[ogabbay:habanalabs-next 47/47] drivers/misc/habanalabs/common/habanalabs_ioctl.c:135 events_info() warn: maybe return -EFAULT instead of the bytes remaining?

From: Dan Carpenter
Date: Wed May 11 2022 - 05:44:15 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/ogabbay/linux.git habanalabs-next
head: 20c59ac5d71e766235e74f353b74e60facd733c8
commit: 20c59ac5d71e766235e74f353b74e60facd733c8 [47/47] habanalabs: add support for notification via eventfd
config: x86_64-randconfig-m001-20220509 (https://download.01.org/0day-ci/archive/20220510/202205100736.Y0Vi5Fcf-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.2.0-20) 11.2.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
drivers/misc/habanalabs/common/habanalabs_ioctl.c:135 events_info() warn: maybe return -EFAULT instead of the bytes remaining?

vim +135 drivers/misc/habanalabs/common/habanalabs_ioctl.c

20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 119 static int events_info(struct hl_fpriv *hpriv, struct hl_info_args *args)
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 120 {
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 121 int rc;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 122 u32 max_size = args->return_size;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 123 u64 events_mask;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 124 void __user *out = (void __user *) (uintptr_t) args->return_pointer;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 125
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 126 if ((max_size < sizeof(u64)) || (!out))
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 127 return -EINVAL;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 128
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 129 mutex_lock(&hpriv->notifier_event.lock);
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 130 events_mask = hpriv->notifier_event.events_mask;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 131 hpriv->notifier_event.events_mask = 0;
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 132 mutex_unlock(&hpriv->notifier_event.lock);
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 133
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 134 rc = copy_to_user(out, &events_mask, sizeof(u64));
20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 @135 return rc;

copy_to_user() returns the number of bytes remaining (positive). This
should be:

if (copy_to_user(out, &events_mask, sizeof(u64)))
return -EFAULT;

return 0;

20c59ac5d71e76 drivers/misc/habanalabs/common/habanalabs_ioctl.c Tal Cohen 2022-04-28 136 }

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