From: Jens Axboe <axboe@kernel.dk>
To: io-uring <io-uring@vger.kernel.org>
Subject: [PATCH] io_uring/kbuf: reject zero sized provided buffers
Date: Mon, 7 Apr 2025 07:53:15 -0600 [thread overview]
Message-ID: <d04e49ee-13c0-4581-b056-e6b1ea7c31d2@kernel.dk> (raw)
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 <axboe@kernel.dk>
---
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index 098109259671..953d5e742569 100644
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -504,6 +504,8 @@ 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))
--
Jens Axboe
reply other threads:[~2025-04-07 13:53 UTC|newest]
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