* Fwd: [PATCH] fs/io_uring.c: Fix uninitialized variable is referenced in io_submit_sqe
[not found] <20200813065644.GA91891@ubuntu>
@ 2020-08-13 15:11 ` Jens Axboe
2020-08-14 16:42 ` Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Jens Axboe @ 2020-08-13 15:11 UTC (permalink / raw)
To: stable
Hi,
Can you queue this up for 5.4 as well? Thanks!
-------- Forwarded Message --------
Subject: [PATCH] fs/io_uring.c: Fix uninitialized variable is referenced in io_submit_sqe
Date: Wed, 12 Aug 2020 23:56:44 -0700
From: Liu Yong <pkfxxxing@gmail.com>
To: Jens Axboe <axboe@kernel.dk>
CC: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
the commit <a4d61e66ee4a> ("<io_uring: prevent re-read of sqe->opcode>")
caused another vulnerability. After io_get_req(), the sqe_submit struct
in req is not initialized, but the following code defaults that
req->submit.opcode is available.
Signed-off-by: Liu Yong <pkfxxxing@gmail.com>
---
fs/io_uring.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index be3d595a607f..c1aaee061dae 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2559,6 +2559,7 @@ static void io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s,
goto err;
}
+ memcpy(&req->submit, s, sizeof(*s));
ret = io_req_set_file(ctx, s, state, req);
if (unlikely(ret)) {
err_req:
--
2.17.1
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