linux/mm
Minchan Kim ce2684254b mm: validate pmd after splitting
syzbot reported the following KASAN splat:

  general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
  KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
  CPU: 1 PID: 6826 Comm: syz-executor142 Not tainted 5.9.0-rc4-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:__lock_acquire+0x84/0x2ae0 kernel/locking/lockdep.c:4296
  Code: ff df 8a 04 30 84 c0 0f 85 e3 16 00 00 83 3d 56 58 35 08 00 0f 84 0e 17 00 00 83 3d 25 c7 f5 07 00 74 2c 4c 89 e8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ef e8 3e d1 5a 00 48 be 00 00 00 00 00 fc
  RSP: 0018:ffffc90004b9f850 EFLAGS: 00010006
  Call Trace:
    lock_acquire+0x140/0x6f0 kernel/locking/lockdep.c:5006
    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
    _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
    spin_lock include/linux/spinlock.h:354 [inline]
    madvise_cold_or_pageout_pte_range+0x52f/0x25c0 mm/madvise.c:389
    walk_pmd_range mm/pagewalk.c:89 [inline]
    walk_pud_range mm/pagewalk.c:160 [inline]
    walk_p4d_range mm/pagewalk.c:193 [inline]
    walk_pgd_range mm/pagewalk.c:229 [inline]
    __walk_page_range+0xe7b/0x1da0 mm/pagewalk.c:331
    walk_page_range+0x2c3/0x5c0 mm/pagewalk.c:427
    madvise_pageout_page_range mm/madvise.c:521 [inline]
    madvise_pageout mm/madvise.c:557 [inline]
    madvise_vma mm/madvise.c:946 [inline]
    do_madvise+0x12d0/0x2090 mm/madvise.c:1145
    __do_sys_madvise mm/madvise.c:1171 [inline]
    __se_sys_madvise mm/madvise.c:1169 [inline]
    __x64_sys_madvise+0x76/0x80 mm/madvise.c:1169
    do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

The backing vma was shmem.

In case of split page of file-backed THP, madvise zaps the pmd instead
of remapping of sub-pages.  So we need to check pmd validity after
split.

Reported-by: syzbot+ecf80462cb7d5d552bc7@syzkaller.appspotmail.com
Fixes: 1a4e58cce8 ("mm: introduce MADV_PAGEOUT")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26 10:48:08 -07:00
..
kasan Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
backing-dev.c writeback: remove struct bdi_writeback_congested 2020-07-08 17:05:53 -06:00
balloon_compaction.c mm/balloon_compaction: suppress allocation warnings 2019-09-04 07:42:01 -04:00
cleancache.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
cma_debug.c debugfs: make sure we can remove u32_array files cleanly 2020-07-10 13:54:00 -07:00
cma.c cma: don't quit at first error when activating reserved areas 2020-08-12 10:57:57 -07:00
cma.h mm: cma: fix the name of CMA areas 2020-08-12 10:57:57 -07:00
compaction.c mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
debug_page_ref.c
debug_vm_pgtable.c Documentation/mm: add descriptions for arch page table helpers 2020-08-07 11:33:23 -07:00
debug.c mm, dump_page: do not crash with bad compound_mapcount() 2020-08-07 11:33:23 -07:00
dmapool.c mm/dmapool.c: micro-optimisation remove unnecessary branch 2020-04-07 10:43:42 -07:00
early_ioremap.c mm/early_ioremap.c: use %pa to print resource_size_t variables 2020-01-31 10:30:38 -08:00
fadvise.c mm: return void from various readahead functions 2020-06-02 10:59:06 -07:00
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm: fix wake_page_function() comment typos 2020-09-20 10:38:47 -07:00
frame_vector.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
frontswap.c mm/frontswap: mark various intentional data races 2020-08-14 19:56:56 -07:00
gup_benchmark.c mm/gup_benchmark: support pin_user_pages() and related calls 2020-04-02 09:35:27 -07:00
gup.c Merge branch 'simplify-do_wp_page' 2020-09-04 09:31:54 -07:00
highmem.c mm, x86/mm: Untangle address space layout definitions from basic pgtable type definitions 2019-12-10 10:12:55 +01:00
