From: Hao-Yu Yang Date: Mon, 6 Jul 2026 18:33:04 +0000 (+0800) Subject: io_uring: fix dangling iovec after provided-buffer bundle grow failure X-Git-Tag: v7.2-rc3~16^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cd053d788c3f13b3eaf16672d427ee828fda16ed;p=thirdparty%2Fkernel%2Flinux.git io_uring: fix dangling iovec after provided-buffer bundle grow failure When growing a provided-buffer bundle, the old cached iovec is freed before the new buffers have all been validated. If validation fails, the request still points at the freed iovec, which can be freed again during completion cleanup. Fix this by deferring the free of the old cached iovec until validation has succeeded. On failure, free the newly allocated iovec and leave the request pointing at the original one. Fixes: 46800585ae04 ("io_uring/kbuf: validate ring provided buffer addresses with access_ok()") Signed-off-by: Hao-Yu Yang Link: https://patch.msgid.link/20260706183304.919275-1-naup96721@gmail.com Suggested-by: Jens Axboe Signed-off-by: Jens Axboe --- diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 3cd29477fff2..b6b969b55e12 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -287,8 +287,6 @@ static int io_ring_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg, iov = kmalloc_objs(struct iovec, nr_avail); if (unlikely(!iov)) return -ENOMEM; - if (arg->mode & KBUF_MODE_FREE) - kfree(arg->iovs); arg->iovs = iov; nr_iovs = nr_avail; } else if (nr_avail < nr_iovs) { @@ -330,6 +328,9 @@ static int io_ring_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg, buf = io_ring_head_to_buf(br, ++head, bl->mask); } while (--nr_iovs); + if (arg->mode & KBUF_MODE_FREE) + kfree(arg->iovs); + if (head == tail) req->flags |= REQ_F_BL_EMPTY;