ALIGN on Tx path

  Previous releases - always broken:

   - can: drop skb on xmit if device is in listen-only mode

   - gro: clear skb_shinfo(skb)->hwtstamps in napi_reuse_skb()

   - eth: mlx5e
       - RX, fix generating skb from non-linear xdp_buff if program
         trims frags
       - make devcom init failures non-fatal, fix races with IPSec

  Misc:

   - some documentation formatting 'fixes'"

* tag 'net-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (47 commits)
  net/mlx5: Fix IPsec cleanup over MPV device
  net/mlx5: Refactor devcom to return NULL on failure
  net/mlx5e: Skip PPHCR register query if not supported by the device
  net/mlx5: Add PPHCR to PCAM supported registers mask
  virtio-net: zero unused hash fields
  net: phy: micrel: always set shared->phydev for LAN8814
  vsock: fix lock inversion in vsock_assign_transport()
  ovpn: use datagram_poll_queue for socket readiness in TCP
  espintcp: use datagram_poll_queue for socket readiness
  net: datagram: introduce datagram_poll_queue for custom receive queues
  net: bonding: fix possible peer notify event loss or dup issue
  net: hsr: prevent creation of HSR device with slaves from another netns
  sctp: avoid NULL dereference when chunk data buffer is missing
  ptp: ocp: Fix typo using index 1 instead of i in SMA initialization loop
  net: ravb: Ensure memory write completes before ringing TX doorbell
  net: ravb: Enforce descriptor type ordering
  net: hibmcge: select FIXED_PHY
  net: dlink: use dev_kfree_skb_any instead of dev_kfree_skb
  Documentation: networking: ax25: update the mailing list info.
  net: gro_cells: fix lock imbalance in gro_cells_receive()
  ...
2025-10-23 07:03:18 -10:00
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
Ralf Lici
0fc3e32c2c espintcp: use datagram_poll_queue for socket readiness
espintcp uses a custom queue (ike_queue) to deliver packets to
userspace. The polling logic relies on datagram_poll, which checks
sk_receive_queue, which can lead to false readiness signals when that
queue contains non-userspace packets.

Switch espintcp_poll to use datagram_poll_queue with ike_queue, ensuring
poll only signals readiness when userspace data is actually available.

Fixes: e27cca96cd ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Ralf Lici <ralf@mandelbit.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20251021100942.195010-3-ralf@mandelbit.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-23 15:46:04 +02:00
Ralf Lici
f6ceec6434 net: datagram: introduce datagram_poll_queue for custom receive queues
Some protocols using TCP encapsulation (e.g., espintcp, openvpn) deliver
userspace-bound packets through a custom skb queue rather than the
standard sk_receive_queue.

Introduce datagram_poll_queue that accepts an explicit receive queue,
and convert datagram_poll into a wrapper around datagram_poll_queue.
This allows protocols with custom skb queues to reuse the core polling
logic without relying on sk_receive_queue.

Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Antonio Quartulli <antonio@openvpn.net>
Signed-off-by: Ralf Lici <ralf@mandelbit.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Antonio Quartulli <antonio@openvpn.net>
Link: https://patch.msgid.link/20251021100942.195010-2-ralf@mandelbit.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-23 15:46:04 +02:00
Fernando Fernandez Mancera
c0178eec88 net: hsr: prevent creation of HSR device with slaves from another netns
HSR/PRP driver does not handle correctly having slaves/interlink devices
in a different net namespace. Currently, it is possible to create a HSR
link in a different net namespace than the slaves/interlink with the
following command:

 ip link add hsr0 netns hsr-ns type hsr slave1 eth1 slave2 eth2

As there is no use-case on supporting this scenario, enforce that HSR
device link matches netns defined by IFLA_LINK_NETNSID.

The iproute2 command mentioned above will throw the following error:

 Error: hsr: HSR slaves/interlink must be on the same net namespace than HSR link.

