diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2010-08-03 09:33:45 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-26 16:41:53 -0700 |
| commit | 47084480bf6f0c78be4d3a82020fa18f90425f26 (patch) | |
| tree | e6455f8d4b1ca31ce8c8dce32b00b3739615a281 /drivers/pcmcia | |
| parent | 94739dc4e2da1ade4a87b53de97399c2ec0dd83b (diff) | |
pcmcia: avoid buffer overflow in pcmcia_setup_isa_irq
commit 127c03cdbad9bd5af5d7f33bd31a1015a90cb77f upstream.
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>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 d919e96c0af..7905285f707 100644 --- a/drivers/pcmcia/pcmcia_resource.c +++ b/drivers/pcmcia/pcmcia_resource.c @@ -39,7 +39,7 @@ module_param(io_speed, int, 0444); #ifdef CONFIG_PCMCIA_PROBE #include <asm/irq.h> /* 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]; #endif @@ -719,6 +719,9 @@ int pcmcia_request_irq(struct pcmcia_device *p_dev, irq_req_t *req) for (try = 0; try < 64; try++) { irq = try % 32; + if (irq > NR_IRQS) + continue; + /* marked as available by driver, and not blocked by userspace? */ if (!((mask >> irq) & 1)) continue; |