From: Takashi Iwai tiwai@suse.de
[ 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 ricardo@marliere.net Link: https://lore.kernel.org/r/20230922005152.163640-1-ricardo@marliere.net Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sean Young sean@mess.org Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Sasha Levin sashal@kernel.org --- 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 72e4bb0fb71ec..4e7c3d889d5ce 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) {