diff options
author | Jiri Kosina <jkosina@suse.cz> | 2009-10-12 05:25:56 -0400 |
---|---|---|
committer | Jiri Kosina <jkosina@suse.cz> | 2009-10-12 05:25:56 -0400 |
commit | b0e14951ee0f6c29abc64b92ec7075a159ede37c (patch) | |
tree | aa10393c1f54a2342fbd4d3624d6e68de376cd8d /drivers/hid | |
parent | ff9b00a226ccea66e6ce70e9083c42f5b6001f73 (diff) |
HID: fix possible deadlock in hidraw_read
If the loop in hidraw_read() loops more than once, then we might
end up trying to acquire already locked mutex, casuing a deadlock.
Reported-by: iceberg <iceberg@ispras.ru>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
-rw-r--r-- | drivers/hid/hidraw.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 0c6639ea03dd..b079a9c59958 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c | |||
@@ -47,10 +47,9 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, | |||
47 | char *report; | 47 | char *report; |
48 | DECLARE_WAITQUEUE(wait, current); | 48 | DECLARE_WAITQUEUE(wait, current); |
49 | 49 | ||
50 | while (ret == 0) { | 50 | mutex_lock(&list->read_mutex); |
51 | |||
52 | mutex_lock(&list->read_mutex); | ||
53 | 51 | ||
52 | while (ret == 0) { | ||
54 | if (list->head == list->tail) { | 53 | if (list->head == list->tail) { |
55 | add_wait_queue(&list->hidraw->wait, &wait); | 54 | add_wait_queue(&list->hidraw->wait, &wait); |
56 | set_current_state(TASK_INTERRUPTIBLE); | 55 | set_current_state(TASK_INTERRUPTIBLE); |