linux.git/drivers/net/netdevsim/dev.c, branch v6.12.80

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

2026-01-30T09:28:42+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

netdevsim: use cond_resched() in nsim_dev_trap_report_work()

2024-10-15T16:58:43+00:00

I am still seeing many syzbot reports hinting that syzbot
might fool nsim_dev_trap_report_work() with hundreds of ports [1]

Lets use cond_resched(), and system_unbound_wq
instead of implicit system_wq.

[1]
INFO: task syz-executor:20633 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25856 pid:20633 tgid:20633 ppid:1      flags:0x00004006
...
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16760 Comm: kworker/1:0 Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events nsim_dev_trap_report_work
 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d 04 fb 9c 0c 48 89 de 5b e9 c3 c7 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90  0f 1e fa 48 8b 04 24 65 48 8b 0c 25 c0 d7 03 00 65 8b 15 60 f0
RSP: 0018:ffffc90000a187e8 EFLAGS: 00000246
RAX: 0000000000000100 RBX: ffffc90000a188e0 RCX: ffff888027d3bc00
RDX: ffff888027d3bc00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88804a2e6000 R08: ffffffff8a4bc495 R09: ffffffff89da3577
R10: 0000000000000004 R11: ffffffff8a4bc2b0 R12: dffffc0000000000
R13: ffff88806573b503 R14: dffffc0000000000 R15: ffff8880663cca00
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc90a747f98 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 000000000000002b DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 
 
 
  __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
  spin_unlock_bh include/linux/spinlock.h:396 [inline]
  nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
  nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850
  process_one_work kernel/workqueue.c:3229 [inline]
  process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
  worker_thread+0x870/0xd30 kernel/workqueue.c:3391
  kthread+0x2f0/0x390 kernel/kthread.c:389
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 

Fixes: ba5e1272142d ("netdevsim: avoid potential loop in nsim_dev_trap_report_work()")
Reported-by: syzbot+d383dc9579a76f56c251@syzkaller.appspotmail.com
Reported-by: syzbot+c596faae21a68bf7afd0@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet 
Cc: Jiri Pirko 
Link: https://patch.msgid.link/20241012094230.3893510-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

netdevsim: avoid potential loop in nsim_dev_trap_report_work()

2024-02-02T19:00:38+00:00

Many syzbot reports include the following trace [1]

If nsim_dev_trap_report_work() can not grab the mutex,
it should rearm itself at least one jiffie later.

[1]
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 32383 Comm: kworker/0:2 Not tainted 6.8.0-rc2-syzkaller-00031-g861c0981648f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: events nsim_dev_trap_report_work
 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:89 [inline]
 RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
 RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
 RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
 RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
 RIP: 0010:kasan_check_range+0x101/0x190 mm/kasan/generic.c:189
Code: 07 49 39 d1 75 0a 45 3a 11 b8 01 00 00 00 7c 0b 44 89 c2 e8 21 ed ff ff 83 f0 01 5b 5d 41 5c c3 48 85 d2 74 4f 48 01 ea eb 09 <48> 83 c0 01 48 39 d0 74 41 80 38 00 74 f2 eb b6 41 bc 08 00 00 00
RSP: 0018:ffffc90012dcf998 EFLAGS: 00000046
RAX: fffffbfff258af1e RBX: fffffbfff258af1f RCX: ffffffff8168eda3
RDX: fffffbfff258af1f RSI: 0000000000000004 RDI: ffffffff92c578f0
RBP: fffffbfff258af1e R08: 0000000000000000 R09: fffffbfff258af1e
R10: ffffffff92c578f3 R11: ffffffff8acbcbc0 R12: 0000000000000002
R13: ffff88806db38400 R14: 1ffff920025b9f42 R15: ffffffff92c578e8
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00994e078 CR3: 000000002c250000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 
 
  instrument_atomic_read include/linux/instrumented.h:68 [inline]
  atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
  queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline]
  debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline]
  do_raw_spin_unlock+0x53/0x230 kernel/locking/spinlock_debug.c:141
  __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
  _raw_spin_unlock_irqrestore+0x22/0x70 kernel/locking/spinlock.c:194
  debug_object_activate+0x349/0x540 lib/debugobjects.c:726
  debug_work_activate kernel/workqueue.c:578 [inline]
  insert_work+0x30/0x230 kernel/workqueue.c:1650
  __queue_work+0x62e/0x11d0 kernel/workqueue.c:1802
  __queue_delayed_work+0x1bf/0x270 kernel/workqueue.c:1953
  queue_delayed_work_on+0x106/0x130 kernel/workqueue.c:1989
  queue_delayed_work include/linux/workqueue.h:563 [inline]
  schedule_delayed_work include/linux/workqueue.h:677 [inline]
  nsim_dev_trap_report_work+0x9c0/0xc80 drivers/net/netdevsim/dev.c:842
  process_one_work+0x886/0x15d0 kernel/workqueue.c:2633
  process_scheduled_works kernel/workqueue.c:2706 [inline]
  worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787
  kthread+0x2c6/0x3a0 kernel/kthread.c:388
  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 

