RE: [PATCH] spi: fsl-dspi: fix NULL pointer dereference

[Qiang Zhao <qiang.zhao@xxxxxxx>]

On Thu, Oct 29, 2020 at 19:03PM, Vladimir Oltean <olteanv@xxxxxxxxx> wrote:


> -----Original Message-----
> From: Vladimir Oltean <olteanv@xxxxxxxxx>
> Sent: 2020年10月29日 19:03
> To: Qiang Zhao <qiang.zhao@xxxxxxx>
> Cc: broonie@xxxxxxxxxx; linux-spi@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] spi: fsl-dspi: fix NULL pointer dereference
> 
> On Thu, Oct 29, 2020 at 04:40:35PM +0800, Qiang Zhao wrote:
> > From: Zhao Qiang <qiang.zhao@xxxxxxx>
> >
> > Since commit 530b5affc675 ("spi: fsl-dspi: fix use-after-free in
> > remove path"), this driver causes a kernel oops:
> >
> > [   64.587431] Unable to handle kernel NULL pointer dereference at
> > virtual address 0000000000000020
> > [..]
> > [   64.756080] Call trace:
> > [   64.758526]  dspi_suspend+0x30/0x78
> > [   64.762012]  platform_pm_suspend+0x28/0x70
> > [   64.766107]  dpm_run_callback.isra.19+0x24/0x70
> > [   64.770635]  __device_suspend+0xf4/0x2f0
> > [   64.774553]  dpm_suspend+0xec/0x1e0
> > [   64.778036]  dpm_suspend_start+0x80/0xa0
> > [   64.781957]  suspend_devices_and_enter+0x118/0x4f0
> > [   64.786743]  pm_suspend+0x1e0/0x260
> > [   64.790227]  state_store+0x8c/0x118
> > [   64.793712]  kobj_attr_store+0x18/0x30
> > [   64.797459]  sysfs_kf_write+0x40/0x58
> > [   64.801118]  kernfs_fop_write+0x148/0x240
> > [   64.805126]  vfs_write+0xc0/0x230
> > [   64.808436]  ksys_write+0x6c/0x100
> > [   64.811833]  __arm64_sys_write+0x1c/0x28
> > [   64.815753]  el0_svc_common.constprop.3+0x68/0x170
> > [   64.820541]  do_el0_svc+0x24/0x90
> > [   64.823853]  el0_sync_handler+0x118/0x168
> > [   64.827858]  el0_sync+0x158/0x180
> >
> > This is because since this commit, the drivers private data point to
> > "dspi" instead of "ctlr", the codes in suspend and resume func were
> > not modified correspondly.
> >
> > Fixes: 530b5affc675 ("spi: fsl-dspi: fix use-after-free in remove
> > path")
> > Signed-off-by: Zhao Qiang <qiang.zhao@xxxxxxx>
> > ---
> 
> Please update your tree.
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.c
> om%2Ftorvalds%2Flinux%2Fcommit%2F6e3837668e00fb914ac2b43158ef51b0
> 27ec385c&amp;data=04%7C01%7Cqiang.zhao%40nxp.com%7C50171bf65a5e
> 4f24e0c208d87bfa3fe9%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0
> %7C637395662023835048%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjA
> wMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sda
> ta=NlmOj1SfvKu2V7nrSYF3lDji25xbP5PeDl1PcwlKyr4%3D&amp;reserved=0

I saw the patch, it just fix the issue when the kernel are booted up.
But there still have the issue when the driver suspend and resume. 

Best Regards
Qiang Zhao