diff options
Diffstat (limited to 'drivers/char/misc.c')
| -rw-r--r-- | drivers/char/misc.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 558302a64dd9..726516fb0a3b 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -132,7 +132,8 @@ static int misc_open(struct inode *inode, struct file *file) break; } - if (!new_fops) { + /* Only request module for fixed minor code */ + if (!new_fops && minor < MISC_DYNAMIC_MINOR) { mutex_unlock(&misc_mtx); request_module("char-major-%d-%d", MISC_MAJOR, minor); mutex_lock(&misc_mtx); @@ -144,10 +145,11 @@ static int misc_open(struct inode *inode, struct file *file) new_fops = fops_get(iter->fops); break; } - if (!new_fops) - goto fail; } + if (!new_fops) + goto fail; + /* * Place the miscdevice in the file's * private_data so it can be used by the @@ -210,6 +212,12 @@ int misc_register(struct miscdevice *misc) int err = 0; bool is_dynamic = (misc->minor == MISC_DYNAMIC_MINOR); + if (misc->minor > MISC_DYNAMIC_MINOR) { + pr_err("Invalid fixed minor %d for miscdevice '%s'\n", + misc->minor, misc->name); + return -EINVAL; + } + INIT_LIST_HEAD(&misc->list); mutex_lock(&misc_mtx); @@ -275,13 +283,12 @@ EXPORT_SYMBOL(misc_register); void misc_deregister(struct miscdevice *misc) { - if (WARN_ON(list_empty(&misc->list))) - return; - mutex_lock(&misc_mtx); - list_del(&misc->list); + list_del_init(&misc->list); device_destroy(&misc_class, MKDEV(MISC_MAJOR, misc->minor)); misc_minor_free(misc->minor); + if (misc->minor > MISC_DYNAMIC_MINOR) + misc->minor = MISC_DYNAMIC_MINOR; mutex_unlock(&misc_mtx); } EXPORT_SYMBOL(misc_deregister); |