Fixes: f421436a59 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20251020135533.9373-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-22 19:22:22 -07:00
Alexey Simakov
441f0647f7 sctp: avoid NULL dereference when chunk data buffer is missing
chunk->skb pointer is dereferenced in the if-block where it's supposed
to be NULL only.

chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list
instead and do it just before replacing chunk->skb. We're sure that
otherwise chunk->skb is non-NULL because of outer if() condition.

Fixes: 90017accff ("sctp: Add GSO support")
Signed-off-by: Alexey Simakov <bigalex934@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://patch.msgid.link/20251021130034.6333-1-bigalex934@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-22 19:19:31 -07:00
David Yang
ca4709843b net: dsa: tag_yt921x: add support for Motorcomm YT921x tags
Add support for Motorcomm YT921x tags, which includes a proper
configurable ethertype field (default to 0x9988).

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251017060859.326450-3-mmyangfl@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 18:25:30 -07:00
Hangbin Liu
0152747a52 net: bridge: use common function to compute the features
Previously, bridge ignored all features propagation and DST retention,
only handling explicitly the GSO limits.

By switching to the new helper netdev_compute_master_upper_features(), the bridge
now expose additional features, depending on the lowers capabilities.

Since br_set_gso_limits() is already covered by the helper, it can be
removed safely.

Bridge has it's own way to update needed_headroom. So we don't need to
update it in the helper.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20251017034155.61990-5-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 18:08:23 -07:00
Hangbin Liu
28098defc7 net: add a common function to compute features for upper devices
Some high level software drivers need to compute features from lower
devices. But each has their own implementations and may lost some
feature compute. Let's use one common function to compute features
for kinds of these devices.

The new helper uses the current bond implementation as the reference
one, as the latter already handles all the relevant aspects: netdev
features, TSO limits and dst retention.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20251017034155.61990-2-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 18:08:23 -07:00
Eric Dumazet
c5394b8b7a net: gro_cells: fix lock imbalance in gro_cells_receive()
syzbot found that the local_unlock_nested_bh() call was
missing in some cases.

WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.2.329/7421 is trying to acquire lock:
 ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: gro_cells_receive+0x404/0x790 net/core/gro_cells.c:30

but task is already holding lock:
 ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: gro_cells_receive+0x404/0x790 net/core/gro_cells.c:30

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock((&cell->bh_lock));
  lock((&cell->bh_lock));

 *** DEADLOCK ***

Given the introduction of @have_bh_lock variable, it seems the author
intent was to have the local_unlock_nested_bh() after the @unlock label.

Fixes: 25718fdcbd ("net: gro_cells: Use nested-BH locking for gro_cell")
Reported-by: syzbot+f9651b9a8212e1c8906f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68f65eb9.a70a0220.205af.0034.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20251020161114.1891141-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:41:09 -07:00
Alok Tiwari
0364ca3309 devlink: region: correct port region lookup to use port_ops
The function devlink_port_region_get_by_name() incorrectly uses
region->ops->name to compare the region name. as it is not any critical
impact as ops and port_ops define as union for devlink_region but as per
code logic it should refer port_ops here.

No functional impact as ops and port_ops are part of same union,
and name is the first member of both.

Update it to use region->port_ops->name to properly reference
the name of the devlink port region.

Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20251020170916.1741808-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:40:26 -07:00
Matthieu Baerts (NGI0)
e84cb860ac mptcp: pm: in-kernel: C-flag: handle late ADD_ADDR
The special C-flag case expects the ADD_ADDR to be received when
switching to 'fully-established'. But for various reasons, the ADD_ADDR
could be sent after the "4th ACK", and the special case doesn't work.

On NIPA, the new test validating this special case for the C-flag failed
a few times, e.g.

