linux-stable.git/net/core/dev.c, branch linux-6.15.y Linux kernel stable tree hv_netvsc: fix potential deadlock in netvsc_vf_setxdp() 2025-06-27T10:13:09+00:00 Saurabh Sengar ssengar@linux.microsoft.com 2025-05-29T10:18:30+00:00 288f9bfc91c69ced4dcf4c5a2582a12c54e1d522 commit 3ec523304976648b45a3eef045e97d17122ff1b2 upstream. The MANA driver's probe registers netdevice via the following call chain: mana_probe() register_netdev() register_netdevice() register_netdevice() calls notifier callback for netvsc driver, holding the netdev mutex via netdev_lock_ops(). Further this netvsc notifier callback end up attempting to acquire the same lock again in dev_xdp_propagate() leading to deadlock. netvsc_netdev_event() netvsc_vf_setxdp() dev_xdp_propagate() This deadlock was not observed so far because net_shaper_ops was never set, and thus the lock was effectively a no-op in this case. Fix this by using netif_xdp_propagate() instead of dev_xdp_propagate() to avoid recursive locking in this path. And, since no deadlock is observed on the other path which is via netvsc_probe, add the lock exclusivly for that path. Also, clean up the unregistration path by removing the unnecessary call to netvsc_vf_setxdp(), since unregister_netdevice_many_notify() already performs this cleanup via dev_xdp_uninstall(). Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf") Cc: stable@vger.kernel.org Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Tested-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com> Link: https://patch.msgid.link/1748513910-23963-1-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3ec523304976648b45a3eef045e97d17122ff1b2 upstream.

The MANA driver's probe registers netdevice via the following call chain:

mana_probe()
  register_netdev()
    register_netdevice()

register_netdevice() calls notifier callback for netvsc driver,
holding the netdev mutex via netdev_lock_ops().

Further this netvsc notifier callback end up attempting to acquire the
same lock again in dev_xdp_propagate() leading to deadlock.

netvsc_netdev_event()
  netvsc_vf_setxdp()
    dev_xdp_propagate()

This deadlock was not observed so far because net_shaper_ops was never set,
and thus the lock was effectively a no-op in this case. Fix this by using
netif_xdp_propagate() instead of dev_xdp_propagate() to avoid recursive
locking in this path.

And, since no deadlock is observed on the other path which is via
netvsc_probe, add the lock exclusivly for that path.

Also, clean up the unregistration path by removing the unnecessary call to
netvsc_vf_setxdp(), since unregister_netdevice_many_notify() already
performs this cleanup via dev_xdp_uninstall().

Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf")
Cc: stable@vger.kernel.org
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Tested-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>
Link: https://patch.msgid.link/1748513910-23963-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: annotate data-races around cleanup_net_task 2025-06-19T13:40:45+00:00 Eric Dumazet edumazet@google.com 2025-06-04T09:39:28+00:00 7acb2f063fc5ef0767b2594fd48d039e6792872b [ Upstream commit 535caaca921c653b1f9838fbd5c4e9494cafc3d9 ] from_cleanup_net() reads cleanup_net_task locklessly. Add READ_ONCE()/WRITE_ONCE() annotations to avoid a potential KCSAN warning, even if the race is harmless. Fixes: 0734d7c3d93c ("net: expedite synchronize_net() for cleanup_net()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20250604093928.1323333-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 535caaca921c653b1f9838fbd5c4e9494cafc3d9 ]

from_cleanup_net() reads cleanup_net_task locklessly.

Add READ_ONCE()/WRITE_ONCE() annotations to avoid
a potential KCSAN warning, even if the race is harmless.

