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authorJiri Kosina <jkosina@suse.cz>2009-10-12 13:25:56 +0400
committerJiri Kosina <jkosina@suse.cz>2009-10-12 13:25:56 +0400
commitb0e14951ee0f6c29abc64b92ec7075a159ede37c (patch)
treeaa10393c1f54a2342fbd4d3624d6e68de376cd8d
parentff9b00a226ccea66e6ce70e9083c42f5b6001f73 (diff)
downloadlinux-b0e14951ee0f6c29abc64b92ec7075a159ede37c.tar.xz
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>
-rw-r--r--drivers/hid/hidraw.c5
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,
char *report;
DECLARE_WAITQUEUE(wait, current);
- while (ret == 0) {
-
- mutex_lock(&list->read_mutex);
+ mutex_lock(&list->read_mutex);
+ while (ret == 0) {
if (list->head == list->tail) {
add_wait_queue(&list->hidraw->wait, &wait);
set_current_state(TASK_INTERRUPTIBLE);