From:   Pietro Borrello <borrello@diag.uniroma1.it>
Date:   Sun, 12 Feb 2023 19:00:00 +0000
Subject: [PATCH v4 2/5] HID: bigben_worker() remove unneeded check on
 report_field
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Message-Id: <20230125-hid-unregister-leds-v4-2-7860c5763c38@diag.uniroma1.it>
References: <20230125-hid-unregister-leds-v4-0-7860c5763c38@diag.uniroma1.it>
In-Reply-To: <20230125-hid-unregister-leds-v4-0-7860c5763c38@diag.uniroma1.it>
To:     Jiri Kosina <jikos@kernel.org>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Hanno Zulla <kontakt@hanno.de>, Hanno Zulla <abos@hanno.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Cristiano Giuffrida <c.giuffrida@vu.nl>,
        "Bos, H.J." <h.j.bos@vu.nl>, Jakob Koschel <jkl820.git@gmail.com>,
        Jiri Kosina <jkosina@suse.cz>,
        Roderick Colenbrander <roderick@gaikai.com>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        Pietro Borrello <borrello@diag.uniroma1.it>
Precedence: bulk

bigben_worker() checks report_field to be non-NULL.
The check has been added in commit
918aa1ef104d ("HID: bigbenff: prevent null pointer dereference")
to prevent a NULL pointer crash.
However, the true root cause was a missing check for output
reports, patched in commit
c7bf714f8755 ("HID: check empty report_list in bigben_probe()"),
where the type-confused report list_entry was overlapping with
a NULL pointer, which was then causing the crash.

Fixes: 918aa1ef104d ("HID: bigbenff: prevent null pointer dereference")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
---
 drivers/hid/hid-bigbenff.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hid-bigbenff.c b/drivers/hid/hid-bigbenff.c
index ed3d2d7bc1dd..b98c5f31c184 100644
--- a/drivers/hid/hid-bigbenff.c
+++ b/drivers/hid/hid-bigbenff.c
@@ -197,7 +197,7 @@ static void bigben_worker(struct work_struct *work)
 	u32 len;
 	unsigned long flags;
 
-	if (bigben->removed || !report_field)
+	if (bigben->removed)
 		return;
 
 	buf = hid_alloc_report_buf(bigben->report, GFP_KERNEL);

-- 
2.25.1