[PATCH -next V3 0/2] fix two bugs when trying rmmod sata_fsl

[PATCH -next V3 0/2] fix two bugs when trying rmmod sata_fsl

[Baokun Li]

V1->V2:
	Fixed the check on the return value of platform_get_irq().
	And propagate errors up to sata_fsl_probe()'s callers.
V2->V3:
	Add fixed and CC stable and modified the patch description.

Baokun Li (2):
  sata_fsl: fix UAF in sata_fsl_port_stop when rmmod sata_fsl
  sata_fsl: fix warning in remove_proc_entry when rmmod sata_fsl

 drivers/ata/sata_fsl.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

-- 
2.31.1

[PATCH -next V3 1/2] sata_fsl: fix UAF in sata_fsl_port_stop when rmmod sata_fsl

[Baokun Li]

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
by referring to AHCI.

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>
---
V2->V3:
	Add fixed and CC stable and modified the patch description.

 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,
+};
+
 static const struct ata_port_info sata_fsl_port_info[] = {
 	{
 	 .flags = SATA_FSL_HOST_FLAGS,
 	 .pio_mask = ATA_PIO4,
 	 .udma_mask = ATA_UDMA6,
-	 .port_ops = &sata_fsl_ops,
+	 .port_ops = &sata_fsl_platform_ops,
 	 },
 };
 
@@ -1558,8 +1571,6 @@ static int sata_fsl_remove(struct platform_device *ofdev)
 	ata_host_detach(host);
 
 	irq_dispose_mapping(host_priv->irq);
-	iounmap(host_priv->hcr_base);
-	kfree(host_priv);
 
 	return 0;
 }
-- 
2.31.1

[PATCH -next V3 2/2] sata_fsl: fix warning in remove_proc_entry when rmmod sata_fsl

[Baokun Li]

Trying to remove the fsl-sata module in the PPC64 GNU/Linux
leads to the following warning:
 ------------[ cut here ]------------
 remove_proc_entry: removing non-empty directory 'irq/69',
   leaking at least 'fsl-sata[ff0221000.sata]'
 WARNING: CPU: 3 PID: 1048 at fs/proc/generic.c:722
   .remove_proc_entry+0x20c/0x220
 IRQMASK: 0
 NIP [c00000000033826c] .remove_proc_entry+0x20c/0x220
 LR [c000000000338268] .remove_proc_entry+0x208/0x220
 Call Trace:
  .remove_proc_entry+0x208/0x220 (unreliable)
  .unregister_irq_proc+0x104/0x140
  .free_desc+0x44/0xb0
  .irq_free_descs+0x9c/0xf0
  .irq_dispose_mapping+0x64/0xa0
  .sata_fsl_remove+0x58/0xa0 [sata_fsl]
  .platform_drv_remove+0x40/0x90
  .device_release_driver_internal+0x160/0x2c0
  .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]
 ---[ end trace 0ea876d4076908f5 ]---

The driver creates the mapping by calling irq_of_parse_and_map(),
so it also has to dispose the mapping. But the easy way out is to
simply use platform_get_irq() instead of irq_of_parse_map(). Also
we should adapt return value checking and propagate error values.

In this case the mapping is not managed by the device but by
the of core, so the device has not to dispose the mapping.

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>
---
V1->V2:
	Adapt return value checking and propagate error values.
V2->V3:
	Add fixed and CC stable.

 drivers/ata/sata_fsl.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index 30759fd1c3a2..f850dfab72a6 100644
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -1493,8 +1493,9 @@ static int sata_fsl_probe(struct platform_device *ofdev)
 	host_priv->ssr_base = ssr_base;
 	host_priv->csr_base = csr_base;
 
-	irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
-	if (!irq) {
+	irq = platform_get_irq(ofdev, 0);
+	if (irq < 0) {
+		retval = irq;
 		dev_err(&ofdev->dev, "invalid irq from platform\n");
 		goto error_exit_with_cleanup;
 	}
@@ -1570,8 +1571,6 @@ static int sata_fsl_remove(struct platform_device *ofdev)
 
 	ata_host_detach(host);
 
-	irq_dispose_mapping(host_priv->irq);
-
 	return 0;
 }
 
-- 
2.31.1