mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-30 06:10:56 +00:00
workqueue: Fix NULL pointer dereference
commitcef572ad9b
upstream. When queue_work() is used in irq (not in task context), there is a potential case that trigger NULL pointer dereference. ---------------------------------------------------------------- worker_thread() |-spin_lock_irq() |-process_one_work() |-worker->current_pwq = pwq |-spin_unlock_irq() |-worker->current_func(work) |-spin_lock_irq() |-worker->current_pwq = NULL |-spin_unlock_irq() //interrupt here |-irq_handler |-__queue_work() //assuming that the wq is draining |-is_chained_work(wq) |-current_wq_worker() //Here, 'current' is the interrupted worker! |-current->current_pwq is NULL here! |-schedule() ---------------------------------------------------------------- Avoid it by checking for task context in current_wq_worker(), and if not in task context, we shouldn't use the 'current' to check the condition. Reported-by: Xiaofei Tan <tanxiaofei@huawei.com> Signed-off-by: Li Bin <huawei.libin@huawei.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes:8d03ecfe47
("workqueue: reimplement is_chained_work() using current_wq_worker()") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
2715f6841a
commit
46f15501c5
1 changed files with 2 additions and 1 deletions
|
@ -9,6 +9,7 @@
|
|||
|
||||
#include <linux/workqueue.h>
|
||||
#include <linux/kthread.h>
|
||||
#include <linux/preempt.h>
|
||||
|
||||
struct worker_pool;
|
||||
|
||||
|
@ -59,7 +60,7 @@ struct worker {
|
|||
*/
|
||||
static inline struct worker *current_wq_worker(void)
|
||||
{
|
||||
if (current->flags & PF_WQ_WORKER)
|
||||
if (in_task() && (current->flags & PF_WQ_WORKER))
|
||||
return kthread_data(current);
|
||||
return NULL;
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue