Messages in this thread | | | Date | Sat, 20 Nov 2021 15:01:43 +0300 | Subject | Re: [PATCH -next V2 1/2] sata_fsl: fix UAF in sata_fsl_port_stop when rmmod sata_fsl | From | Sergei Shtylyov <> |
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Hello!
On 20.11.2021 6:34, 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) commands should
s/commands/functions/?
> not be executed in drv->remove. These commands should be executed in > host_stop after port_stop. Therefore, we move these commands to the > new function sata_fsl_host_stop and bind the new function to host_stop > by referring to achi.
You mean AHCI? I don't see where you reference ahci (or achi)...
> Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Baokun Li <libaokun1@huawei.com>
Doesn't this need to go into the stable trees?
> --- > drivers/ata/sata_fsl.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c > index e5838b23c9e0..30759fd1c3a2 100644 > --- a/drivers/ata/sata_fsl.c > +++ b/drivers/ata/sata_fsl.c > @@ -1430,12 +1430,25 @@ static struct ata_port_operations sata_fsl_ops = { > .pmp_detach = sata_fsl_pmp_detach, > }; > > +static void sata_fsl_host_stop(struct ata_host *host) > +{ > + struct sata_fsl_host_priv *host_priv = host->private_data; > + > + iounmap(host_priv->hcr_base); > + kfree(host_priv); > +} > + > +static struct ata_port_operations sata_fsl_platform_ops = { > + .inherits = &sata_fsl_ops, > + .host_stop = sata_fsl_host_stop,
Why not just add it to the initializer for sata_fsl_ops?
[...]
MBR, Sergei
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