ALSA: bebob: use address returned by kmalloc() instead of kernel stack for streaming...

When executing 'fw_run_transaction()' with 'TCODE_WRITE_BLOCK_REQUEST',
an address of 'payload' argument is used for streaming DMA mapping by
'firewire_ohci' module if 'size' argument is larger than 8 byte.
Although in this case the address should not be on kernel stack, current
implementation of ALSA bebob driver uses data in kernel stack for a cue
to boot M-Audio devices. This often brings unexpected result, especially
for a case of CONFIG_VMAP_STACK=y.

This commit fixes the bug.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=201021
Reference: https://forum.manjaro.org/t/firewire-m-audio-410-driver-wont-load-firmware/51165
Fixes: a2b2a7798fb6('ALSA: bebob: Send a cue to load firmware for M-Audio Firewire series')
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/bebob/bebob_maudio.c b/sound/firewire/bebob/bebob_maudio.c
index bd55620..0c5a4cb 100644 (file)
--- a/sound/firewire/bebob/bebob_maudio.c
+++ b/sound/firewire/bebob/bebob_maudio.c
@@ -96,17 +96,13 @@ int snd_bebob_maudio_load_firmware(struct fw_unit *unit)
        struct fw_device *device = fw_parent_device(unit);
        int err, rcode;
        u64 date;
-       __le32 cues[3] = {
-               cpu_to_le32(MAUDIO_BOOTLOADER_CUE1),
-               cpu_to_le32(MAUDIO_BOOTLOADER_CUE2),
-               cpu_to_le32(MAUDIO_BOOTLOADER_CUE3)
-       };
+       __le32 *cues;
 
        /* check date of software used to build */
        err = snd_bebob_read_block(unit, INFO_OFFSET_SW_DATE,
                                   &date, sizeof(u64));
        if (err < 0)
-               goto end;
+               return err;
        /*
         * firmware version 5058 or later has date later than "20070401", but
         * 'date' is not null-terminated.
@@ -114,20 +110,28 @@ int snd_bebob_maudio_load_firmware(struct fw_unit *unit)
        if (date < 0x3230303730343031LL) {
                dev_err(&unit->device,
                        "Use firmware version 5058 or later\n");
-               err = -ENOSYS;
-               goto end;
+               return -ENXIO;
        }
 
+       cues = kmalloc_array(3, sizeof(*cues), GFP_KERNEL);
+       if (!cues)
+               return -ENOMEM;
+
+       cues[0] = cpu_to_le32(MAUDIO_BOOTLOADER_CUE1);
+       cues[1] = cpu_to_le32(MAUDIO_BOOTLOADER_CUE2);
+       cues[2] = cpu_to_le32(MAUDIO_BOOTLOADER_CUE3);
+
        rcode = fw_run_transaction(device->card, TCODE_WRITE_BLOCK_REQUEST,
                                   device->node_id, device->generation,
                                   device->max_speed, BEBOB_ADDR_REG_REQ,
-                                  cues, sizeof(cues));
+                                  cues, 3 * sizeof(*cues));
+       kfree(cues);
        if (rcode != RCODE_COMPLETE) {
                dev_err(&unit->device,
                        "Failed to send a cue to load firmware\n");
                err = -EIO;
        }
-end:
+
        return err;
 }