  102 default limits, server deny join id 0
        syn rx                 [FAIL] got 0 JOIN[s] syn rx expected 2

  Server ns stats
  (...)
  MPTcpExtAddAddrTx  1
  MPTcpExtEchoAdd    1

  Client ns stats
  (...)
  MPTcpExtAddAddr    1
  MPTcpExtEchoAddTx  1

        synack rx              [FAIL] got 0 JOIN[s] synack rx expected 2
        ack rx                 [FAIL] got 0 JOIN[s] ack rx expected 2
        join Rx                [FAIL] see above
        syn tx                 [FAIL] got 0 JOIN[s] syn tx expected 2
        join Tx                [FAIL] see above

I had a suspicion about what the issue could be: the ADD_ADDR might have
been received after the switch to the 'fully-established' state. The
issue was not easy to reproduce. The packet capture shown that the
ADD_ADDR can indeed be sent with a delay, and the client would not try
to establish subflows to it as expected.

A simple fix is not to mark the endpoints as 'used' in the C-flag case,
when looking at creating subflows to the remote initial IP address and
port. In this case, there is no need to try.

Note: newly added fullmesh endpoints will still continue to be used as
expected, thanks to the conditions behind mptcp_pm_add_addr_c_flag_case.

Fixes: 4b1ff850e0 ("mptcp: pm: in-kernel: usable client side with C-flag")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-1-8207030cb0e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:36:45 -07:00
Eric Dumazet
3ff9bcecce net: avoid extra access to sk->sk_wmem_alloc in sock_wfree()
UDP TX packets destructor is sock_wfree().

It suffers from a cache line bouncing in sock_def_write_space_wfree().

Instead of reading sk->sk_wmem_alloc after we just did an atomic RMW
on it, use __refcount_sub_and_test() to get the old value for free,
and pass the new value to sock_def_write_space_wfree().

Add __sock_writeable() helper.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251017133712.2842665-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-21 15:56:21 +02:00
Aswin Karuvally
38516e3fa4 s390/iucv: Convert sprintf/snprintf to scnprintf
Convert sprintf/snprintf calls to scnprintf to better align with the
kernel development community practices [1].

Link: https://lwn.net/Articles/69419 [1]
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Aswin Karuvally <aswin@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251017094954.1402684-1-wintera@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-20 18:35:21 -07:00
Wang Liang
f584239a9e net/smc: fix general protection fault in __smc_diag_dump
The syzbot report a crash:

  Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
  KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
  CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
  RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
  Call Trace:
   <TASK>
   smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
   smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
   netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
   __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
   netlink_dump_start include/linux/netlink.h:341 [inline]
   smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
   __sock_diag_cmd net/core/sock_diag.c:249 [inline]
   sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
   netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
   netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
   netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
   netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
   sock_sendmsg_nosec net/socket.c:714 [inline]
   __sock_sendmsg net/socket.c:729 [inline]
   ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
   ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
   __sys_sendmsg+0x16d/0x220 net/socket.c:2700
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>

The process like this:

               (CPU1)              |             (CPU2)
  ---------------------------------|-------------------------------
  inet_create()                    |
    // init clcsock to NULL        |
    sk = sk_alloc()                |
                                   |
    // unexpectedly change clcsock |
    inet_init_csk_locks()          |
                                   |
    // add sk to hash table        |
    smc_inet_init_sock()           |
      smc_sk_init()                |
        smc_hash_sk()              |
                                   | // traverse the hash table
                                   | smc_diag_dump_proto
                                   |   __smc_diag_dump()
                                   |     // visit wrong clcsock
                                   |     smc_diag_msg_common_fill()
    // alloc clcsock               |
    smc_create_clcsk               |
      sock_create_kern             |

With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
just remove it.

After removing the INET_PROTOSW_ICSK flag, this patch alse revert
commit 6fd27ea183 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
to avoid casting smc_sock to inet_connection_sock.