Fixes: 0734d7c3d93c ("net: expedite synchronize_net() for cleanup_net()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20250604093928.1323333-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: Lock lower level devices when updating features 2025-05-13T01:44:33+00:00 Cosmin Ratiu cratiu@nvidia.com 2025-05-09T07:28:50+00:00 af5f54b0ef9ef72d5fc7d57f0406372e8f317958 __netdev_update_features() expects the netdevice to be ops-locked, but it gets called recursively on the lower level netdevices to sync their features, and nothing locks those. This commit fixes that, with the assumption that it shouldn't be possible for both higher-level and lover-level netdevices to require the instance lock, because that would lead to lock dependency warnings. Without this, playing with higher level (e.g. vxlan) netdevices on top of netdevices with instance locking enabled can run into issues: WARNING: CPU: 59 PID: 206496 at ./include/net/netdev_lock.h:17 netif_napi_add_weight_locked+0x753/0xa60 [...] Call Trace: <TASK> mlx5e_open_channel+0xc09/0x3740 [mlx5_core] mlx5e_open_channels+0x1f0/0x770 [mlx5_core] mlx5e_safe_switch_params+0x1b5/0x2e0 [mlx5_core] set_feature_lro+0x1c2/0x330 [mlx5_core] mlx5e_handle_feature+0xc8/0x140 [mlx5_core] mlx5e_set_features+0x233/0x2e0 [mlx5_core] __netdev_update_features+0x5be/0x1670 __netdev_update_features+0x71f/0x1670 dev_ethtool+0x21c5/0x4aa0 dev_ioctl+0x438/0xae0 sock_ioctl+0x2ba/0x690 __x64_sys_ioctl+0xa78/0x1700 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations") Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250509072850.2002821-1-cratiu@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
__netdev_update_features() expects the netdevice to be ops-locked, but
it gets called recursively on the lower level netdevices to sync their
features, and nothing locks those.

This commit fixes that, with the assumption that it shouldn't be possible
for both higher-level and lover-level netdevices to require the instance
lock, because that would lead to lock dependency warnings.

Without this, playing with higher level (e.g. vxlan) netdevices on top
of netdevices with instance locking enabled can run into issues:

WARNING: CPU: 59 PID: 206496 at ./include/net/netdev_lock.h:17 netif_napi_add_weight_locked+0x753/0xa60
[...]
Call Trace:
 <TASK>
 mlx5e_open_channel+0xc09/0x3740 [mlx5_core]
 mlx5e_open_channels+0x1f0/0x770 [mlx5_core]
 mlx5e_safe_switch_params+0x1b5/0x2e0 [mlx5_core]
 set_feature_lro+0x1c2/0x330 [mlx5_core]
 mlx5e_handle_feature+0xc8/0x140 [mlx5_core]
 mlx5e_set_features+0x233/0x2e0 [mlx5_core]
 __netdev_update_features+0x5be/0x1670
 __netdev_update_features+0x71f/0x1670
 dev_ethtool+0x21c5/0x4aa0
 dev_ioctl+0x438/0xae0
 sock_ioctl+0x2ba/0x690
 __x64_sys_ioctl+0xa78/0x1700
 do_syscall_64+0x6d/0x140
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
 </TASK>

Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250509072850.2002821-1-cratiu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: add missing instance lock to dev_set_promiscuity 2025-05-07T01:52:39+00:00 Stanislav Fomichev sdf@fomichev.me 2025-05-06T01:19:19+00:00 78cd408356fe3edbac66598772fd347bf3e32c1f Accidentally spotted while trying to understand what else needs to be renamed to netif_ prefix. Most of the calls to dev_set_promiscuity are adjacent to dev_set_allmulti or dev_disable_lro so it should be safe to add the lock. Note that new netif_set_promiscuity is currently unused, the locked paths call __dev_set_promiscuity directly. Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250506011919.2882313-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Accidentally spotted while trying to understand what else needs
to be renamed to netif_ prefix. Most of the calls to dev_set_promiscuity
are adjacent to dev_set_allmulti or dev_disable_lro so it should
be safe to add the lock. Note that new netif_set_promiscuity is
currently unused, the locked paths call __dev_set_promiscuity directly.

Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250506011919.2882313-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: Lock netdevices during dev_shutdown 2025-05-07T01:31:32+00:00 Cosmin Ratiu cratiu@nvidia.com 2025-05-05T19:47:13+00:00 08e9f2d584c4732180edee4cb2dbfa7586d7d5a3 __qdisc_destroy() calls into various qdiscs .destroy() op, which in turn can call .ndo_setup_tc(), which requires the netdev instance lock. This commit extends the critical section in unregister_netdevice_many_notify() to cover dev_shutdown() (and dev_tcx_uninstall() as a side-effect) and acquires the netdev instance lock in __dev_change_net_namespace() for the other dev_shutdown() call. This should now guarantee that for all qdisc ops, the netdev instance lock is held during .ndo_setup_tc(). Fixes: a0527ee2df3f ("net: hold netdev instance lock during qdisc ndo_setup_tc") Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250505194713.1723399-1-cratiu@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
__qdisc_destroy() calls into various qdiscs .destroy() op, which in turn
can call .ndo_setup_tc(), which requires the netdev instance lock.

This commit extends the critical section in
unregister_netdevice_many_notify() to cover dev_shutdown() (and
dev_tcx_uninstall() as a side-effect) and acquires the netdev instance
lock in __dev_change_net_namespace() for the other dev_shutdown() call.

This should now guarantee that for all qdisc ops, the netdev instance
lock is held during .ndo_setup_tc().

Fixes: a0527ee2df3f ("net: hold netdev instance lock during qdisc ndo_setup_tc")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250505194713.1723399-1-cratiu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: don't try to ops lock uninitialized devs 2025-04-17T01:28:11+00:00 Jakub Kicinski kuba@kernel.org 2025-04-15T15:15:52+00:00 4798cfa2097f0833d54d8f5ce20ef14631917839 We need to be careful when operating on dev while in rtnl_create_link(). Some devices (vxlan) initialize netdev_ops in ->newlink, so later on. Avoid using netdev_lock_ops(), the device isn't registered so we cannot legally call its ops or generate any notifications for it. netdev_ops_assert_locked_or_invisible() is safe to use, it checks registration status first. Reported-by: syzbot+de1c7d68a10e3f123bdd@syzkaller.appspotmail.com Fixes: 04efcee6ef8d ("net: hold instance lock during NETDEV_CHANGE") Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250415151552.768373-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
We need to be careful when operating on dev while in rtnl_create_link().
Some devices (vxlan) initialize netdev_ops in ->newlink, so later on.
Avoid using netdev_lock_ops(), the device isn't registered so we
cannot legally call its ops or generate any notifications for it.

netdev_ops_assert_locked_or_invisible() is safe to use, it checks
registration status first.

Reported-by: syzbot+de1c7d68a10e3f123bdd@syzkaller.appspotmail.com
Fixes: 04efcee6ef8d ("net: hold instance lock during NETDEV_CHANGE")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250415151552.768373-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: don't mix device locking in dev_close_many() calls 2025-04-14T19:48:44+00:00 Jakub Kicinski kuba@kernel.org 2025-04-12T23:30:11+00:00 f0433eea468810aebd61d0b9d095e9acd6bea2ed Lockdep found the following dependency: &dev_instance_lock_key#3 --> &rdev->wiphy.mtx --> &net->xdp.lock --> &xs->mutex --> &dev_instance_lock_key#3 The first dependency is the problem. wiphy mutex should be outside the instance locks. The problem happens in notifiers (as always) for CLOSE. We only hold the instance lock for ops locked devices during CLOSE, and WiFi netdevs are not ops locked. Unfortunately, when we dev_close_many() during netns dismantle we may be holding the instance lock of _another_ netdev when issuing a CLOSE for a WiFi device. Lockdep's "Possible unsafe locking scenario" only prints 3 locks and we have 4, plus I think we'd need 3 CPUs, like this: CPU0 CPU1 CPU2 ---- ---- ---- lock(&xs->mutex); lock(&dev_instance_lock_key#3); lock(&rdev->wiphy.mtx); lock(&net->xdp.lock); lock(&xs->mutex); lock(&rdev->wiphy.mtx); lock(&dev_instance_lock_key#3); Tho, I don't think that's possible as CPU1 and CPU2 would be under rtnl_lock. Even if we have per-netns rtnl_lock and wiphy can span network namespaces - CPU0 and CPU1 must be in the same netns to see dev_instance_lock, so CPU0 can't be installing a socket as CPU1 is tearing the netns down. Regardless, our expected lock ordering is that wiphy lock is taken before instance locks, so let's fix this. Go over the ops locked and non-locked devices separately. Note that calling dev_close_many() on an empty list is perfectly fine. All processing (including RCU syncs) are conditional on the list not being empty, already. Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations") Reported-by: syzbot+6f588c78bf765b62b450@syzkaller.appspotmail.com Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250412233011.309762-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Lockdep found the following dependency:

