[PATCH 3.13 090/140] ALSA: bits vs bytes bug in snd_card_create()

Greg Kroah-Hartman
2014-02-04T21:12:53Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 4c3773eda49c872a3034382f8ec3080002e715bf upstream.

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/core/init.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -170,7 +170,7 @@ int snd_card_create(int idx, const char
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
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]) {