From 2a493a34bd6e496c55fabedd82b957193ace178f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 22 Sep 2023 14:38:07 +0200 Subject: [PATCH] media: imon: fix access to invalid resource for the second interface [ Upstream commit a1766a4fd83befa0b34d932d532e7ebb7fab1fa7 ] imon driver probes two USB interfaces, and at the probe of the second interface, the driver assumes blindly that the first interface got bound with the same imon driver. It's usually true, but it's still possible that the first interface is bound with another driver via a malformed descriptor. Then it may lead to a memory corruption, as spotted by syzkaller; imon driver accesses the data from drvdata as struct imon_context object although it's a completely different one that was assigned by another driver. This patch adds a sanity check -- whether the first interface is really bound with the imon driver or not -- for avoiding the problem above at the probe time. Reported-by: syzbot+59875ffef5cb9c9b29e9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000a838aa0603cc74d6@google.com/ Tested-by: Ricardo B. Marliere Link: https://lore.kernel.org/r/20230922005152.163640-1-ricardo@marliere.net Signed-off-by: Takashi Iwai Signed-off-by: Sean Young Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/rc/imon.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c index 74546f7..5719dda 100644 --- a/drivers/media/rc/imon.c +++ b/drivers/media/rc/imon.c @@ -2427,6 +2427,12 @@ static int imon_probe(struct usb_interface *interface, goto fail; } + if (first_if->dev.driver != interface->dev.driver) { + dev_err(&interface->dev, "inconsistent driver matching\n"); + ret = -EINVAL; + goto fail; + } + if (ifnum == 0) { ictx = imon_init_intf0(interface, id); if (!ictx) { -- 2.7.4