linux-kernel - [PATCH 4.4 01/76] hidraw: Return EPOLLOUT from hidraw

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: <20200122092751.885292472@linuxfoundation.org>
Date:   Wed, 22 Jan 2020 10:28:17 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Fabian Henneke <fabian.henneke@...il.com>,
        Jiri Kosina <jkosina@...e.cz>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.4 01/76] hidraw: Return EPOLLOUT from hidraw_poll

From: Fabian Henneke <fabian.henneke@...il.com>

[ Upstream commit 378b80370aa1fe50f9c48a3ac8af3e416e73b89f ]

Always return EPOLLOUT from hidraw_poll when a device is connected.
This is safe since writes are always possible (but will always block).

hidraw does not support non-blocking writes and instead always calls
blocking backend functions on write requests. Hence, so far, a call to
poll never returned EPOLLOUT, which confuses tools like socat.

Signed-off-by: Fabian Henneke <fabian.henneke@...il.com>
In-reply-to: <CA+hv5qkyis03CgYTWeWX9cr0my-d2Oe+aZo+mjmWRXgjrGqyrw@...l.gmail.com>
Signed-off-by: Jiri Kosina <jkosina@...e.cz>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/hid/hidraw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 627a24d3ea7c..27d2f5a48a11 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -265,7 +265,7 @@ static unsigned int hidraw_poll(struct file *file, poll_table *wait)
 
 	poll_wait(file, &list->hidraw->wait, wait);
 	if (list->head != list->tail)
-		return POLLIN | POLLRDNORM;
+		return POLLIN | POLLRDNORM | POLLOUT;
 	if (!list->hidraw->exist)
 		return POLLERR | POLLHUP;
 	return 0;
-- 
2.20.1