在 2021/11/22 10:33, Damien Le Moal 写道:
On 2021/11/22 11:03, libaokun (A) wrote:
在 2021/11/20 20:01, Sergei Shtylyov 写道:
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/?
OK! I'm going to modify this in V3.
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)...
Yes, it's AHCI, I'm sorry for a spelling error here..
ahci_platform_ops in drivers/ata/libahci_platform.c
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
Doesn't this need to go into the stable trees?
I felt it was needed because the bug was triggered in a very simple way,
although PPC linux is rare these days.
And I will add
Fixes: faf0b2e5afe7 ("drivers/ata: add support to Freescale 3.0Gbps SATA Controller").
Also add:
Cc: stable@xxxxxxxxxxxxxxx
---
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?
This is the AHCI of the reference.
Most ATA drivers add host_stop to to the initializer for xxx_platform_ops,
such as ahci_platform_ops, ahci_brcm_platform_ops, and ahci_imx_ops.
It feels like this separates the port operation from the host operation,
making the hierarchy of the code clearer.
[...]
MBR, Sergei
.
Thank you very much for your advice.
If there's nothing else to modify, I'll send a patch V3.
--
With Best Regards,
Baokun Li
.
Thank you very much for your advice.
I'm about to send a patch V3 with the changes suggested by you.
--
With Best Regards,
Baokun Li
.