Reported-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
Tested-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
Fixes: d25a92ccae ("net/smc: Introduce IPPROTO_SMC")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Link: https://patch.msgid.link/20251017024827.3137512-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-20 17:46:06 -07:00
Eric Dumazet
a5cd3a60aa net: shrink napi_skb_cache_{put,get}() and napi_skb_cache_get_bulk()
Following loop in napi_skb_cache_put() is unrolled by the compiler
even if CONFIG_KASAN is not enabled:

for (i = NAPI_SKB_CACHE_HALF; i < NAPI_SKB_CACHE_SIZE; i++)
	kasan_mempool_unpoison_object(nc->skb_cache[i],
				kmem_cache_size(net_hotdata.skbuff_cache));

We have 32 times this sequence, for a total of 384 bytes.

	48 8b 3d 00 00 00 00 	net_hotdata.skbuff_cache,%rdi
	e8 00 00 00 00       	call   kmem_cache_size

This is because kmem_cache_size() is not an inline and not const,
and kasan_unpoison_object_data() is an inline function.

Cache kmem_cache_size() result in a variable, so that
the compiler can remove dead code (and variable) when/if
CONFIG_KASAN is unset.

After this patch, napi_skb_cache_put() is inlined in its callers,
and we avoid one kmem_cache_size() call in napi_skb_cache_get()
and napi_skb_cache_get_bulk().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20251016182911.1132792-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-20 17:37:57 -07:00
Eric Dumazet
f8a55d5e71 net: add a fast path in __netif_schedule()
Cpus serving NIC interrupts and specifically TX completions are often
trapped in also restarting a busy qdisc (because qdisc was stopped by BQL
or the driver's own flow control).

When they call netdev_tx_completed_queue() or netif_tx_wake_queue(),
they call __netif_schedule() so that the queue can be run
later from net_tx_action() (involving NET_TX_SOFTIRQ)

Quite often, by the time the cpu reaches net_tx_action(), another cpu
grabbed the qdisc spinlock from __dev_xmit_skb(), and we spend too much
time spinning on this lock.

We can detect in __netif_schedule() if a cpu is already at a specific
point in __dev_xmit_skb() where we have the guarantee the queue will
be run.

This patch gives a 13 % increase of throughput on an IDPF NIC (200Gbit),
32 TX qeues, sending UDP packets of 120 bytes.

This also helps __qdisc_run() to not force a NET_TX_SOFTIRQ
if another thread is waiting in __dev_xmit_skb()

Before:

sar -n DEV 5 5|grep eth1|grep Average
Average:         eth1   1496.44 52191462.56    210.00 13369396.90      0.00      0.00      0.00     54.76

After:

sar -n DEV 5 5|grep eth1|grep Average
Average:         eth1   1457.88 59363099.96    205.08 15206384.35      0.00      0.00      0.00     62.29

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251017145334.3016097-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-20 16:45:25 -07:00
Linus Torvalds
d303caf5ca Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Alexei Starovoitov:

 - Replace bpf_map_kmalloc_node() with kmalloc_nolock() to fix kmemleak
   imbalance in tracking of bpf_async_cb structures (Alexei Starovoitov)

 - Make selftests/bpf arg_parsing.c more robust to errors (Andrii
   Nakryiko)

 - Fix redefinition of 'off' as different kind of symbol when I40E
   driver is builtin (Brahmajit Das)

 - Do not disable preemption in bpf_test_run (Sahil Chandna)

 - Fix memory leak in __lookup_instance error path (Shardul Bankar)

 - Ensure test data is flushed to disk before reading it (Xing Guo)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Fix redefinition of 'off' as different kind of symbol
  bpf: Do not disable preemption in bpf_test_run().
  bpf: Fix memory leak in __lookup_instance error path
  selftests: arg_parsing: Ensure data is flushed to disk before reading.
  bpf: Replace bpf_map_kmalloc_node() with kmalloc_nolock() to allocate bpf_async_cb structures.
  selftests/bpf: make arg_parsing.c more robust to crashes
  bpf: test_run: Fix ctx leak in bpf_prog_test_run_xdp error path
2025-10-18 08:00:43 -10:00
Jakub Kicinski
e90576829c Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-10-16

We've added 6 non-merge commits during the last 1 day(s) which contain
a total of 18 files changed, 577 insertions(+), 38 deletions(-).

