[PATCH 5.4 30/70] sata_fsl: fix UAF in sata_fsl_port_stop when rmmod sata_fsl

Greg Kroah-Hartman
2021-12-06T15:25:11Z

From: Baokun Li <libaokun1@huawei.com>

commit 6c8ad7e8cf29eb55836e7a0215f967746ab2b504 upstream.

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@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/ata/sata_fsl.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -1394,6 +1394,14 @@ static int sata_fsl_init_controller(stru
return 0;
}

+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);
+}
+
/*
* scsi mid-layer and libata interface structures
*/
@@ -1426,6 +1434,8 @@ static struct ata_port_operations sata_f
.port_start = sata_fsl_port_start,
.port_stop = sata_fsl_port_stop,

+ .host_stop = sata_fsl_host_stop,
+
.pmp_attach = sata_fsl_pmp_attach,
.pmp_detach = sata_fsl_pmp_detach,
};
@@ -1558,8 +1568,6 @@ static int sata_fsl_remove(struct platfo
ata_host_detach(host);

irq_dispose_mapping(host_priv->irq);
- iounmap(host_priv->hcr_base);
- kfree(host_priv);

return 0;
}