4.19-stable review patch. If anyone has any objections, please let me know.
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From: Camila Alvarez cam.alvarez.i@gmail.com
[ Upstream commit a6e9c391d45b5865b61e569146304cff72821a5d ]
report_fixup for the Cougar 500k Gaming Keyboard was not verifying that the report descriptor size was correct before accessing it
Reported-by: syzbot+24c0361074799d02c452@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=24c0361074799d02c452 Signed-off-by: Camila Alvarez cam.alvarez.i@gmail.com Reviewed-by: Silvan Jegen s.jegen@gmail.com Signed-off-by: Jiri Kosina jkosina@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hid/hid-cougar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hid/hid-cougar.c b/drivers/hid/hid-cougar.c index ad2e87de7dc5..d58a108a96c0 100644 --- a/drivers/hid/hid-cougar.c +++ b/drivers/hid/hid-cougar.c @@ -104,7 +104,7 @@ static void cougar_fix_g6_mapping(struct hid_device *hdev) static __u8 *cougar_report_fixup(struct hid_device *hdev, __u8 *rdesc, unsigned int *rsize) { - if (rdesc[2] == 0x09 && rdesc[3] == 0x02 && + if (*rsize >= 117 && rdesc[2] == 0x09 && rdesc[3] == 0x02 && (rdesc[115] | rdesc[116] << 8) >= HID_MAX_USAGES) { hid_info(hdev, "usage count exceeds max: fixing up report descriptor\n");