2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Lars-Peter Clausen <[email protected]> Each control gets automatically assigned its numids when the control is created. The allocation is done by incrementing the numid by the amount of allocated numids per allocation. This means that excessive creation and destruction of controls (e.g. via SNDRV_CTL_IOCTL_ELEM_ADD/REMOVE) can cause the id to eventually overflow. Currently when this happens for the control that caused the overflow kctl->id.numid + kctl->count will also over flow causing it to be smaller than kctl->id.numid. Most of the code assumes that this is something that can not happen, so we need to make sure that it won't happen Signed-off-by: Lars-Peter Clausen <[email protected]> Acked-by: Jaroslav Kysela <[email protected]> Cc: <[email protected]> Signed-off-by: Takashi Iwai <[email protected]> (cherry picked from commit ac902c112d90a89e59916f751c2745f4dbdbb4bd) [wt: part 2 of CVE-2014-4656] Signed-off-by: Willy Tarreau <[email protected]> --- sound/core/control.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sound/core/control.c b/sound/core/control.c index 80bb3ed..d7f4644 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -278,6 +278,10 @@ static unsigned int snd_ctl_hole_check(struct snd_card *card, { struct snd_kcontrol *kctl; + /* Make sure that the ids assigned to the control do not wrap around */ + if (card->last_numid >= UINT_MAX - count) + card->last_numid = 0; + list_for_each_entry(kctl, &card->controls, list) { if ((kctl->id.numid <= card->last_numid && kctl->id.numid + kctl->count > card->last_numid) || -- 1.7.12.2.21.g234cd45.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
