[patch 56/56] genirq: NULL struct irq_descs member name in dynamic_irq_cleanup()

Greg KH
2009-02-11T00:48:32Z

[-- Attachment #1: genirq-null-struct-irq_desc-s-member-name-in-dynamic_irq_cleanup.patch --]
[-- Type: text/plain, Size: 1322 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------

From: Dean Nelson <dcn@sgi.com>

commit b6f3b7803a9231eddc36d0a2a6d2d8105ef89344 upstream.

If the member 'name' of the irq_desc structure happens to point to a
character string that is resident within a kernel module, problems ensue
if that module is rmmod'd (at which time dynamic_irq_cleanup() is called)
and then later show_interrupts() is called by someone.

It is also not a good thing if the character string resided in kmalloc'd
space that has been kfree'd (after having called dynamic_irq_cleanup()).
dynamic_irq_cleanup() fails to NULL the 'name' member and
show_interrupts() references it on a few architectures (like h8300, sh and
x86).

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
kernel/irq/chip.c | 1 +
1 file changed, 1 insertion(+)

--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -78,6 +78,7 @@ void dynamic_irq_cleanup(unsigned int ir
desc->chip_data = NULL;
desc->handle_irq = handle_bad_irq;
desc->chip = &no_irq_chip;
+ desc->name = NULL;
spin_unlock_irqrestore(&desc->lock, flags);
}