  &dev_instance_lock_key#3 -->
     &rdev->wiphy.mtx -->
        &net->xdp.lock -->
	   &xs->mutex -->
	      &dev_instance_lock_key#3

The first dependency is the problem. wiphy mutex should be outside
the instance locks. The problem happens in notifiers (as always)
for CLOSE. We only hold the instance lock for ops locked devices
during CLOSE, and WiFi netdevs are not ops locked. Unfortunately,
when we dev_close_many() during netns dismantle we may be holding
the instance lock of _another_ netdev when issuing a CLOSE for
a WiFi device.

Lockdep's "Possible unsafe locking scenario" only prints 3 locks
and we have 4, plus I think we'd need 3 CPUs, like this:

       CPU0                 CPU1              CPU2
       ----                 ----              ----
  lock(&xs->mutex);
                       lock(&dev_instance_lock_key#3);
                                         lock(&rdev->wiphy.mtx);
                                         lock(&net->xdp.lock);
                                         lock(&xs->mutex);
                       lock(&rdev->wiphy.mtx);
  lock(&dev_instance_lock_key#3);

Tho, I don't think that's possible as CPU1 and CPU2 would
be under rtnl_lock. Even if we have per-netns rtnl_lock and
wiphy can span network namespaces - CPU0 and CPU1 must be
in the same netns to see dev_instance_lock, so CPU0 can't
be installing a socket as CPU1 is tearing the netns down.

Regardless, our expected lock ordering is that wiphy lock
is taken before instance locks, so let's fix this.

Go over the ops locked and non-locked devices separately.
Note that calling dev_close_many() on an empty list is perfectly
fine. All processing (including RCU syncs) are conditional
on the list not being empty, already.

Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations")
Reported-by: syzbot+6f588c78bf765b62b450@syzkaller.appspotmail.com
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250412233011.309762-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: hold instance lock during NETDEV_CHANGE 2025-04-07T18:13:39+00:00 Stanislav Fomichev sdf@fomichev.me 2025-04-04T16:11:22+00:00 04efcee6ef8d0f01eef495db047e7216d6e6e38f Cosmin reports an issue with ipv6_add_dev being called from NETDEV_CHANGE notifier: [ 3455.008776] ? ipv6_add_dev+0x370/0x620 [ 3455.010097] ipv6_find_idev+0x96/0xe0 [ 3455.010725] addrconf_add_dev+0x1e/0xa0 [ 3455.011382] addrconf_init_auto_addrs+0xb0/0x720 [ 3455.013537] addrconf_notify+0x35f/0x8d0 [ 3455.014214] notifier_call_chain+0x38/0xf0 [ 3455.014903] netdev_state_change+0x65/0x90 [ 3455.015586] linkwatch_do_dev+0x5a/0x70 [ 3455.016238] rtnl_getlink+0x241/0x3e0 [ 3455.019046] rtnetlink_rcv_msg+0x177/0x5e0 Similarly, linkwatch might get to ipv6_add_dev without ops lock: [ 3456.656261] ? ipv6_add_dev+0x370/0x620 [ 3456.660039] ipv6_find_idev+0x96/0xe0 [ 3456.660445] addrconf_add_dev+0x1e/0xa0 [ 3456.660861] addrconf_init_auto_addrs+0xb0/0x720 [ 3456.661803] addrconf_notify+0x35f/0x8d0 [ 3456.662236] notifier_call_chain+0x38/0xf0 [ 3456.662676] netdev_state_change+0x65/0x90 [ 3456.663112] linkwatch_do_dev+0x5a/0x70 [ 3456.663529] __linkwatch_run_queue+0xeb/0x200 [ 3456.663990] linkwatch_event+0x21/0x30 [ 3456.664399] process_one_work+0x211/0x610 [ 3456.664828] worker_thread+0x1cc/0x380 [ 3456.665691] kthread+0xf4/0x210 Reclassify NETDEV_CHANGE as a notifier that consistently runs under the instance lock. Link: https://lore.kernel.org/netdev/aac073de8beec3e531c86c101b274d434741c28e.camel@nvidia.com/ Reported-by: Cosmin Ratiu <cratiu@nvidia.com> Tested-by: Cosmin Ratiu <cratiu@nvidia.com> Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250404161122.3907628-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Cosmin reports an issue with ipv6_add_dev being called from
NETDEV_CHANGE notifier:

[ 3455.008776]  ? ipv6_add_dev+0x370/0x620
[ 3455.010097]  ipv6_find_idev+0x96/0xe0
[ 3455.010725]  addrconf_add_dev+0x1e/0xa0
[ 3455.011382]  addrconf_init_auto_addrs+0xb0/0x720
[ 3455.013537]  addrconf_notify+0x35f/0x8d0
[ 3455.014214]  notifier_call_chain+0x38/0xf0
[ 3455.014903]  netdev_state_change+0x65/0x90
[ 3455.015586]  linkwatch_do_dev+0x5a/0x70
[ 3455.016238]  rtnl_getlink+0x241/0x3e0
[ 3455.019046]  rtnetlink_rcv_msg+0x177/0x5e0

Similarly, linkwatch might get to ipv6_add_dev without ops lock:
[ 3456.656261]  ? ipv6_add_dev+0x370/0x620
[ 3456.660039]  ipv6_find_idev+0x96/0xe0
[ 3456.660445]  addrconf_add_dev+0x1e/0xa0
[ 3456.660861]  addrconf_init_auto_addrs+0xb0/0x720
[ 3456.661803]  addrconf_notify+0x35f/0x8d0
[ 3456.662236]  notifier_call_chain+0x38/0xf0
[ 3456.662676]  netdev_state_change+0x65/0x90
[ 3456.663112]  linkwatch_do_dev+0x5a/0x70
[ 3456.663529]  __linkwatch_run_queue+0xeb/0x200
[ 3456.663990]  linkwatch_event+0x21/0x30
[ 3456.664399]  process_one_work+0x211/0x610
[ 3456.664828]  worker_thread+0x1cc/0x380
[ 3456.665691]  kthread+0xf4/0x210

Reclassify NETDEV_CHANGE as a notifier that consistently runs under the
instance lock.

