diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2010-08-03 11:33:45 +0400 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2010-08-03 18:43:13 +0400 |
| commit | 127c03cdbad9bd5af5d7f33bd31a1015a90cb77f (patch) | |
| tree | a948c5814a7d2e82801927bc3d5f06d3d7056ab0 /drivers/pcmcia | |
| parent | 0f52e86ded65749c6037473013ad77b2afa4f68d (diff) | |
| download | linux-127c03cdbad9bd5af5d7f33bd31a1015a90cb77f.tar.xz | |
pcmcia: avoid buffer overflow in pcmcia_setup_isa_irq
NR_IRQS may be as low as 16, causing a (harmless?) buffer overflow in
pcmcia_setup_isa_irq():
static u8 pcmcia_used_irq[NR_IRQS];
...
if ((try < 32) && pcmcia_used_irq[irq])
continue;
This is read-only, so if this address would be non-zero, it would just
mean we would not attempt an IRQ >= NR_IRQS -- which would fail anyway!
And as request_irq() fails for an irq >= NR_IRQS, the setting code path:
pcmcia_used_irq[irq]++;
is never reached as well.
Reported-by: Christoph Fritz <chf.fritz@googlemail.com>
CC: stable@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
Diffstat (limited to 'drivers/pcmcia')
| -rw-r--r-- | drivers/pcmcia/pcmcia_resource.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/pcmcia/pcmcia_resource.c b/drivers/pcmcia/pcmcia_resource.c index d48437f83acf..54aa1c238cb3 100644 --- a/drivers/pcmcia/pcmcia_resource.c +++ b/drivers/pcmcia/pcmcia_resource.c @@ -677,7 +677,7 @@ EXPORT_SYMBOL(__pcmcia_request_exclusive_irq); #ifdef CONFIG_PCMCIA_PROBE /* mask of IRQs already reserved by other cards, we should avoid using them */ -static u8 pcmcia_used_irq[NR_IRQS]; +static u8 pcmcia_used_irq[32]; static irqreturn_t test_action(int cpl, void *dev_id) { @@ -700,6 +700,9 @@ static int pcmcia_setup_isa_irq(struct pcmcia_device *p_dev, int type) for (try = 0; try < 64; try++) { irq = try % 32; + if (irq > NR_IRQS) + continue; + /* marked as available by driver, not blocked by userspace? */ if (!((mask >> irq) & 1)) continue; |