From: Jens Axboe axboe@kernel.dk
stable inclusion from linux-4.19.161 commit 49d04a6948825b309411d13e97109857e4f76de6
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[ Upstream commit 8d4c3e76e3be11a64df95ddee52e99092d42fc19 ]
If this is attempted by a kthread, then return -EOPNOTSUPP as we don't currently support that. Once we can get task_pid_ptr() doing the right thing, then this can go away again.
Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/proc/self.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/fs/proc/self.c b/fs/proc/self.c index cc6d4253399d..7922edf70ce1 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -16,6 +16,13 @@ static const char *proc_self_get_link(struct dentry *dentry, pid_t tgid = task_tgid_nr_ns(current, ns); char *name;
+ /* + * Not currently supported. Once we can inherit all of struct pid, + * we can allow this. + */ + if (current->flags & PF_KTHREAD) + return ERR_PTR(-EOPNOTSUPP); + if (!tgid) return ERR_PTR(-ENOENT); /* max length of unsigned int in decimal + NULL term */