Link: https://lore.kernel.org/netdev/aac073de8beec3e531c86c101b274d434741c28e.camel@nvidia.com/
Reported-by: Cosmin Ratiu <cratiu@nvidia.com>
Tested-by: Cosmin Ratiu <cratiu@nvidia.com>
Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250404161122.3907628-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: use netif_disable_lro in ipv6_add_dev 2025-04-03T22:32:08+00:00 Stanislav Fomichev sdf@fomichev.me 2025-04-01T16:34:44+00:00 8965c160b8f7333df895321c8aa6bad4a7175f2b ipv6_add_dev might call dev_disable_lro which unconditionally grabs instance lock, so it will deadlock during NETDEV_REGISTER. Switch to netif_disable_lro. Make sure all callers hold the instance lock as well. Cc: Cosmin Ratiu <cratiu@nvidia.com> Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250401163452.622454-4-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
ipv6_add_dev might call dev_disable_lro which unconditionally grabs
instance lock, so it will deadlock during NETDEV_REGISTER. Switch
to netif_disable_lro.

Make sure all callers hold the instance lock as well.

Cc: Cosmin Ratiu <cratiu@nvidia.com>
Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250401163452.622454-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: hold instance lock during NETDEV_REGISTER/UP 2025-04-03T22:32:08+00:00 Stanislav Fomichev sdf@fomichev.me 2025-04-01T16:34:43+00:00 4c975fd700022c90e61a46326e3444e08317876e Callers of inetdev_init can come from several places with inconsistent expectation about netdev instance lock. Grab instance lock during REGISTER (plus UP). Also solve the inconsistency with UNREGISTER where it was locked only during move netns path. WARNING: CPU: 10 PID: 1479 at ./include/net/netdev_lock.h:54 __netdev_update_features+0x65f/0xca0 __warn+0x81/0x180 __netdev_update_features+0x65f/0xca0 report_bug+0x156/0x180 handle_bug+0x4f/0x90 exc_invalid_op+0x13/0x60 asm_exc_invalid_op+0x16/0x20 __netdev_update_features+0x65f/0xca0 netif_disable_lro+0x30/0x1d0 inetdev_init+0x12f/0x1f0 inetdev_event+0x48b/0x870 notifier_call_chain+0x38/0xf0 register_netdevice+0x741/0x8b0 register_netdev+0x1f/0x40 mlx5e_probe+0x4e3/0x8e0 [mlx5_core] auxiliary_bus_probe+0x3f/0x90 really_probe+0xc3/0x3a0 __driver_probe_device+0x80/0x150 driver_probe_device+0x1f/0x90 __device_attach_driver+0x7d/0x100 bus_for_each_drv+0x80/0xd0 __device_attach+0xb4/0x1c0 bus_probe_device+0x91/0xa0 device_add+0x657/0x870 Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reported-by: Cosmin Ratiu <cratiu@nvidia.com> Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250401163452.622454-3-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Callers of inetdev_init can come from several places with inconsistent
expectation about netdev instance lock. Grab instance lock during
REGISTER (plus UP). Also solve the inconsistency with UNREGISTER
where it was locked only during move netns path.

WARNING: CPU: 10 PID: 1479 at ./include/net/netdev_lock.h:54
__netdev_update_features+0x65f/0xca0
__warn+0x81/0x180
__netdev_update_features+0x65f/0xca0
report_bug+0x156/0x180
handle_bug+0x4f/0x90
exc_invalid_op+0x13/0x60
asm_exc_invalid_op+0x16/0x20
__netdev_update_features+0x65f/0xca0
netif_disable_lro+0x30/0x1d0
inetdev_init+0x12f/0x1f0
inetdev_event+0x48b/0x870
notifier_call_chain+0x38/0xf0
register_netdevice+0x741/0x8b0
register_netdev+0x1f/0x40
mlx5e_probe+0x4e3/0x8e0 [mlx5_core]
auxiliary_bus_probe+0x3f/0x90
really_probe+0xc3/0x3a0
__driver_probe_device+0x80/0x150
driver_probe_device+0x1f/0x90
__device_attach_driver+0x7d/0x100
bus_for_each_drv+0x80/0xd0
__device_attach+0xb4/0x1c0
bus_probe_device+0x91/0xa0
device_add+0x657/0x870

Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Cosmin Ratiu <cratiu@nvidia.com>
Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250401163452.622454-3-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>