From fe0a111c12db5291735e9ca9c1e696b2aba3b583 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 7 Apr 2025 07:51:23 -0600 Subject: [PATCH] io_uring/kbuf: reject zero sized provided buffers commit cf960726eb65e8d0bfecbcce6cf95f47b1ffa6cc upstream. This isn't fixing a real issue, but there's also zero point in going through group and buffer setup, when the buffers are going to be rejected once attempted to get used. Cc: stable@vger.kernel.org Reported-by: syzbot+58928048fd1416f1457c@syzkaller.appspotmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/kbuf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index e1895952066ee..7a8c3a004800e 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -484,6 +484,8 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe p->nbufs = tmp; p->addr = READ_ONCE(sqe->addr); p->len = READ_ONCE(sqe->len); + if (!p->len) + return -EINVAL; if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs, &size)) -- 2.47.2