The main changes are:

1) Bypass the global per-protocol memory accounting either by setting
   a netns sysctl or using bpf_setsockopt in a bpf program,
   from Kuniyuki Iwashima.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Add test for sk->sk_bypass_prot_mem.
  bpf: Introduce SK_BPF_BYPASS_PROT_MEM.
  bpf: Support bpf_setsockopt() for BPF_CGROUP_INET_SOCK_CREATE.
  net: Introduce net.core.bypass_prot_mem sysctl.
  net: Allow opt-out from global protocol memory accounting.
  tcp: Save lock_sock() for memcg in inet_csk_accept().
====================

Link: https://patch.msgid.link/20251016204539.773707-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17 17:20:42 -07:00
Eric Biggers
37a183d3b7 tcp: Convert tcp-md5 to use MD5 library instead of crypto_ahash
Make tcp-md5 use the MD5 library API (added in 6.18) instead of the
crypto_ahash API.  This is much simpler and also more efficient:

- The library API just operates on struct md5_ctx.  Just allocate this
  struct on the stack instead of using a pool of pre-allocated
  crypto_ahash and ahash_request objects.

- The library API accepts standard pointers and doesn't require
  scatterlists.  So, for hashing the headers just use an on-stack buffer
  instead of a pool of pre-allocated kmalloc'ed scratch buffers.

- The library API never fails.  Therefore, checking for MD5 hashing
  errors is no longer necessary.  Update tcp_v4_md5_hash_skb(),
  tcp_v6_md5_hash_skb(), tcp_v4_md5_hash_hdr(), tcp_v6_md5_hash_hdr(),
  tcp_md5_hash_key(), tcp_sock_af_ops::calc_md5_hash, and
  tcp_request_sock_ops::calc_md5_hash to return void instead of int.

- The library API provides direct access to the MD5 code, eliminating
  unnecessary overhead such as indirect function calls and scatterlist
  management.  Microbenchmarks of tcp_v4_md5_hash_skb() on x86_64 show a
  speedup from 7518 to 7041 cycles (6% fewer) with skb->len == 1440, or
  from 1020 to 678 cycles (33% fewer) with skb->len == 140.

Since tcp_sigpool_hash_skb_data() can no longer be used, add a function
tcp_md5_hash_skb_data() which is specialized to MD5.  Of course, to the
extent that this duplicates any code, it's well worth it.

To preserve the existing behavior of TCP-MD5 support being disabled when
the kernel is booted with "fips=1", make tcp_md5_do_add() check
fips_enabled itself.  Previously it relied on the error from
crypto_alloc_ahash("md5") being bubbled up.  I don't know for sure that
this is actually needed, but this preserves the existing behavior.

Tested with bidirectional TCP-MD5, both IPv4 and IPv6, between a kernel
that includes this commit and a kernel that doesn't include this commit.

(Side note: please don't use TCP-MD5!  It's cryptographically weak.  But
as long as Linux supports it, it might as well be implemented properly.)

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20251014215836.115616-1-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17 17:14:54 -07:00
Florian Westphal
2af8ff1e47 net: Kconfig: discourage drop_monitor enablement
Quoting Eric Dumazet:
"I do not understand the fascination with net/core/drop_monitor.c [..]
misses all the features, flexibility, scalability  that 'perf',
eBPF tracing, bpftrace, .... have today."

Reword DROP_MONITOR kconfig help text to clearly state that its not
related to perf-based drop monitoring and that its safe to disable
this unless support for the older netlink-based tools is needed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251016115147.18503-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17 16:29:26 -07:00