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authorBernat, Yehezkel <yehezkel.bernat@intel.com>2017-08-15 07:19:20 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-28 16:21:32 +0200
commite545f0d8a54a9594fe604d67d80ca6fddf72ca59 (patch)
treefdb0440cc8fdf2788924a807d2fc5ab444a320c1 /drivers/thunderbolt
parentthunderbolt: Make key root-only accessible (diff)
downloadlinux-e545f0d8a54a9594fe604d67d80ca6fddf72ca59.tar.xz
linux-e545f0d8a54a9594fe604d67d80ca6fddf72ca59.zip
thunderbolt: Allow clearing the key
If secure authentication of a devices fails, either because the device already has another key uploaded, or there is some other error sending challenge to the device, and the user only wants to approve the device just once (without a new key being uploaded to the device) the current implementation does not allow this because the key cannot be cleared once set even if we allow it to be changed. Make this scenario possible and allow clearing the key by writing empty string to the key sysfs file. Signed-off-by: Yehezkel Bernat <yehezkel.bernat@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/thunderbolt')
-rw-r--r--drivers/thunderbolt/switch.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 8510abcee5d2..53f40c57df59 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -807,8 +807,11 @@ static ssize_t key_store(struct device *dev, struct device_attribute *attr,
struct tb_switch *sw = tb_to_switch(dev);
u8 key[TB_SWITCH_KEY_SIZE];
ssize_t ret = count;
+ bool clear = false;
- if (hex2bin(key, buf, sizeof(key)))
+ if (!strcmp(buf, "\n"))
+ clear = true;
+ else if (hex2bin(key, buf, sizeof(key)))
return -EINVAL;
if (mutex_lock_interruptible(&switch_lock))
@@ -818,9 +821,13 @@ static ssize_t key_store(struct device *dev, struct device_attribute *attr,
ret = -EBUSY;
} else {
kfree(sw->key);
- sw->key = kmemdup(key, sizeof(key), GFP_KERNEL);
- if (!sw->key)
- ret = -ENOMEM;
+ if (clear) {
+ sw->key = NULL;
+ } else {
+ sw->key = kmemdup(key, sizeof(key), GFP_KERNEL);
+ if (!sw->key)
+ ret = -ENOMEM;
+ }
}
mutex_unlock(&switch_lock);