Fixes: 012ec02ae441 ("netdevsim: convert driver to use unlocked devlink API during init/fini")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Jiri Pirko 
Link: https://lore.kernel.org/r/20240201175324.3752746-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

netdevsim: fix uninitialized data in nsim_dev_trap_fa_cookie_write()

2023-07-12T19:46:35+00:00

The simple_write_to_buffer() function is designed to handle partial
writes.  It returns negatives on error, otherwise it returns the number
of bytes that were able to be copied.  This code doesn't check the
return properly.  We only know that the first byte is written, the rest
of the buffer might be uninitialized.

There is no need to use the simple_write_to_buffer() function.
Partial writes are prohibited by the "if (*ppos != 0)" check at the
start of the function.  Just use memdup_user() and copy the whole
buffer.

Fixes: d3cbb907ae57 ("netdevsim: add ACL trap reporting cookie as a metadata")
Signed-off-by: Dan Carpenter 
Reviewed-by: Pavan Chebbi 
Reviewed-by: Ido Schimmel 
Link: https://lore.kernel.org/r/7c1f950b-3a7d-4252-82a6-876e53078ef7@moroto.mountain
Signed-off-by: Jakub Kicinski

devlink: remove devlink features

2023-01-30T08:37:46+00:00

Devlink features were introduced to disallow devlink reload calls of
userspace before the devlink was fully initialized. The reason for this
workaround was the fact that devlink reload was originally called
without devlink instance lock held.

However, with recent changes that converted devlink reload to be
performed under devlink instance lock, this is redundant so remove
devlink features entirely.

Note that mlx5 used this to enable devlink reload conditionally only
when device didn't act as multi port slave. Move the multi port check
into mlx5_devlink_reload_down() callback alongside with the other
checks preventing the device from reload in certain states.

Signed-off-by: Jiri Pirko 
Reviewed-by: Jacob Keller 
Signed-off-by: David S. Miller

devlink: protect devlink param list by instance lock

2023-01-27T12:32:02+00:00

Commit 1d18bb1a4ddd ("devlink: allow registering parameters after
the instance") as the subject implies introduced possibility to register
devlink params even for already registered devlink instance. This is a
bit problematic, as the consistency or params list was originally
secured by the fact it is static during devlink lifetime. So in order to
protect the params list, take devlink instance lock during the params
operations. Introduce unlocked function variants and use them in drivers
in locked context. Put lock assertions to appropriate places.

Signed-off-by: Jiri Pirko 
Reviewed-by: Jakub Kicinski 
Reviewed-by: Jacob Keller 
Reviewed-by: Ido Schimmel 
Reviewed-by: Simon Horman 
Tested-by: Simon Horman 
Signed-off-by: David S. Miller

netdevsim: move devlink registration under the instance lock

2023-01-06T12:56:19+00:00

To prevent races with netdev code accessing free devlink instances
move the registration under the devlink instance lock.
Core now waits for the instance to be registered before accessing it.

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

netdevsim: rename a label

2023-01-06T12:56:19+00:00

err_dl_unregister should unregister the devlink instance.
Looks like renaming it was missed in one of the reshufflings.

Reviewed-by: Jacob Keller 
Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net: devlink: let the core report the driver name instead of the drivers

2022-12-01T05:49:38+00:00

The driver name is available in device_driver::name. Right now,
drivers still have to report this piece of information themselves in
their devlink_ops::info_get callback function.

In order to factorize code, make devlink_nl_info_fill() add the driver
name attribute.

Now that the core sets the driver name attribute, drivers are not
supposed to call devlink_info_driver_name_put() anymore. Remove
devlink_info_driver_name_put() and clean-up all the drivers using this
function in their callback.

Signed-off-by: Vincent Mailhol 
Tested-by: Ido Schimmel  # mlxsw
Reviewed-by: Jacob Keller  
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski

devlink: Allow to set up parent in devl_rate_leaf_create()

2022-11-18T05:41:27+00:00

Currently the driver is able to create leaf nodes for the devlink-rate,
but is unable to set parent for them. This wasn't as issue before the
possibility to export hierarchy from the driver. After adding the export
feature, in order for the driver to supply correct hierarchy, it's
necessary for it to be able to supply a parent name to
devl_rate_leaf_create().

Introduce a new parameter 'parent_name' in devl_rate_leaf_create().

Signed-off-by: Michal Wilczynski 
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski