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; }