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 16:43:50 -0700 |
| commit | e9237ad37ea237e7d84581d72650d69701559f65 (patch) | |
| tree | 6f8746104bb88eceb4e495763e0ae08190e8fb92 /drivers | |
| parent | 72a85b3b5ae9508964df640f005110dfbcfe1f19 (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')
| -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 7c3d03bb4f30..cfcf868a9ffc 100644 --- a/drivers/pcmcia/pcmcia_resource.c +++ b/drivers/pcmcia/pcmcia_resource.c @@ -41,7 +41,7 @@ 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 static int pcmcia_adjust_io_region(struct resource *res, unsigned long start, @@ -768,6 +768,9 @@ 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; |