Messages in this thread Patch in this message | | | From | Shaohua Li <> | Subject | [PATCH] kthread: move the cgroup info initialization early | Date | Tue, 7 Nov 2017 09:57:03 -0800 |
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kthread() could bail out early before we initialize blkcg_css (if the kthread is killed very soon), which confuses free_kthread_struct. Move the blkcg_css initialization early.
Reported-by: syzbot <syzkaller@googlegroups.com> Fix: 05e3db9(kthread: add a mechanism to store cgroup info) Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Shaohua Li <shli@fb.com> --- kernel/kthread.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/kthread.c b/kernel/kthread.c index f87cd8b4..cf5c113 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -205,6 +205,10 @@ static int kthread(void *_create) int ret; self = kmalloc(sizeof(*self), GFP_KERNEL); +#ifdef CONFIG_BLK_CGROUP + if (self) + self->blkcg_css = NULL; +#endif set_kthread_struct(self); /* If user was SIGKILLed, I release the structure. */ @@ -224,9 +228,6 @@ static int kthread(void *_create) self->data = data; init_completion(&self->exited); init_completion(&self->parked); -#ifdef CONFIG_BLK_CGROUP - self->blkcg_css = NULL; -#endif current->vfork_done = &self->exited; /* OK, tell user we're spawned, wait for stop or wakeup */ -- 2.9.5
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