io_uring: fix files cancellation

io_uring_cancel_files()'s task check condition mistakenly got flipped.

1. There can't be a request in the inflight list without
IO_WQ_WORK_FILES, kill this check to keep the whole condition simpler.
2. Also, don't call the function for files==NULL to not do such a check,
all that staff is already handled well by its counter part,
__io_uring_cancel_task_requests().

With that just flip the task check.

Also, it iowq-cancels all request of current task there, don't forget to
set right ->files into struct io_task_cancel.

Fixes: c1973b38bf639 ("io_uring: cancel only requests of current task")
Reported-by: syzbot+c0d52d0b3c0c3ffb9525@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index e66888d..f47de27 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8688,15 +8688,14 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
                                  struct files_struct *files)
 {
        while (!list_empty_careful(&ctx->inflight_list)) {
-               struct io_task_cancel cancel = { .task = task, .files = NULL, };
+               struct io_task_cancel cancel = { .task = task, .files = files };
                struct io_kiocb *req;
                DEFINE_WAIT(wait);
                bool found = false;
 
                spin_lock_irq(&ctx->inflight_lock);
                list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {
-                       if (req->task == task &&
-                           (req->work.flags & IO_WQ_WORK_FILES) &&
+                       if (req->task != task ||
                            req->work.identity->files != files)
                                continue;
                        found = true;
@@ -8768,10 +8767,11 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 
        io_cancel_defer_files(ctx, task, files);
        io_cqring_overflow_flush(ctx, true, task, files);
-       io_uring_cancel_files(ctx, task, files);
 
        if (!files)
                __io_uring_cancel_task_requests(ctx, task);
+       else
+               io_uring_cancel_files(ctx, task, files);
 
        if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
                atomic_dec(&task->io_uring->in_idle);