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authorTakashi Iwai <tiwai@suse.de>2021-05-10 17:06:59 +0200
committerTakashi Iwai <tiwai@suse.de>2021-05-10 17:08:38 +0200
commite84749a78dc82bc545f12ce009e3dbcc2c5a8a91 (patch)
treede7946aafb61ac751a531065920c599003027f27 /sound/usb/midi.c
parentc1b55029493879f5bd585ff79f326e71f0bc05e3 (diff)
ALSA: usb-audio: Validate MS endpoint descriptors
snd_usbmidi_get_ms_info() may access beyond the border when a malformed descriptor is passed. This patch adds the sanity checks of the given MS endpoint descriptors, and skips invalid ones. Reported-by: syzbot+6bb23a5d5548b93c94aa@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210510150659.17710-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/midi.c')
-rw-r--r--sound/usb/midi.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index a10ac75969a8..649eb8d1ab7d 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -1956,8 +1956,12 @@ static int snd_usbmidi_get_ms_info(struct snd_usb_midi *umidi,
ms_ep = find_usb_ms_endpoint_descriptor(hostep);
if (!ms_ep)
continue;
+ if (ms_ep->bLength <= sizeof(*ms_ep))
+ continue;
if (ms_ep->bNumEmbMIDIJack > 0x10)
continue;
+ if (ms_ep->bLength < sizeof(*ms_ep) + ms_ep->bNumEmbMIDIJack)
+ continue;
if (usb_endpoint_dir_out(ep)) {
if (endpoints[epidx].out_ep) {
if (++epidx >= MIDI_MAX_ENDPOINTS) {