io_uring: reference ->nsproxy for file table commands

If we don't get and assign the namespace for the async work, then certain
paths just don't work properly (like /dev/stdin, /proc/mounts, etc).
Anything that references the current namespace of the given task should
be assigned for async work on behalf of that task.

Cc: stable@vger.kernel.org # v5.5+
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-09-18 20:13:06 -06:00
parent 0f2122045b
commit 9b82849215
3 changed files with 8 additions and 0 deletions

View file

@ -60,6 +60,7 @@ struct io_worker {
const struct cred *cur_creds;
const struct cred *saved_creds;
struct files_struct *restore_files;
struct nsproxy *restore_nsproxy;
struct fs_struct *restore_fs;
};
@ -153,6 +154,7 @@ static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker)
task_lock(current);
current->files = worker->restore_files;
current->nsproxy = worker->restore_nsproxy;
task_unlock(current);
}
@ -318,6 +320,7 @@ static void io_worker_start(struct io_wqe *wqe, struct io_worker *worker)
worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
worker->restore_files = current->files;
worker->restore_nsproxy = current->nsproxy;
worker->restore_fs = current->fs;
io_wqe_inc_running(wqe, worker);
}
@ -454,6 +457,7 @@ static void io_impersonate_work(struct io_worker *worker,
if (work->files && current->files != work->files) {
task_lock(current);
current->files = work->files;
current->nsproxy = work->nsproxy;
task_unlock(current);
}
if (work->fs && current->fs != work->fs)

View file

@ -88,6 +88,7 @@ struct io_wq_work {
struct files_struct *files;
struct mm_struct *mm;
const struct cred *creds;
struct nsproxy *nsproxy;
struct fs_struct *fs;
unsigned long fsize;
unsigned flags;

View file

@ -5678,6 +5678,7 @@ static void io_req_drop_files(struct io_kiocb *req)
spin_unlock_irqrestore(&ctx->inflight_lock, flags);
req->flags &= ~REQ_F_INFLIGHT;
put_files_struct(req->work.files);
put_nsproxy(req->work.nsproxy);
req->work.files = NULL;
}
@ -6086,6 +6087,8 @@ static int io_grab_files(struct io_kiocb *req)
return 0;
req->work.files = get_files_struct(current);
get_nsproxy(current->nsproxy);
req->work.nsproxy = current->nsproxy;
req->flags |= REQ_F_INFLIGHT;
spin_lock_irq(&ctx->inflight_lock);