Am Dienstag, den 23.07.2019, 05:48 -0700 schrieb syzbot: > Hello, > > syzbot found the following crash on: > > HEAD commit: 6a3599ce usb-fuzzer: main usb gadget fuzzer driver > git tree: https://github.com/google/kasan.git usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=11b13e78600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=700ca426ab83faae > dashboard link: https://syzkaller.appspot.com/bug?extid=ef5de9c4f99c4edb4e49 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15482210600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1139b07c600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+ef5de9c4f99c4edb4...@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: use-after-free in usbhid_power+0xca/0xe0 > /drivers/hid/usbhid/hid-core.c:1234 > Read of size 8 at addr ffff8881ce8a4008 by task syz-executor373/1763
#syz test: https://github.com/google/kasan.git usb-fuzzer >From a3455c4527bdfe86536856ea96288b7dcc36590b Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneu...@suse.com> Date: Wed, 24 Jul 2019 22:49:57 +0200 Subject: [PATCH] usbhid: test for disconnected state in raw opening If the device has been disconnected, we should not proceed to use runtime PM on it. Reported-by: syzbot+ef5de9c4f99c4edb4...@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum <oneu...@suse.de> --- drivers/hid/usbhid/hid-core.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index c7bc9db5b192..98b996ecf4d3 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -1229,6 +1229,17 @@ static int usbhid_power(struct hid_device *hid, int lvl) struct usbhid_device *usbhid = hid->driver_data; int r = 0; + spin_lock_irq(&usbhid->lock); + if (test_bit(HID_DISCONNECTED, &usbhid->iofl)) { + r = -ENODEV; + spin_unlock_irq(&usbhid->lock); + goto bail_out; + } else { + /* protect against disconnect */ + usb_get_dev(interface_to_usbdev(usbhid->intf)); + spin_unlock_irq(&usbhid->lock); + } + switch (lvl) { case PM_HINT_FULLON: r = usb_autopm_get_interface(usbhid->intf); @@ -1238,7 +1249,9 @@ static int usbhid_power(struct hid_device *hid, int lvl) usb_autopm_put_interface(usbhid->intf); break; } + usb_put_dev(interface_to_usbdev(usbhid->intf)); +bail_out: return r; } -- 2.16.4
