6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Takashi Iwai tiwai@suse.de
[ Upstream commit 56f1f30e6795b890463d9b20b11e576adf5a2f77 ]
The conversion function from MIDI 1.0 to UMP packet contains an internal buffer to keep the incoming MIDI bytes, and its size is 4, as it was supposed to be the max size for a MIDI1 UMP packet data. However, the implementation overlooked that SysEx is handled in a different format, and it can be up to 6 bytes, as found in do_convert_to_ump(). It leads eventually to a buffer overflow, and may corrupt the memory when a longer SysEx message is received.
The fix is simply to extend the buffer size to 6 to fit with the SysEx UMP message.
Fixes: 0b5288f5fe63 ("ALSA: ump: Add legacy raw MIDI support") Reported-by: Argusee vr@darknavy.com Link: https://patch.msgid.link/20250429124845.25128-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- include/sound/ump_convert.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/sound/ump_convert.h b/include/sound/ump_convert.h index d099ae27f8491..682499b871eac 100644 --- a/include/sound/ump_convert.h +++ b/include/sound/ump_convert.h @@ -19,7 +19,7 @@ struct ump_cvt_to_ump_bank { /* context for converting from MIDI1 byte stream to UMP packet */ struct ump_cvt_to_ump { /* MIDI1 intermediate buffer */ - unsigned char buf[4]; + unsigned char buf[6]; /* up to 6 bytes for SysEx */ int len; int cmd_bytes;