Commit 6f59e648 authored Feb 10, 2015 by Andrey Ryabinin Committed by Sasha Levin Mar 14, 2015

mm, hugetlb: remove unnecessary lower bound on sysctl handlers"?



commit 3cd7645de624939c38f5124b4ac15f8b35a1a8b7 upstream.

Commit ed4d4902 ("mm, hugetlb: remove hugetlb_zero and
hugetlb_infinity") replaced 'unsigned long hugetlb_zero' with 'int zero'
leading to out-of-bounds access in proc_doulongvec_minmax().  Use
'.extra1 = NULL' instead of '.extra1 = &zero'.  Passing NULL is
equivalent to passing minimal value, which is 0 for unsigned types.

Fixes: ed4d4902 ("mm, hugetlb: remove hugetlb_zero and hugetlb_infinity")
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Suggested-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent ac369918

kernel/sysctl.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -1232,7 +1232,6 @@ static struct ctl_table vm_table[] = {
		.maxlen = sizeof(unsigned long),
		.mode = 0644,
		.proc_handler = hugetlb_sysctl_handler,
		.extra1 = &zero,
		},
		#ifdef CONFIG_NUMA
		{
		@@ -1241,7 +1240,6 @@ static struct ctl_table vm_table[] = {
		.maxlen = sizeof(unsigned long),
		.mode = 0644,
		.proc_handler = &hugetlb_mempolicy_sysctl_handler,
		.extra1 = &zero,
		},
		#endif
		{
		@@ -1264,7 +1262,6 @@ static struct ctl_table vm_table[] = {
		.maxlen = sizeof(unsigned long),
		.mode = 0644,
		.proc_handler = hugetlb_overcommit_handler,
		.extra1 = &zero,
		},
		#endif
		{