From: Breno Leitao <leitao@debian.org>
To: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Lunn <andrew@lunn.ch>, Jakub Kicinski <kuba@kernel.org>,
David Miller <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
Maxime Chevallier <maxime.chevallier@bootlin.com>,
Michal Kubecek <mkubecek@suse.cz>, Gal Pressman <gal@nvidia.com>,
Kory Maincent <kory.maincent@bootlin.com>,
Oleksij Rempel <o.rempel@pengutronix.de>,
Ido Schimmel <idosch@nvidia.com>,
Heiner Kallweit <hkallweit1@gmail.com>,
Greg KH <gregkh@linuxfoundation.org>,
Johannes Berg <johannes@sipsolutions.net>,
James Guan <guan_yufei@163.com>, Kees Cook <kees@kernel.org>,
Paul Moses <p@1g4.org>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, security@kernel.org,
notify@kernel.org
Subject: Re: [PATCH] wifi: virt_wifi: remove SET_NETDEV_DEV to avoid use-after-free
Date: Wed, 25 Mar 2026 02:23:05 -0700 [thread overview]
Message-ID: <acOpZ76jptETE7Bd@gmail.com> (raw)
In-Reply-To: <20260324224607.374327-1-alex.popov@linux.com>
On Wed, Mar 25, 2026 at 01:46:02AM +0300, Alexander Popov wrote:
> Currently we execute `SET_NETDEV_DEV(dev, &priv->lowerdev->dev)` for
> the virt_wifi net devices. However, unregistering a virt_wifi device in
> netdev_run_todo() can happen together with the device referenced by
> SET_NETDEV_DEV().
>
> It can result in use-after-free during the ethtool operations performed
> on a virt_wifi device that is currently being unregistered. Such a net
> device can have the `dev.parent` field pointing to the freed memory,
> but ethnl_ops_begin() calls `pm_runtime_get_sync(dev->dev.parent)`.
>
> Let's remove SET_NETDEV_DEV for virt_wifi to avoid bugs like this:
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in __pm_runtime_resume+0xe2/0xf0
> Read of size 2 at addr ffff88810cfc46f8 by task pm/606
>
> Call Trace:
> <TASK>
> dump_stack_lvl+0x4d/0x70
> print_report+0x170/0x4f3
> ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> kasan_report+0xda/0x110
> ? __pm_runtime_resume+0xe2/0xf0
> ? __pm_runtime_resume+0xe2/0xf0
> __pm_runtime_resume+0xe2/0xf0
> ethnl_ops_begin+0x49/0x270
> ethnl_set_features+0x23c/0xab0
> ? __pfx_ethnl_set_features+0x10/0x10
> ? kvm_sched_clock_read+0x11/0x20
> ? local_clock_noinstr+0xf/0xf0
> ? local_clock+0x10/0x30
> ? kasan_save_track+0x25/0x60
> ? __kasan_kmalloc+0x7f/0x90
> ? genl_family_rcv_msg_attrs_parse.isra.0+0x150/0x2c0
> genl_family_rcv_msg_doit+0x1e7/0x2c0
> ? __pfx_genl_family_rcv_msg_doit+0x10/0x10
> ? __pfx_cred_has_capability.isra.0+0x10/0x10
> ? stack_trace_save+0x8e/0xc0
> genl_rcv_msg+0x411/0x660
> ? __pfx_genl_rcv_msg+0x10/0x10
> ? __pfx_ethnl_set_features+0x10/0x10
> netlink_rcv_skb+0x121/0x380
> ? __pfx_genl_rcv_msg+0x10/0x10
> ? __pfx_netlink_rcv_skb+0x10/0x10
> ? __pfx_down_read+0x10/0x10
> genl_rcv+0x23/0x30
> netlink_unicast+0x60f/0x830
> ? __pfx_netlink_unicast+0x10/0x10
> ? __pfx___alloc_skb+0x10/0x10
> netlink_sendmsg+0x6ea/0xbc0
> ? __pfx_netlink_sendmsg+0x10/0x10
> ? __futex_queue+0x10b/0x1f0
> ____sys_sendmsg+0x7a2/0x950
> ? copy_msghdr_from_user+0x26b/0x430
> ? __pfx_____sys_sendmsg+0x10/0x10
> ? __pfx_copy_msghdr_from_user+0x10/0x10
> ___sys_sendmsg+0xf8/0x180
> ? __pfx____sys_sendmsg+0x10/0x10
> ? __pfx_futex_wait+0x10/0x10
> ? fdget+0x2e4/0x4a0
> __sys_sendmsg+0x11f/0x1c0
> ? __pfx___sys_sendmsg+0x10/0x10
> do_syscall_64+0xe2/0x570
> ? exc_page_fault+0x66/0xb0
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> </TASK>
>
> This fix may be combined with another one in the ethtool subsystem:
> https://lore.kernel.org/all/20260322075917.254874-1-alex.popov@linux.com/T/#u
>
> Fixes: d43c65b05b848e0b ("ethtool: runtime-resume netdev parent in ethnl_ops_begin")
> Cc: stable@vger.kernel.org
> Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
next prev parent reply other threads:[~2026-03-25 9:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-24 22:46 [PATCH] wifi: virt_wifi: remove SET_NETDEV_DEV to avoid use-after-free Alexander Popov
2026-03-25 8:35 ` Greg KH
2026-03-25 9:23 ` Breno Leitao [this message]
2026-03-25 12:34 ` Andrew Lunn
2026-03-25 13:47 ` Greg KH
2026-03-25 17:24 ` Alexander Popov
-- strict thread matches above, loose matches on Subject: below --
2026-04-07 11:14 FAILED: patch "[PATCH] wifi: virt_wifi: remove SET_NETDEV_DEV to avoid" failed to apply to 6.19-stable tree gregkh
2026-04-08 6:10 ` [PATCH] wifi: virt_wifi: remove SET_NETDEV_DEV to avoid use-after-free Alexander Popov
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