4.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiri Olsa <jolsa@xxxxxxxxxx>
commit 7f00f388712b29005782bad7e4b25942620f3b9c upstream.
The schemata lock is released before freeing the resource's temporary
tmp_cbms allocation. That's racy versus another write which allocates and
uses new temporary storage, resulting in memory leaks, freeing in use
memory, double a free or any combination of those.
Move the unlock after the release code.
Fixes: 60ec2440c63d ("x86/intel_rdt: Add schemata file")
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Shaohua Li <shli@xxxxxx>
Link: http://lkml.kernel.org/r/20170411071446.15241-1-jolsa@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/intel_rdt_schemata.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/intel_rdt_schemata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_schemata.c
@@ -200,11 +200,11 @@ ssize_t rdtgroup_schemata_write(struct k
}
out:
- rdtgroup_kn_unlock(of->kn);
for_each_enabled_rdt_resource(r) {
kfree(r->tmp_cbms);
r->tmp_cbms = NULL;
}
+ rdtgroup_kn_unlock(of->kn);
return ret ?: nbytes;
}