The patch titled
Subject: hugetlb: clean up potential spectre issue warnings
has been added to the -mm tree. Its filename is
hugetlb-clean-up-potential-spectre-issue-warnings.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/hugetlb-clean-up-potential-spectre-issue-warnings.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/hugetlb-clean-up-potential-spectre-issue-warnings.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Subject: hugetlb: clean up potential spectre issue warnings
Recently introduced code allows numa nodes to be specified on the kernel
command line for hugetlb allocations or CMA reservations. The node values
are user specified and used as indicies into arrays. This generated the
following smatch warnings:
mm/hugetlb.c:4170 hugepages_setup() warn: potential spectre issue 'default_hugepages_in_node' [w]
mm/hugetlb.c:4172 hugepages_setup() warn: potential spectre issue 'parsed_hstate->max_huge_pages_node' [w]
mm/hugetlb.c:6898 cmdline_parse_hugetlb_cma() warn: potential spectre issue 'hugetlb_cma_size_in_node' [w] (local cap)
Clean up by using array_index_nospec to sanitize array indicies.
Link: https://lkml.kernel.org/r/20220217234218.192885-1-mike.kravetz@xxxxxxxxxx
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Zhenguo Yao <yaozhenguo1@xxxxxxxxx>
Cc: Liu Yuntao <liuyuntao10@xxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/mm/hugetlb.c~hugetlb-clean-up-potential-spectre-issue-warnings
+++ a/mm/hugetlb.c
@@ -31,6 +31,7 @@
#include <linux/llist.h>
#include <linux/cma.h>
#include <linux/migrate.h>
+#include <linux/nospec.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
@@ -4161,7 +4162,7 @@ static int __init hugepages_setup(char *
}
if (tmp >= nr_online_nodes)
goto invalid;
- node = tmp;
+ node = array_index_nospec(tmp, nr_online_nodes);
p += count + 1;
/* Parse hugepages */
if (sscanf(p, "%lu%n", &tmp, &count) != 1)
@@ -6889,9 +6890,9 @@ static int __init cmdline_parse_hugetlb_
break;
if (s[count] == ':') {
- nid = tmp;
- if (nid < 0 || nid >= MAX_NUMNODES)
+ if (tmp < 0 || tmp >= MAX_NUMNODES)
break;
+ nid = array_index_nospec(tmp, MAX_NUMNODES);
s += count + 1;
tmp = memparse(s, &s);
_
Patches currently in -mm which might be from mike.kravetz@xxxxxxxxxx are
selftests-vm-cleanup-hugetlb-file-after-mremap-test.patch
mm-enable-madv_dontneed-for-hugetlb-mappings.patch
selftests-vm-add-hugetlb-madvise-madv_dontneed-madv_remove-test.patch
userfaultfd-selftests-enable-hugetlb-remap-and-remove-event-testing.patch
hugetlb-clean-up-potential-spectre-issue-warnings.patch
