ALSA: bits vs bytes bug in snd_card_create()

The test here is intended intended to prevent shift wrapping bugs when
we do "1U << idx2".  We should consider the number of bits in a u32
instead of the number of bytes.

[fix another chunk similarly by tiwai]

Fixes: 7bb2491b35a2 ('ALSA: Add kconfig to specify the max card numbers')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/init.c b/sound/core/init.c
index 1351f22..e3c93cd 100644 (file)
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -170,7 +170,7 @@ int snd_card_create(int idx, const char *xid,
        if (idx < 0) {
                for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
                        /* idx == -1 == 0xffff means: take any free slot */
-                       if (idx2 < sizeof(int) && !(idx & (1U << idx2)))
+                       if (idx2 < 32 && !(idx & (1U << idx2)))
                                continue;
                        if (!test_bit(idx2, snd_cards_lock)) {
                                if (module_slot_match(module, idx2)) {
@@ -183,7 +183,7 @@ int snd_card_create(int idx, const char *xid,
        if (idx < 0) {
                for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
                        /* idx == -1 == 0xffff means: take any free slot */
-                       if (idx2 < sizeof(int) && !(idx & (1U << idx2)))
+                       if (idx2 < 32 && !(idx & (1U << idx2)))
                                continue;
                        if (!test_bit(idx2, snd_cards_lock)) {
                                if (!slots[idx2] || !*slots[idx2]) {