On Wed, Mar 20, 2019 at 03:26:48PM -0400, Qian Cai wrote:
> Running LTP oom01 in a tight loop or memory stress testing put the
> system in a low-memory situation could triggers random memory
> corruption like page flag corruption below due to in
> fast_isolate_freepages(), if isolation fails, next_search_order() does
> not abort the search immediately could lead to improper accesses.
>
> UBSAN: Undefined behaviour in ./include/linux/mm.h:1195:50
> index 7 is out of range for type 'zone [5]'
> Call Trace:
> dump_stack+0x62/0x9a
> ubsan_epilogue+0xd/0x7f
> __ubsan_handle_out_of_bounds+0x14d/0x192
> __isolate_free_page+0x52c/0x600
> compaction_alloc+0x886/0x25f0
> unmap_and_move+0x37/0x1e70
> migrate_pages+0x2ca/0xb20
> compact_zone+0x19cb/0x3620
> kcompactd_do_work+0x2df/0x680
> kcompactd+0x1d8/0x6c0
> kthread+0x32c/0x3f0
> ret_from_fork+0x35/0x40
> ------------[ cut here ]------------
> kernel BUG at mm/page_alloc.c:3124!
> invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
> RIP: 0010:__isolate_free_page+0x464/0x600
> RSP: 0000:ffff888b9e1af848 EFLAGS: 00010007
> RAX: 0000000030000000 RBX: ffff888c39fcf0f8 RCX: 0000000000000000
> RDX: 1ffff111873f9e25 RSI: 0000000000000004 RDI: ffffed1173c35ef6
> RBP: ffff888b9e1af898 R08: fffffbfff4fc2461 R09: fffffbfff4fc2460
> R10: fffffbfff4fc2460 R11: ffffffffa7e12303 R12: 0000000000000008
> R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000007
> FS: 0000000000000000(0000) GS:ffff888ba8e80000(0000)
> knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fc7abc00000 CR3: 0000000752416004 CR4: 00000000001606a0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> compaction_alloc+0x886/0x25f0
> unmap_and_move+0x37/0x1e70
> migrate_pages+0x2ca/0xb20
> compact_zone+0x19cb/0x3620
> kcompactd_do_work+0x2df/0x680
> kcompactd+0x1d8/0x6c0
> kthread+0x32c/0x3f0
> ret_from_fork+0x35/0x40
>
> Fixes: dbe2d4e4f12e ("mm, compaction: round-robin the order while searching the free lists for a target")
> Signed-off-by: Qian Cai <cai@xxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
--
Mel Gorman
SUSE Labs
