linux.git/drivers/net/netdevsim, branch v6.18.21

netdevsim: drop PSP ext ref on forward failure

2026-03-25T10:10:42+00:00

[ Upstream commit 7d9351435ebba08bbb60f42793175c9dc714d2fb ]

nsim_do_psp() takes an extra reference to the PSP skb extension so the
extension survives __dev_forward_skb(). That forward path scrubs the skb
and drops attached skb extensions before nsim_psp_handle_ext() can
reattach the PSP metadata.

If __dev_forward_skb() fails in nsim_forward_skb(), the function returns
before nsim_psp_handle_ext() can attach that extension to the skb, leaving
the extra reference leaked.

Drop the saved PSP extension reference before returning from the
forward-failure path. Guard the put because plain or non-decapsulated
traffic can also fail forwarding without ever taking the extra PSP
reference.

Fixes: f857478d6206 ("netdevsim: a basic test PSP implementation")
Signed-off-by: Wesley Atwell 
Reviewed-by: Daniel Zahka 
Link: https://patch.msgid.link/20260317061431.1482716-1-atwellwea@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

netdevsim: fix a race issue related to the operation on bpf_bound_progs list

2026-01-30T09:32:17+00:00

[ Upstream commit b97d5eedf4976cc94321243be83b39efe81a0e15 ]

The netdevsim driver lacks a protection mechanism for operations on the
bpf_bound_progs list. When the nsim_bpf_create_prog() performs
list_add_tail, it is possible that nsim_bpf_destroy_prog() is
simultaneously performs list_del. Concurrent operations on the list may
lead to list corruption and trigger a kernel crash as follows:

[  417.290971] kernel BUG at lib/list_debug.c:62!
[  417.290983] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  417.290992] CPU: 10 PID: 168 Comm: kworker/10:1 Kdump: loaded Not tainted 6.19.0-rc5 #1
[  417.291003] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  417.291007] Workqueue: events bpf_prog_free_deferred
[  417.291021] RIP: 0010:__list_del_entry_valid_or_report+0xa7/0xc0
[  417.291034] Code: a8 ff 0f 0b 48 89 fe 48 89 ca 48 c7 c7 48 a1 eb ae e8 ed fb a8 ff 0f 0b 48 89 fe 48 89 c2 48 c7 c7 80 a1 eb ae e8 d9 fb a8 ff <0f> 0b 48 89 d1 48 c7 c7 d0 a1 eb ae 48 89 f2 48 89 c6 e8 c2 fb a8
[  417.291040] RSP: 0018:ffffb16a40807df8 EFLAGS: 00010246
[  417.291046] RAX: 000000000000006d RBX: ffff8e589866f500 RCX: 0000000000000000
[  417.291051] RDX: 0000000000000000 RSI: ffff8e59f7b23180 RDI: ffff8e59f7b23180
[  417.291055] RBP: ffffb16a412c9000 R08: 0000000000000000 R09: 0000000000000003
[  417.291059] R10: ffffb16a40807c80 R11: ffffffffaf9edce8 R12: ffff8e594427ac20
[  417.291063] R13: ffff8e59f7b44780 R14: ffff8e58800b7a05 R15: 0000000000000000
[  417.291074] FS:  0000000000000000(0000) GS:ffff8e59f7b00000(0000) knlGS:0000000000000000
[  417.291079] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  417.291083] CR2: 00007fc4083efe08 CR3: 00000001c3626006 CR4: 0000000000770ee0
[  417.291088] PKRU: 55555554
[  417.291091] Call Trace:
[  417.291096]  
[  417.291103]  nsim_bpf_destroy_prog+0x31/0x80 [netdevsim]
[  417.291154]  __bpf_prog_offload_destroy+0x2a/0x80
[  417.291163]  bpf_prog_dev_bound_destroy+0x6f/0xb0
[  417.291171]  bpf_prog_free_deferred+0x18e/0x1a0
[  417.291178]  process_one_work+0x18a/0x3a0
[  417.291188]  worker_thread+0x27b/0x3a0
[  417.291197]  ? __pfx_worker_thread+0x10/0x10
[  417.291207]  kthread+0xe5/0x120
[  417.291214]  ? __pfx_kthread+0x10/0x10
[  417.291221]  ret_from_fork+0x31/0x50
[  417.291230]  ? __pfx_kthread+0x10/0x10
[  417.291236]  ret_from_fork_asm+0x1a/0x30
[  417.291246]  

Add a mutex lock, to prevent simultaneous addition and deletion operations
on the list.

