[Intel-wired-lan] [PATCH iwl-net v5] ice: Add netif_device_attach/detach into PF reset flow

Michal Schmidt mschmidt at redhat.com
Mon Aug 26 17:25:10 UTC 2024


On Wed, Aug 21, 2024 at 6:07 PM Dawid Osuchowski
<dawid.osuchowski at linux.intel.com> wrote:
>
> Ethtool callbacks can be executed while reset is in progress and try to
> access deleted resources, e.g. getting coalesce settings can result in a
> NULL pointer dereference seen below.
>
> Reproduction steps:
> Once the driver is fully initialized, trigger reset:
>         # echo 1 > /sys/class/net/<interface>/device/reset
> when reset is in progress try to get coalesce settings using ethtool:
>         # ethtool -c <interface>
>
> BUG: kernel NULL pointer dereference, address: 0000000000000020
> PGD 0 P4D 0
> Oops: Oops: 0000 [#1] PREEMPT SMP PTI
> CPU: 11 PID: 19713 Comm: ethtool Tainted: G S                 6.10.0-rc7+ #7
> RIP: 0010:ice_get_q_coalesce+0x2e/0xa0 [ice]
> RSP: 0018:ffffbab1e9bcf6a8 EFLAGS: 00010206
> RAX: 000000000000000c RBX: ffff94512305b028 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffff9451c3f2e588 RDI: ffff9451c3f2e588
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: ffff9451c3f2e580 R11: 000000000000001f R12: ffff945121fa9000
> R13: ffffbab1e9bcf760 R14: 0000000000000013 R15: ffffffff9e65dd40
> FS:  00007faee5fbe740(0000) GS:ffff94546fd80000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000020 CR3: 0000000106c2e005 CR4: 00000000001706f0
> Call Trace:
> <TASK>
> ice_get_coalesce+0x17/0x30 [ice]
> coalesce_prepare_data+0x61/0x80
> ethnl_default_doit+0xde/0x340
> genl_family_rcv_msg_doit+0xf2/0x150
> genl_rcv_msg+0x1b3/0x2c0
> netlink_rcv_skb+0x5b/0x110
> genl_rcv+0x28/0x40
> netlink_unicast+0x19c/0x290
> netlink_sendmsg+0x222/0x490
> __sys_sendto+0x1df/0x1f0
> __x64_sys_sendto+0x24/0x30
> do_syscall_64+0x82/0x160
> entry_SYSCALL_64_after_hwframe+0x76/0x7e
> RIP: 0033:0x7faee60d8e27
>
> Calling netif_device_detach() before reset makes the net core not call
> the driver when ethtool command is issued, the attempt to execute an
> ethtool command during reset will result in the following message:
>
>     netlink error: No such device
>
> instead of NULL pointer dereference. Once reset is done and
> ice_rebuild() is executing, the netif_device_attach() is called to allow
> for ethtool operations to occur again in a safe manner.
>
> Fixes: fcea6f3da546 ("ice: Add stats and ethtool support")
> Suggested-by: Jakub Kicinski <kuba at kernel.org>
> Reviewed-by: Igor Bagnucki <igor.bagnucki at intel.com>
> Signed-off-by: Dawid Osuchowski <dawid.osuchowski at linux.intel.com>
> ---
> Changes since v1:
> * Changed Fixes tag to point to another commit
> * Minified the stacktrace
>
> Changes since v2:
> * Moved netif_device_attach() directly into ice_rebuild() and perform it
>   only on main vsi
>
> Changes since v3:
> * Style changes requested by Przemek Kitszel
>
> Changes since v4:
> * Applied reverse xmas tree rule to declaration of ice_vsi *vsi variable
>
> Suggestion from Kuba: https://lore.kernel.org/netdev/20240610194756.5be5be90@kernel.org/
> Previous attempt (dropped because it introduced regression with link up): https://lore.kernel.org/netdev/20240722122839.51342-1-dawid.osuchowski@linux.intel.com/

This v5 passes the tests that the previous attempt referenced above failed.
The patch looks sane.

Reviewed-by: Michal Schmidt <mschmidt at redhat.com>



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