Messages in this thread Patch in this message | | | Date | Tue, 15 Feb 2011 16:14:23 -0800 | From | Greg KH <> | Subject | [206/272] perf: Validate cpu early in perf_event_alloc() |
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2.6.37-stable review patch. If anyone has any objections, please let us know.
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From: Oleg Nesterov <oleg@redhat.com>
commit 66832eb4baaaa9abe4c993ddf9113a79e39b9915 upstream.
Starting from perf_event_alloc()->perf_init_event(), the kernel assumes that event->cpu is either -1 or the valid CPU number.
Change perf_event_alloc() to validate this argument early. This also means we can remove the similar check in find_get_context().
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> LKML-Reference: <20110118161032.GC693@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- kernel/perf_event.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
--- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -2105,9 +2105,6 @@ find_get_context(struct pmu *pmu, struct if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) return ERR_PTR(-EACCES); - if (cpu < 0 || cpu >= nr_cpumask_bits) - return ERR_PTR(-EINVAL); - /* * We could be clever and allow to attach a event to an * offline CPU and activate it when the CPU comes up, but @@ -5304,6 +5301,11 @@ perf_event_alloc(struct perf_event_attr struct hw_perf_event *hwc; long err; + if ((unsigned)cpu >= nr_cpu_ids) { + if (!task || cpu != -1) + return ERR_PTR(-EINVAL); + } + event = kzalloc(sizeof(*event), GFP_KERNEL); if (!event) return ERR_PTR(-ENOMEM); @@ -5352,7 +5354,7 @@ perf_event_alloc(struct perf_event_attr if (!overflow_handler && parent_event) overflow_handler = parent_event->overflow_handler; - + event->overflow_handler = overflow_handler; if (attr->disabled)
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