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

From: Luiz Fernando N. Capitulino
Date: Mon Aug 30 2004 - 11:51:26 EST


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@xxxxxxxxxxxxxxxx>

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
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