diff options
| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-03-06 16:21:13 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-17 13:32:59 +0900 |
| commit | b7ddc981d7b9e2fbfb33cb7cc47603d6e5d93bc9 (patch) | |
| tree | 036cfca17f24b8bc912dc1a576a762c7b8978491 /drivers/usb/gadget/legacy | |
| parent | 43938613c6fd2e58a0be212c832e1878bedefe5a (diff) | |
drivers, usb: convert dev_data.count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget/legacy')
| -rw-r--r-- | drivers/usb/gadget/legacy/inode.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index a2c916869293..db34b4dee0d9 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -27,6 +27,7 @@ #include <linux/mmu_context.h> #include <linux/aio.h> #include <linux/uio.h> +#include <linux/refcount.h> #include <linux/device.h> #include <linux/moduleparam.h> @@ -114,7 +115,7 @@ enum ep0_state { struct dev_data { spinlock_t lock; - atomic_t count; + refcount_t count; enum ep0_state state; /* P: lock */ struct usb_gadgetfs_event event [N_EVENT]; unsigned ev_next; @@ -150,12 +151,12 @@ struct dev_data { static inline void get_dev (struct dev_data *data) { - atomic_inc (&data->count); + refcount_inc (&data->count); } static void put_dev (struct dev_data *data) { - if (likely (!atomic_dec_and_test (&data->count))) + if (likely (!refcount_dec_and_test (&data->count))) return; /* needs no more cleanup */ BUG_ON (waitqueue_active (&data->wait)); @@ -170,7 +171,7 @@ static struct dev_data *dev_new (void) if (!dev) return NULL; dev->state = STATE_DEV_DISABLED; - atomic_set (&dev->count, 1); + refcount_set (&dev->count, 1); spin_lock_init (&dev->lock); INIT_LIST_HEAD (&dev->epfiles); init_waitqueue_head (&dev->wait); |