This is a note to let you know that I've just added the patch titled
PCI: switchtec: Return -EFAULT for copy_to_user() errors
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-switchtec-return-efault-for-copy_to_user-errors.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 27e415dafbdf58afabdb935cf511ed4f1802377e
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Fri Dec 16 10:21:26 2022 -0600
PCI: switchtec: Return -EFAULT for copy_to_user() errors
[ Upstream commit ddc10938e08cd7aac63d8385f7305f7889df5179 ]
switchtec_dev_read() didn't handle copy_to_user() errors correctly: it
assigned "rc = -EFAULT", but actually returned either "size", -ENXIO, or
-EBADMSG instead.
Update the failure cases to unlock mrpc_mutex and return -EFAULT directly.
Link: https://lore.kernel.org/r/20221216162126.207863-3-helgaas@xxxxxxxxxx
Fixes: 080b47def5e5 ("MicroSemi Switchtec management interface driver")
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index 0b301f8be9ed5..d021ef3fb165b 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -552,21 +552,20 @@ static ssize_t switchtec_dev_read(struct file *filp, char __user *data,
rc = copy_to_user(data, &stuser->return_code,
sizeof(stuser->return_code));
if (rc) {
- rc = -EFAULT;
- goto out;
+ mutex_unlock(&stdev->mrpc_mutex);
+ return -EFAULT;
}
data += sizeof(stuser->return_code);
rc = copy_to_user(data, &stuser->data,
size - sizeof(stuser->return_code));
if (rc) {
- rc = -EFAULT;
- goto out;
+ mutex_unlock(&stdev->mrpc_mutex);
+ return -EFAULT;
}
stuser_set_state(stuser, MRPC_IDLE);
-out:
mutex_unlock(&stdev->mrpc_mutex);
if (stuser->status == SWITCHTEC_MRPC_STATUS_DONE)