Fixes: 31d3ad832948 ("netdevsim: add bpf offload support")
Reported-by: Yinhao Hu 
Reported-by: Kaiyan Mei 
Signed-off-by: Yun Lu 
Link: https://patch.msgid.link/20260116095308.11441-1-luyun_611@163.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: netdevsim: fix inconsistent carrier state after link/unlink

2026-01-17T15:35:28+00:00

[ Upstream commit d83dddffe1904e4a576d11a541878850a8e64cd2 ]

This patch fixes the edge case behavior on ifup/ifdown and
linking/unlinking two netdevsim interfaces:

1. unlink two interfaces netdevsim1 and netdevsim2
2. ifdown netdevsim1
3. ifup netdevsim1
4. link two interfaces netdevsim1 and netdevsim2
5. (Now two interfaces are linked in terms of netdevsim peer, but
    carrier state of the two interfaces remains DOWN.)

This inconsistent behavior is caused by the current implementation,
which only cares about the "link, then ifup" order, not "ifup, then
link" order. This patch fixes the inconsistency by calling
netif_carrier_on() when two netdevsim interfaces are linked.

This patch fixes buggy behavior on NetworkManager-based systems which
causes the netdevsim test to fail with the following error:

  # timeout set to 600
  # selftests: drivers/net/netdevsim: peer.sh
  # 2025/12/25 00:54:03 socat[9115] W address is opened in read-write mode but only supports read-only
  # 2025/12/25 00:56:17 socat[9115] W connect(7, AF=2 192.168.1.1:1234, 16): Connection timed out
  # 2025/12/25 00:56:17 socat[9115] E TCP:192.168.1.1:1234: Connection timed out
  # expected 3 bytes, got 0
  # 2025/12/25 00:56:17 socat[9109] W exiting on signal 15
  not ok 13 selftests: drivers/net/netdevsim: peer.sh # exit=1

This patch also solves timeout on TCP Fast Open (TFO) test in
NetworkManager-based systems because it also depends on netdevsim's
carrier consistency.

Fixes: 1a8fed52f7be ("netdevsim: set the carrier when the device goes up")
Signed-off-by: Yohei Kojima 
Reviewed-by: Breno Leitao 
Link: https://patch.msgid.link/602c9e1ba5bb2ee1997bb38b1d866c9c3b807ae9.1767624906.git.yk@y-koj.net
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

netdevsim: set the carrier when the device goes up

2025-10-16T00:43:17+00:00

Bringing a linked netdevsim device down and then up causes communication
failure because both interfaces lack carrier. Basically a ifdown/ifup on
the interface make the link broken.

Commit 3762ec05a9fbda ("netdevsim: add NAPI support") added supported
for NAPI, calling netif_carrier_off() in nsim_stop(). This patch
re-enables the carrier symmetrically on nsim_open(), in case the device
is linked and the peer is up.

Signed-off-by: Breno Leitao 
Fixes: 3762ec05a9fbda ("netdevsim: add NAPI support")
Reviewed-by: Andrew Lunn 
Link: https://patch.msgid.link/20251014-netdevsim_fix-v2-1-53b40590dae1@debian.org
Signed-off-by: Jakub Kicinski

netdevsim: a basic test PSP implementation

2025-09-30T13:17:21+00:00

Provide a PSP implementation for netdevsim.

Use psp_dev_encapsulate() and psp_dev_rcv() to do actual encapsulation
and decapsulation on skbs, but perform no encryption or decryption. In
order to make encryption with a bad key result in a drop on the peer's
rx side, we stash our psd's generation number in the first byte of each
key before handing to the peer.

Signed-off-by: Jakub Kicinski 
Co-developed-by: Daniel Zahka 
Signed-off-by: Daniel Zahka 
Link: https://patch.msgid.link/20250927225420.1443468-2-kuba@kernel.org
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni

ethtool: add FEC bins histogram report

2025-09-26T23:49:18+00:00

IEEE 802.3ck-2022 defines counters for FEC bins and 802.3df-2024
clarifies it a bit further. Implement reporting interface through as
addition to FEC stats available in ethtool. Drivers can leave bin
counter uninitialized if per-lane values are provided. In this case the
core will recalculate summ for the bin.

