From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bowers, AndrewX Date: Wed, 28 Aug 2019 16:23:46 +0000 Subject: [Intel-wired-lan] [PATCH] i40e: check __I40E_VF_DISABLE bit in i40e_sync_filters_subtask In-Reply-To: <20190821140929.26985-1-sassmann@kpanic.de> References: <20190821140929.26985-1-sassmann@kpanic.de> Message-ID: <094c89e92baa4f5e96ffb766263ce07f@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: > -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces at osuosl.org] On > Behalf Of Stefan Assmann > Sent: Wednesday, August 21, 2019 7:09 AM > To: intel-wired-lan at lists.osuosl.org > Cc: netdev at vger.kernel.org; davem at davemloft.net; sassmann at kpanic.de > Subject: [Intel-wired-lan] [PATCH] i40e: check __I40E_VF_DISABLE bit in > i40e_sync_filters_subtask > > While testing VF spawn/destroy the following panic occured. > > BUG: unable to handle kernel NULL pointer dereference at > 0000000000000029 [...] > Workqueue: i40e i40e_service_task [i40e] > RIP: 0010:i40e_sync_vsi_filters+0x6fd/0xc60 [i40e] [...] Call Trace: > ? __switch_to_asm+0x35/0x70 > ? __switch_to_asm+0x41/0x70 > ? __switch_to_asm+0x35/0x70 > ? _cond_resched+0x15/0x30 > i40e_sync_filters_subtask+0x56/0x70 [i40e] > i40e_service_task+0x382/0x11b0 [i40e] > ? __switch_to_asm+0x41/0x70 > ? __switch_to_asm+0x41/0x70 > process_one_work+0x1a7/0x3b0 > worker_thread+0x30/0x390 > ? create_worker+0x1a0/0x1a0 > kthread+0x112/0x130 > ? kthread_bind+0x30/0x30 > ret_from_fork+0x35/0x40 > > Investigation revealed a race where pf->vf[vsi->vf_id].trusted may get > accessed by the watchdog via i40e_sync_filters_subtask() although > i40e_free_vfs() already free'd pf->vf. > To avoid this the call to i40e_sync_vsi_filters() in > i40e_sync_filters_subtask() needs to be guarded by __I40E_VF_DISABLE, > which is also used by i40e_free_vfs(). > > Note: put the __I40E_VF_DISABLE check after the > __I40E_MACVLAN_SYNC_PENDING check as the latter is more likely to > trigger. > > Signed-off-by: Stefan Assmann > --- > drivers/net/ethernet/intel/i40e/i40e_main.c | 5 +++++ > 1 file changed, 5 insertions(+) Tested-by: Andrew Bowers