Re: [PATCH -next V5 1/2] sata_fsl: fix UAF in sata_fsl_port_stop when rmmod sata_fsl

[libaokun (A)]

在 2021/11/27 3:43, Sergei Shtylyov 写道:
> On 11/26/21 5:03 AM, Baokun Li wrote:
>
> > When the `rmmod sata_fsl.ko` command is executed in the PPC64 GNU/Linux,
> > a bug is reported:
> >   ==================================================================
> >   BUG: Unable to handle kernel data access on read at 0x80000800805b502c
> >   Oops: Kernel access of bad area, sig: 11 [#1]
> >   NIP [c0000000000388a4] .ioread32+0x4/0x20
> >   LR [80000000000c6034] .sata_fsl_port_stop+0x44/0xe0 [sata_fsl]
> >   Call Trace:
> >    .free_irq+0x1c/0x4e0 (unreliable)
> >    .ata_host_stop+0x74/0xd0 [libata]
> >    .release_nodes+0x330/0x3f0
> >    .device_release_driver_internal+0x178/0x2c0
> >    .driver_detach+0x64/0xd0
> >    .bus_remove_driver+0x70/0xf0
> >    .driver_unregister+0x38/0x80
> >    .platform_driver_unregister+0x14/0x30
> >    .fsl_sata_driver_exit+0x18/0xa20 [sata_fsl]
> >    .__se_sys_delete_module+0x1ec/0x2d0
> >    .system_call_exception+0xfc/0x1f0
> >    system_call_common+0xf8/0x200
> >   ==================================================================
> >
> > The triggering of the BUG is shown in the following stack:
> >
> > driver_detach
> >    device_release_driver_internal
> >      __device_release_driver
> >        drv->remove(dev) --> platform_drv_remove/platform_remove
> >          drv->remove(dev) --> sata_fsl_remove
> >            iounmap(host_priv->hcr_base);			<---- unmap
> >            kfree(host_priv);                             <---- free
> >        devres_release_all
> >          release_nodes
> >            dr->node.release(dev, dr->data) --> ata_host_stop
> >              ap->ops->port_stop(ap) --> sata_fsl_port_stop
> >                  ioread32(hcr_base + HCONTROL)           <---- UAF
> >              host->ops->host_stop(host)
> >
> > The iounmap(host_priv->hcr_base) and kfree(host_priv) functions should
> > not be executed in drv->remove. These functions should be executed in
> > host_stop after port_stop. Therefore, we move these functions to the
> > new function sata_fsl_host_stop and bind the new function to host_stop.
> >
> > Fixes: faf0b2e5afe7 ("drivers/ata: add support to Freescale 3.0Gbps SATA Controller")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
> Reviewed-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxx>
>
> MBR, Sergei
> .

Thank you for your review.

--
With Best Regards,
Baokun Li
.