[PATCH 2.4] - drivers/pci/pci.c NULL pointer fix.

[PATCH 2.4] - drivers/pci/pci.c NULL pointer fix.

[Luiz Fernando N. Capitulino]

 Marcelo,

 This is another bug fix: the function pci/pci.c::pci_add_new_bus() does not
check the return of pci_alloc_bus(). If this function returns NULL, `child'
can be utilised.

 In the patch bellow I added the check, if the call that pci_scan_bridge()
is doing to pci_alloc_bus() return NULL, pci_scan_bridge() returns `max'
(Greg accepted this fix for 2.6, a while ago).

(against 2.4.28-pre2)


Signed-off-by: Luiz Capitulino <lcapitulino@conectiva.com.br>

 drivers/pci/pci.c |    9 +++++++++
 1 files changed, 9 insertions(+)


diff -X /home/capitulino/kernels/2.6/dontdiff -Nparu a/drivers/pci/pci.c a~/drivers/pci/pci.c
--- a/drivers/pci/pci.c	2004-08-07 20:26:05.000000000 -0300
+++ a~/drivers/pci/pci.c	2004-08-21 19:04:58.000000000 -0300
@@ -1238,6 +1238,8 @@ struct pci_bus * __devinit pci_add_new_b
 	 * Allocate a new bus, and inherit stuff from the parent..
 	 */
 	child = pci_alloc_bus();
+	if (!child)
+		return NULL;
 
 	list_add_tail(&child->node, &parent->children);
 	child->self = dev;
@@ -1291,7 +1293,11 @@ static int __devinit pci_scan_bridge(str
 		 */
 		if (pass)
 			return max;
+
 		child = pci_add_new_bus(bus, dev, 0);
+		if (!child)
+			return max;
+
 		child->primary = buses & 0xFF;
 		child->secondary = (buses >> 8) & 0xFF;
 		child->subordinate = (buses >> 16) & 0xFF;
@@ -1316,6 +1322,9 @@ static int __devinit pci_scan_bridge(str
 		pci_write_config_word(dev, PCI_STATUS, 0xffff);
 
 		child = pci_add_new_bus(bus, dev, ++max);
+		if (!child)
+			return max;
+
 		buses = (buses & 0xff000000)
 		      | ((unsigned int)(child->primary)     <<  0)
 		      | ((unsigned int)(child->secondary)   <<  8)

-- 
Luiz Fernando Capitulino

Re: [PATCH 2.4] - drivers/pci/pci.c NULL pointer fix.

[Marcelo Tosatti]

Applied, 

Thanks.

On Mon, Aug 30, 2004 at 12:47:33PM -0300, Luiz Fernando N. Capitulino wrote:
>  Marcelo,
> 
>  This is another bug fix: the function pci/pci.c::pci_add_new_bus() does not
> check the return of pci_alloc_bus(). If this function returns NULL, `child'
> can be utilised.
> 
>  In the patch bellow I added the check, if the call that pci_scan_bridge()
> is doing to pci_alloc_bus() return NULL, pci_scan_bridge() returns `max'
> (Greg accepted this fix for 2.6, a while ago).
> 
> (against 2.4.28-pre2)
> 
> 
> Signed-off-by: Luiz Capitulino <lcapitulino@conectiva.com.br>