linux-kernel - [PATCH AUTOSEL 5.7 07/25] io_uring: always allow drain/link/hardlink/async sqe flags

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200727232345.717432-7-sashal@kernel.org>
Date:   Mon, 27 Jul 2020 19:23:27 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Daniele Albano <d.albano@...il.com>, Jens Axboe <axboe@...nel.dk>,
        Sasha Levin <sashal@...nel.org>, linux-fsdevel@...r.kernel.org,
        io-uring@...r.kernel.org
Subject: [PATCH AUTOSEL 5.7 07/25] io_uring: always allow drain/link/hardlink/async sqe flags

From: Daniele Albano <d.albano@...il.com>

[ Upstream commit 61710e437f2807e26a3402543bdbb7217a9c8620 ]

We currently filter these for timeout_remove/async_cancel/files_update,
but we only should be filtering for fixed file and buffer select. This
also causes a second read of sqe->flags, which isn't needed.

Just check req->flags for the relevant bits. This then allows these
commands to be used in links, for example, like everything else.

Signed-off-by: Daniele Albano <d.albano@...il.com>
Signed-off-by: Jens Axboe <axboe@...nel.dk>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/io_uring.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 51be3a20ade17..12ab983474dff 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4803,7 +4803,9 @@ static int io_timeout_remove_prep(struct io_kiocb *req,
 {
 	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
-	if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->len)
+	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+		return -EINVAL;
+	if (sqe->ioprio || sqe->buf_index || sqe->len)
 		return -EINVAL;
 
 	req->timeout.addr = READ_ONCE(sqe->addr);
@@ -5009,8 +5011,9 @@ static int io_async_cancel_prep(struct io_kiocb *req,
 {
 	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
-	if (sqe->flags || sqe->ioprio || sqe->off || sqe->len ||
-	    sqe->cancel_flags)
+	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+		return -EINVAL;
+	if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags)
 		return -EINVAL;
 
 	req->cancel.addr = READ_ONCE(sqe->addr);
@@ -5028,7 +5031,9 @@ static int io_async_cancel(struct io_kiocb *req)
 static int io_files_update_prep(struct io_kiocb *req,
 				const struct io_uring_sqe *sqe)
 {
-	if (sqe->flags || sqe->ioprio || sqe->rw_flags)
+	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+		return -EINVAL;
+	if (sqe->ioprio || sqe->rw_flags)
 		return -EINVAL;
 
 	req->files_update.offset = READ_ONCE(sqe->off);
-- 
2.25.1