From 61cda68902db0f0e926e17b436c5c88ee578df63 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 13 Nov 2020 16:47:52 -0700 Subject: [PATCH] proc: don't allow async path resolution of /proc/self components [ 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 Signed-off-by: Sasha Levin --- fs/proc/self.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/proc/self.c b/fs/proc/self.c index c8bbc1c84a39..f6e2e3fb8a22 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -26,6 +26,13 @@ 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); /* 11 for max length of signed int in decimal + NULL term */