Re: [PATCH 08/32] aio: replace kiocb_set_cancel_fn with a cancel_kiocb file operation
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: 2018-05-20 05:27:59
Also in:
linux-api, linux-fsdevel, lkml
On Tue, May 15, 2018 at 09:48:09PM +0200, Christoph Hellwig wrote:
case -EIOCBQUEUED:
+ if (req->ki_filp->f_op->cancel_kiocb) {
+ struct aio_kiocb *iocb =
+ container_of(req, struct aio_kiocb, rw);
+ struct kioctx *ctx = iocb->ki_ctx;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->ctx_lock, flags);
+ list_add_tail(&iocb->ki_list, &ctx->active_reqs);Use after free - that list insertion used to be done by drivers and doing so before any ->ki_complete() calls might've happened used to be their responsibility. Now you've taken that to the point after ->read_iter() (or ->write_iter()) return, so there's no way in hell to guarantee it's not been completed (and freed) by that point. Incidentally, none of the callers gives a damn about the difference between 0 and -EIOCBQUEUED now, so aio_rw_ret() might as well had been made void... -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: <a href=mailto:"aart@kvack.org">aart@kvack.org</a>