• Qian Cai's avatar
    mm/compaction.c: abort search if isolation fails · 5b56d996
    Qian Cai authored
    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
    
    Link: http://lkml.kernel.org/r/20190320192648.52499-1-cai@lca.pw
    Fixes: dbe2d4e4 ("mm, compaction: round-robin the order while searching the free lists for a target")
    Signed-off-by: default avatarQian Cai <cai@lca.pw>
    Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
    Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
    Cc: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
    Cc: Vlastimil Babka <vbabka@suse.cz>
    Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
    Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
    5b56d996
compaction.c 75 KB