On Wed, Aug 26, 2020 at 12:40 PM Jakub Kicinski <k...@kernel.org> wrote:
>
> Netpoll can try to poll napi as soon as napi_enable() is called.
> It crashes trying to access a doorbell which is still NULL:
>
> BUG: kernel NULL pointer dereference, address: 0000000000000000
> CPU: 59 PID: 6039 Comm: ethtool Kdump: loaded Tainted: G S
> 5.9.0-rc1-00469-g5fd99b5d9950-dirty #26
> RIP: 0010:bnxt_poll+0x121/0x1c0
> Code: c4 20 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 8b 86 a0 01 00 00
> 41 23 85 18 01 00 00 49 8b 96 a8 01 00 00 0d 00 00 00 24 <89> 02
> 41 f6 45 77 02 74 cb 49 8b ae d8 01 00 00 31 c0 c7 44 24 1a
> netpoll_poll_dev+0xbd/0x1a0
> __netpoll_send_skb+0x1b2/0x210
> netpoll_send_udp+0x2c9/0x406
> write_ext_msg+0x1d7/0x1f0
> console_unlock+0x23c/0x520
> vprintk_emit+0xe0/0x1d0
> printk+0x58/0x6f
> x86_vector_activate.cold+0xf/0x46
> __irq_domain_activate_irq+0x50/0x80
> __irq_domain_activate_irq+0x32/0x80
> __irq_domain_activate_irq+0x32/0x80
> irq_domain_activate_irq+0x25/0x40
> __setup_irq+0x2d2/0x700
> request_threaded_irq+0xfb/0x160
> __bnxt_open_nic+0x3b1/0x750
> bnxt_open_nic+0x19/0x30
> ethtool_set_channels+0x1ac/0x220
> dev_ethtool+0x11ba/0x2240
> dev_ioctl+0x1cf/0x390
> sock_do_ioctl+0x95/0x130
>
> Reported-by: Rob Sherwood <rs...@fb.com>
> Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.")
> Signed-off-by: Jakub Kicinski <k...@kernel.org>
Reviewed-by: Michael Chan <michael.c...@broadcom.com>
Thanks.
