From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> [ 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> --- drivers/pci/switch/switchtec.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index 75be4fe225090..0c1faa6c1973a 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -606,21 +606,20 @@ 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 || -- 2.39.2
