From: Takashi Iwai tiwai@suse.de
commit 167beb1756791e0806365a3f86a0da10d7a327ee upstream.
A check of the return value from get_cur_mix_raw() is missing at the resolution test code in get_min_max_with_quirks(), which may leave the variable untouched, leading to a random uninitialized value, as detected by syzkaller fuzzer.
Add the missing return error check for fixing that.
Reported-and-tested-by: syzbot+abe1ab7afc62c6bb6377@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191109181658.30368-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/usb/mixer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1045,7 +1045,8 @@ static int get_min_max_with_quirks(struc if (cval->min + cval->res < cval->max) { int last_valid_res = cval->res; int saved, test, check; - get_cur_mix_raw(cval, minchn, &saved); + if (get_cur_mix_raw(cval, minchn, &saved) < 0) + goto no_res_check; for (;;) { test = saved; if (test < cval->max) @@ -1065,6 +1066,7 @@ static int get_min_max_with_quirks(struc snd_usb_set_cur_mix_value(cval, minchn, 0, saved); }
+no_res_check: cval->initialized = 1; }