Messages in this thread | | | Subject | Re: [PATCH] workqueue: Fix NULL pointer dereference | From | Li Bin <> | Date | Fri, 27 Oct 2017 13:24:49 +0800 |
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Hi, Jiangshan
on 2017/10/26 23:55, Lai Jiangshan wrote: > On Tue, Oct 24, 2017 at 9:18 AM, Li Bin <huawei.libin@huawei.com> wrote:
> > I remember that softirq can be invoked when irq_eixt(), > and in this case the current->current_pwq is also NULL > if __queue_work() is called in the soft irq. > > So in_task() might be better than !in_irq() for the fix? >
Good catch, I will fix it and resend the patch.
Thanks, Li Bin
>> |-schedule() >> ---------------------------------------------------------------- >> >> Avoid it by checking for irq context in current_wq_worker(), and >> if in irq 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> >> --- >> kernel/workqueue_internal.h | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h >> index 8635417..d81cb9b 100644 >> --- a/kernel/workqueue_internal.h >> +++ b/kernel/workqueue_internal.h >> @@ -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_irq() && (current->flags & PF_WQ_WORKER)) >> return kthread_data(current); >> return NULL; >> } >> -- >> 1.7.12.4 >> > > . >
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