Signed-off-by: Vadim Fedorenko 
Reviewed-by: Aleksandr Loktionov 
Link: https://patch.msgid.link/20250924124037.1508846-2-vadim.fedorenko@linux.dev
Signed-off-by: Jakub Kicinski

net: replace use of system_unbound_wq with system_dfl_wq

2025-09-23T00:40:30+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.

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

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

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

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

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Link: https://patch.msgid.link/20250918142427.309519-2-marco.crivellari@suse.com
Signed-off-by: Jakub Kicinski

devlink: Move graceful period parameter to reporter ops

2025-08-27T00:24:16+00:00

Move the default graceful period from a parameter to
devlink_health_reporter_create() to a field in the
devlink_health_reporter_ops structure.

This change improves consistency, as the graceful period is inherently
tied to the reporter's behavior and recovery policy. It simplifies the
signature of devlink_health_reporter_create() and its internal helper
functions. It also centralizes the reporter configuration at the ops
structure, preparing the groundwork for a downstream patch that will
introduce a devlink health reporter burst period attribute whose
default value will similarly be provided by the driver via the ops
structure.

Signed-off-by: Shahar Shitrit 
Reviewed-by: Jiri Pirko 
Signed-off-by: Mark Bloch 
Link: https://patch.msgid.link/20250824084354.533182-2-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski

netdevsim: Fix wild pointer access in nsim_queue_free().

2025-08-14T00:26:39+00:00

syzbot reported the splat below. [0]

When nsim_queue_uninit() is called from nsim_init_netdevsim(),
register_netdevice() has not been called, thus dev->dstats has
not been allocated.

Let's not call dev_dstats_rx_dropped_add() in such a case.

[0]
BUG: unable to handle page fault for address: ffff88809782c020
 PF: supervisor write access in kernel mode
 PF: error_code(0x0002) - not-present page
PGD 1b401067 P4D 1b401067 PUD 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 8476 Comm: syz.1.251 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:local_add arch/x86/include/asm/local.h:33 [inline]
RIP: 0010:u64_stats_add include/linux/u64_stats_sync.h:89 [inline]
RIP: 0010:dev_dstats_rx_dropped_add include/linux/netdevice.h:3027 [inline]
RIP: 0010:nsim_queue_free+0xba/0x120 drivers/net/netdevsim/netdev.c:714
Code: 07 77 6c 4a 8d 3c ed 20 7e f1 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 46 4a 03 1c ed 20 7e f1 8d <4c> 01 63 20 be 00 02 00 00 48 8d 3d 00 00 00 00 e8 61 2f 58 fa 48
RSP: 0018:ffffc900044af150 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: ffff88809782c000 RCX: 00000000000079c3
RDX: 1ffffffff1be2fc7 RSI: ffffffff8c15f380 RDI: ffffffff8df17e38
RBP: ffff88805f59d000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000003 R14: ffff88806ceb3d00 R15: ffffed100dfd308e
FS:  0000000000000000(0000) GS:ffff88809782c000(0063) knlGS:00000000f505db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffff88809782c020 CR3: 000000006fc6a000 CR4: 0000000000352ef0
Call Trace:
 
 nsim_queue_uninit drivers/net/netdevsim/netdev.c:993 [inline]
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1049 [inline]
 nsim_create+0xd0a/0x1260 drivers/net/netdevsim/netdev.c:1101
 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x322/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/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_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f505d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 
Modules linked in:
CR2: ffff88809782c020

Fixes: 2a68a22304f9 ("netdevsim: account dropped packet length in stats on queue free")
Reported-by: syzbot+8aa80c6232008f7b957d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/688bb9ca.a00a0220.26d0e1.0050.GAE@google.com/
Suggested-by: Jakub Kicinski 
Signed-off-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250812162130.4129322-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski

netdevsim: access ->pp through netmem_desc instead of page

2025-07-24T00:46:54+00:00

To eliminate the use of struct page in page pool, the page pool users
should use netmem descriptor and APIs instead.

Make netdevsim access ->pp through netmem_desc instead of page.

Signed-off-by: Byungchul Park 
Link: https://patch.msgid.link/20250721021835.63939-5-byungchul@sk.com
Signed-off-by: Jakub Kicinski