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* [PATCH] xen, cpu_hotplug: Prevent an out of bounds access
@ 2019-03-07  5:41 ` Dan Carpenter
  0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2019-03-07  5:41 UTC (permalink / raw)
  To: Boris Ostrovsky, Alex Nixon
  Cc: Juergen Gross, xen-devel, Stefano Stabellini, kernel-janitors

The "cpu" variable comes from the sscanf() so Smatch marks it as
untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
cpu_possible() or it results in an out of bounds access.

Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/xen/cpu_hotplug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index b1357aa4bc55..f192b6f42da9 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -54,7 +54,7 @@ static int vcpu_online(unsigned int cpu)
 }
 static void vcpu_hotplug(unsigned int cpu)
 {
-	if (!cpu_possible(cpu))
+	if (cpu >= nr_cpu_ids || !cpu_possible(cpu))
 		return;
 
 	switch (vcpu_online(cpu)) {
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH] xen, cpu_hotplug: Prevent an out of bounds access
@ 2019-03-07  5:41 ` Dan Carpenter
  0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2019-03-07  5:41 UTC (permalink / raw)
  To: Boris Ostrovsky, Alex Nixon
  Cc: Juergen Gross, xen-devel, Stefano Stabellini, kernel-janitors

The "cpu" variable comes from the sscanf() so Smatch marks it as
untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
cpu_possible() or it results in an out of bounds access.

Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/xen/cpu_hotplug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index b1357aa4bc55..f192b6f42da9 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -54,7 +54,7 @@ static int vcpu_online(unsigned int cpu)
 }
 static void vcpu_hotplug(unsigned int cpu)
 {
-	if (!cpu_possible(cpu))
+	if (cpu >= nr_cpu_ids || !cpu_possible(cpu))
 		return;
 
 	switch (vcpu_online(cpu)) {
-- 
2.17.1


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] xen, cpu_hotplug: Prevent an out of bounds access
  2019-03-07  5:41 ` Dan Carpenter
@ 2019-03-07  7:12   ` Juergen Gross
  -1 siblings, 0 replies; 6+ messages in thread
From: Juergen Gross @ 2019-03-07  7:12 UTC (permalink / raw)
  To: Dan Carpenter, Boris Ostrovsky, Alex Nixon
  Cc: xen-devel, Stefano Stabellini, kernel-janitors

On 07/03/2019 06:41, Dan Carpenter wrote:
> The "cpu" variable comes from the sscanf() so Smatch marks it as
> untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
> cpu_possible() or it results in an out of bounds access.
> 
> Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] xen, cpu_hotplug: Prevent an out of bounds access
@ 2019-03-07  7:12   ` Juergen Gross
  0 siblings, 0 replies; 6+ messages in thread
From: Juergen Gross @ 2019-03-07  7:12 UTC (permalink / raw)
  To: Dan Carpenter, Boris Ostrovsky, Alex Nixon
  Cc: xen-devel, Stefano Stabellini, kernel-janitors

On 07/03/2019 06:41, Dan Carpenter wrote:
> The "cpu" variable comes from the sscanf() so Smatch marks it as
> untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
> cpu_possible() or it results in an out of bounds access.
> 
> Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] xen, cpu_hotplug: Prevent an out of bounds access
  2019-03-07  5:41 ` Dan Carpenter
@ 2019-03-08 17:16   ` Juergen Gross
  -1 siblings, 0 replies; 6+ messages in thread
From: Juergen Gross @ 2019-03-08 17:16 UTC (permalink / raw)
  To: Dan Carpenter, Boris Ostrovsky, Alex Nixon
  Cc: xen-devel, Stefano Stabellini, kernel-janitors

On 07/03/2019 06:41, Dan Carpenter wrote:
> The "cpu" variable comes from the sscanf() so Smatch marks it as
> untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
> cpu_possible() or it results in an out of bounds access.
> 
> Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Pushed to xen/tip.git for-linus-5.1a


Juergen

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] xen, cpu_hotplug: Prevent an out of bounds access
@ 2019-03-08 17:16   ` Juergen Gross
  0 siblings, 0 replies; 6+ messages in thread
From: Juergen Gross @ 2019-03-08 17:16 UTC (permalink / raw)
  To: Dan Carpenter, Boris Ostrovsky, Alex Nixon
  Cc: xen-devel, Stefano Stabellini, kernel-janitors

On 07/03/2019 06:41, Dan Carpenter wrote:
> The "cpu" variable comes from the sscanf() so Smatch marks it as
> untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
> cpu_possible() or it results in an out of bounds access.
> 
> Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Pushed to xen/tip.git for-linus-5.1a


Juergen

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-03-08 17:16 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-07  5:41 [PATCH] xen, cpu_hotplug: Prevent an out of bounds access Dan Carpenter
2019-03-07  5:41 ` Dan Carpenter
2019-03-07  7:12 ` Juergen Gross
2019-03-07  7:12   ` Juergen Gross
2019-03-08 17:16 ` Juergen Gross
2019-03-08 17:16   ` Juergen Gross

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