| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 258/639] xen, cpu_hotplug: Prevent an out of bounds access | Date | Fri, 24 Jan 2020 10:27:08 +0100 |
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From: Dan Carpenter <dan.carpenter@oracle.com>
[ Upstream commit 201676095dda7e5b31a5e1d116d10fc22985075e ]
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> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 b1357aa4bc552..f192b6f42da9f 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)) { -- 2.20.1
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