HID: hidraw, fix a NULL pointer dereference in hidraw_ioctl

BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
IP: [<ffffffffa02c66b4>] hidraw_ioctl+0xfc/0x32c [hid]
[...]

This is reproducible by disconnecting the device while userspace does
ioctl in a loop and doesn't check return values in order to exit the
loop.

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Cc: stable@kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Antonio Ospite 2010-10-05 17:20:16 +02:00 committed by Jiri Kosina
parent a850ea3037
commit d20d5ffab9

View File

@ -244,6 +244,10 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
mutex_lock(&minors_lock);
dev = hidraw_table[minor];
if (!dev) {
ret = -ENODEV;
goto out;
}
switch (cmd) {
case HIDIOCGRDESCSIZE:
@ -317,6 +321,7 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
ret = -ENOTTY;
}
out:
mutex_unlock(&minors_lock);
return ret;
}