hmm.c mm: do page fault accounting in handle_mm_fault 2020-08-12 10:58:02 -07:00
huge_memory.c mm/thp: fix __split_huge_pmd_locked() for migration PMD 2020-09-19 13:13:38 -07:00
hugetlb_cgroup.c hugetlb_cgroup: convert comma to semicolon 2020-08-21 09:52:52 -07:00
hugetlb.c mm/hugetlb: fix a race between hugetlb sysctl handlers 2020-09-05 12:14:30 -07:00
hwpoison-inject.c mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
init-mm.c mmap locking API: add MMAP_LOCK_INITIALIZER 2020-06-09 09:39:14 -07:00
internal.h mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
ioremap.c mm: move p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
Kconfig mm/sparse: cleanup the code surrounding memory_present() 2020-08-07 11:33:27 -07:00
Kconfig.debug treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
khugepaged.c mm/khugepaged.c: fix khugepaged's request size in collapse_file 2020-09-05 12:14:30 -07:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak: silence KCSAN splats in checksum 2020-08-14 19:56:56 -07:00
ksm.c ksm: reinstate memcg charge on copied pages 2020-09-19 13:13:38 -07:00
list_lru.c mm/list_lru: fix a data race in list_lru_count_one 2020-08-14 19:56:57 -07:00
maccess.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
madvise.c mm: validate pmd after splitting 2020-09-26 10:48:08 -07:00
Makefile mm: move lib/ioremap.c to mm/ 2020-08-07 11:33:26 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: update huge page-table entry callbacks 2020-04-02 09:35:29 -07:00
memblock.c mm/memblock: expose only miminal interface to add/walk physmem 2020-07-10 15:08:09 +02:00
memcontrol.c memcg: fix use-after-free in uncharge_batch 2020-09-05 12:14:29 -07:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory_hotplug.c mm/memory_hotplug: drain per-cpu pages again during memory offline 2020-09-19 13:13:39 -07:00
memory-failure.c mm/migrate: introduce a standard migration target allocation function 2020-08-12 10:58:02 -07:00
memory.c mm: fix misplaced unlock_page in do_wp_page() 2020-09-24 08:41:32 -07:00
mempolicy.c mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
mempool.c mm/mempool: fix a data race in mempool_free() 2020-08-14 19:56:57 -07:00
memremap.c memremap: rename MEMORY_DEVICE_DEVDAX to MEMORY_DEVICE_GENERIC 2020-09-04 09:59:59 +02:00
memtest.c
migrate.c mm: migration of hugetlbfs page skip memcg 2020-09-19 13:13:38 -07:00
mincore.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
mlock.c mlock: fix unevictable_pgs event counts on THP 2020-09-19 13:13:38 -07:00
mm_init.c mm: adjust vm_committed_as_batch according to vm overcommit policy 2020-08-07 11:33:26 -07:00
mmap.c mm: remove unnecessary wrapper function do_mmap_pgoff() 2020-08-07 11:33:27 -07:00
mmu_gather.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
mmu_notifier.c mm: mmu_notifier: fix and extend kerneldoc 2020-08-12 10:57:57 -07:00
mmzone.c
mprotect.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
mremap.c mm/mremap: start addresses are properly aligned 2020-08-07 11:33:27 -07:00
msync.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
nommu.c mm/nommu.c: delete duplicated words 2020-08-12 10:57:58 -07:00
oom_kill.c mm, oom: show process exiting information in __oom_kill_process() 2020-08-12 10:57:56 -07:00
page_alloc.c mm, page_alloc: fix core hung in free_pcppages_bulk() 2020-08-21 09:52:53 -07:00
page_counter.c mm/page_counter: fix various data races at memsw 2020-08-14 19:56:57 -07:00
page_ext.c mm/page_ext.c: drop pfn_present() check when onlining 2020-04-07 10:43:40 -07:00
page_idle.c mm/page_idle.c: skip offline pages 2020-06-08 11:05:55 -07:00
