Commit 73ae31e5 authored Jan 13, 2011 by Eric B Munson Committed by Linus Torvalds Jan 13, 2011

hugetlb: fix handling of parse errors in sysfs



When parsing changes to the huge page pool sizes made from userspace via
the sysfs interface, bogus input values are being covered up by
nr_hugepages_store_common and nr_overcommit_hugepages_store returning 0
when strict_strtoul returns an error.  This can cause an infinite loop in
the nr_hugepages_store code.  This patch changes the return value for
these functions to -EINVAL when strict_strtoul returns an error.

Signed-off-by: Eric B Munson <emunson@mgebm.net>
Reported-by: CAI Qian <caiqian@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent adbe8726

mm/hugetlb.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -1375,10 +1375,8 @@ static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
		NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL \| __GFP_NORETRY);

		err = strict_strtoul(buf, 10, &count);
		if (err) {
		err = 0; /* This seems wrong */
		if (err)
		goto out;
		}

		h = kobj_to_hstate(kobj, &nid);
		if (h->order >= MAX_ORDER) {
		@@ -1469,7 +1467,7 @@ static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,

		err = strict_strtoul(buf, 10, &input);
		if (err)
		return 0;
		return err;

		spin_lock(&hugetlb_lock);
		h->nr_overcommit_huge_pages = input;

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