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Groups > linux.kernel > #1386444
| From | Vlastimil Babka <vbabka@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH mmotm 2/3] mm, compaction: fix crash in get_pfnblock_flags_mask() from isolate_freepages(): |
| Date | 2016-04-25 15:40 +0200 |
| Message-ID | <rrOU1-6G6-13@gated-at.bofh.it> (permalink) |
| References | <rrOU1-6G6-5@gated-at.bofh.it> <rrOU1-6G6-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
In isolate_freepages(), low_pfn was mistakenly initialized to pageblock_start_pfn() instead of pageblock_end_pfn(), creating a possible underflow, as described by Hugh: There's a case when that "block_start_pfn -= pageblock_nr_pages" loop can pass through 0 and end up trying to access a pageblock before the start of the mem_map[]. Fixes: mmotm mm-compaction-wrap-calculating-first-and-last-pfn-of-pageblock.patch Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> --- mm/compaction.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index 759c3ac73ced..6a49d1b35515 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -999,7 +999,7 @@ static void isolate_freepages(struct compact_control *cc) block_start_pfn = pageblock_start_pfn(cc->free_pfn); block_end_pfn = min(block_start_pfn + pageblock_nr_pages, zone_end_pfn(zone)); - low_pfn = pageblock_start_pfn(cc->migrate_pfn); + low_pfn = pageblock_end_pfn(cc->migrate_pfn); /* * Isolate free pages until enough are available to migrate the -- 2.8.1
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[PATCH 0/3] mainline and mmotm compaction fixes Vlastimil Babka <vbabka@suse.cz> - 2016-04-25 15:40 +0200
[PATCH mmotm 2/3] mm, compaction: fix crash in get_pfnblock_flags_mask() from isolate_freepages(): Vlastimil Babka <vbabka@suse.cz> - 2016-04-25 15:40 +0200
[PATCH 0/3] mainline and mmotm compaction fixes Vlastimil Babka <vbabka@suse.cz> - 2016-04-25 15:40 +0200
[PATCH mmotm 3/3] mm, compaction: prevent nr_isolated_* from going negative Vlastimil Babka <vbabka@suse.cz> - 2016-04-25 15:40 +0200
Re: [PATCH mmotm 3/3] mm, compaction: prevent nr_isolated_* from going negative Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-04-26 03:00 +0200
Re: [PATCH mmotm 3/3] mm, compaction: prevent nr_isolated_* from going negative Vlastimil Babka <vbabka@suse.cz> - 2016-04-26 21:50 +0200
Re: [PATCH mmotm 3/3] mm, compaction: prevent nr_isolated_* from going negative Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-04-27 03:00 +0200
Re: [PATCH 0/3] mainline and mmotm compaction fixes Michal Hocko <mhocko@kernel.org> - 2016-04-25 16:40 +0200
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