From: Eddie James eajames@linux.ibm.com
[ Upstream commit d3e1e24604031b0d83b6c2d38f54eeea265cfcc0 ]
Use get_device and put_device in the open and close functions to make sure the device doesn't get freed while a file descriptor is open. Also, lock around the freeing of the device buffer and check the buffer before using it in the submit function.
Signed-off-by: Eddie James eajames@linux.ibm.com Reviewed-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20220513194424.53468-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley joel@jms.id.au Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/fsi/fsi-occ.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c index c9cc75fbdfb9..28c176d038a2 100644 --- a/drivers/fsi/fsi-occ.c +++ b/drivers/fsi/fsi-occ.c @@ -94,6 +94,7 @@ static int occ_open(struct inode *inode, struct file *file) client->occ = occ; mutex_init(&client->lock); file->private_data = client; + get_device(occ->dev);
/* We allocate a 1-page buffer, make sure it all fits */ BUILD_BUG_ON((OCC_CMD_DATA_BYTES + 3) > PAGE_SIZE); @@ -197,6 +198,7 @@ static int occ_release(struct inode *inode, struct file *file) { struct occ_client *client = file->private_data;
+ put_device(client->occ->dev); free_page((unsigned long)client->buffer); kfree(client);
@@ -493,12 +495,19 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len, for (i = 1; i < req_len - 2; ++i) checksum += byte_request[i];
- mutex_lock(&occ->occ_lock); + rc = mutex_lock_interruptible(&occ->occ_lock); + if (rc) + return rc;
occ->client_buffer = response; occ->client_buffer_size = user_resp_len; occ->client_response_size = 0;
+ if (!occ->buffer) { + rc = -ENOENT; + goto done; + } + /* * Get a sequence number and update the counter. Avoid a sequence * number of 0 which would pass the response check below even if the @@ -671,10 +680,13 @@ static int occ_remove(struct platform_device *pdev) { struct occ *occ = platform_get_drvdata(pdev);
- kvfree(occ->buffer); - misc_deregister(&occ->mdev);
+ mutex_lock(&occ->occ_lock); + kvfree(occ->buffer); + occ->buffer = NULL; + mutex_unlock(&occ->occ_lock); + device_for_each_child(&pdev->dev, NULL, occ_unregister_child);
ida_simple_remove(&occ_ida, occ->idx);