ALSA: firewire-lib: fix check for the size of isochronous packet payload

BugLink: https://bugs.launchpad.net/bugs/1931896
commit 395f41e2cdac63e7581fb9574e5ac0f02556e34a upstream.

The check for size of isochronous packet payload just cares of the size of
IR context payload without the size of CIP header.

Cc: <stable@vger.kernel.org>
Fixes: f11453c7cc01 ("ALSA: firewire-lib: use 16 bytes IR context header to separate CIP header")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210513125652.110249-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 64559c103d9c36dabed116b22d2eaadd9c0dd7fd..e0faa6601966cae2a53e82e80b4a768d79997192 100644 (file)
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -633,18 +633,24 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
                               unsigned int *syt, unsigned int packet_index, unsigned int index)
 {
        const __be32 *cip_header;
+       unsigned int cip_header_size;
        int err;
 
        *payload_length = be32_to_cpu(ctx_header[0]) >> ISO_DATA_LENGTH_SHIFT;
-       if (*payload_length > s->ctx_data.tx.ctx_header_size +
-                                       s->ctx_data.tx.max_ctx_payload_length) {
+
+       if (!(s->flags & CIP_NO_HEADER))
+               cip_header_size = 8;
+       else
+               cip_header_size = 0;
+
+       if (*payload_length > cip_header_size + s->ctx_data.tx.max_ctx_payload_length) {
                dev_err(&s->unit->device,
                        "Detect jumbo payload: %04x %04x\n",
-                       *payload_length, s->ctx_data.tx.max_ctx_payload_length);
+                       *payload_length, cip_header_size + s->ctx_data.tx.max_ctx_payload_length);
                return -EIO;
        }
 
-       if (!(s->flags & CIP_NO_HEADER)) {
+       if (cip_header_size > 0) {
                cip_header = ctx_header + 2;
                err = check_cip_header(s, cip_header, *payload_length,
                                       data_blocks, data_block_counter, syt);