From: Takashi Iwai Date: Fri, 15 Jan 2021 09:34:28 +0000 (+0100) Subject: ALSA: seq: oss: Fix missing error check in snd_seq_oss_synth_make_info() X-Git-Tag: v4.4.254~24 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d97e020da36331c2149707ff5b8778be4cc535e3;p=thirdparty%2Fkernel%2Fstable.git ALSA: seq: oss: Fix missing error check in snd_seq_oss_synth_make_info() commit 217bfbb8b0bfa24619b11ab75c135fec99b99b20 upstream. snd_seq_oss_synth_make_info() didn't check the error code from snd_seq_oss_midi_make_info(), and this leads to the call of strlcpy() with the uninitialized string as the source, which may lead to the access over the limit. Add the proper error check for avoiding the failure. Reported-by: syzbot+e42504ff21cff05a595f@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/20210115093428.15882-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- diff --git a/sound/core/seq/oss/seq_oss_synth.c b/sound/core/seq/oss/seq_oss_synth.c index df5b984bb33f7..48b3398e9e9d3 100644 --- a/sound/core/seq/oss/seq_oss_synth.c +++ b/sound/core/seq/oss/seq_oss_synth.c @@ -624,7 +624,8 @@ snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_in if (info->is_midi) { struct midi_info minf; - snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf); + if (snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf)) + return -ENXIO; inf->synth_type = SYNTH_TYPE_MIDI; inf->synth_subtype = 0; inf->nr_voices = 16;