page_io.c mm/page_io: mark various intentional data races 2020-08-14 19:56:56 -07:00
page_isolation.c mm/memory_hotplug: drain per-cpu pages again during memory offline 2020-09-19 13:13:39 -07:00
page_owner.c mm: rename gfpflags_to_migratetype to gfp_migratetype for same convention 2020-06-03 20:09:45 -07:00
page_poison.c mm/page_poison.c: fix a typo in a comment 2019-09-24 15:54:08 -07:00
page_reporting.c mm/page_reporting: add budget limit on how many pages can be reported per pass 2020-04-07 10:43:39 -07:00
page_reporting.h mm: introduce include/linux/pgtable.h 2020-06-09 09:39:13 -07:00
page_vma_mapped.c mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
page-writeback.c mm: remove vm_total_pages 2020-08-07 11:33:28 -07:00
pagewalk.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
percpu-internal.h mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-km.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-stats.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-vm.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu.c percpu: fix first chunk size calculation for populated bitmap 2020-09-17 17:34:39 +00:00
pgalloc-track.h mm: move p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
pgtable-generic.c mm: introduce include/linux/pgtable.h 2020-06-09 09:39:13 -07:00
process_vm_access.c mm/gup: remove task_struct pointer for all gup code 2020-08-12 10:58:04 -07:00
ptdump.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
readahead.c mm: use memalloc_nofs_save in readahead path 2020-06-02 10:59:07 -07:00
rmap.c mm/rmap: fixup copying of soft dirty and uffd ptes 2020-09-05 12:14:30 -07:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
shmem.c tmpfs: restore functionality of nr_inodes=0 2020-09-19 13:13:38 -07:00
shuffle.c mm/shuffle: remove dynamic reconfiguration 2020-08-07 11:33:29 -07:00
shuffle.h mm/shuffle: remove dynamic reconfiguration 2020-08-07 11:33:29 -07:00
slab_common.c mm/slab_common.c: delete duplicated word 2020-08-12 10:57:58 -07:00
slab.c mm: slab: fix potential double free in ___cache_free 2020-09-26 10:15:01 -07:00
slab.h mm: slab: rename (un)charge_slab_page() to (un)account_slab_page() 2020-08-07 11:33:25 -07:00
slob.c mm: memcg: convert vmstat slab counters to bytes 2020-08-07 11:33:24 -07:00
slub.c mm: slub: fix conversion of freelist_corrupted() 2020-09-05 12:14:29 -07:00
sparse-vmemmap.c mm/sparse: only sub-section aligned range would be populated 2020-08-07 11:33:27 -07:00
sparse.c mm/sparse: cleanup the code surrounding memory_present() 2020-08-07 11:33:27 -07:00
swap_cgroup.c mm: memcontrol: make swap tracking an integral part of memory control 2020-06-03 20:09:48 -07:00
swap_slots.c mm/swap_slots.c: remove redundant check for swap_slot_cache_initialized 2020-08-07 11:33:24 -07:00
swap_state.c mm/swap_state: mark various intentional data races 2020-08-14 19:56:57 -07:00
swap.c mlock: fix unevictable_pgs event counts on THP 2020-09-19 13:13:38 -07:00
swapfile.c mm/swapfile: fix and annotate various data races 2020-08-14 19:56:57 -07:00
truncate.c mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
usercopy.c mm/usercopy.c: delete duplicated word 2020-08-12 10:57:58 -07:00
userfaultfd.c mm/vmscan: protect the workingset on anonymous LRU 2020-08-12 10:57:55 -07:00
util.c mm: remove unnecessary wrapper function do_mmap_pgoff() 2020-08-07 11:33:27 -07:00
vmacache.c kernel: better document the use_mm/unuse_mm API contract 2020-06-10 19:14:18 -07:00
vmalloc.c mm/vunmap: add cond_resched() in vunmap_pmd_range 2020-08-21 09:52:53 -07:00
vmpressure.c mm: vmpressure: use mem_cgroup_is_root API 2020-04-02 09:35:31 -07:00
vmscan.c mm: fix check_move_unevictable_pages() on THP 2020-09-19 13:13:38 -07:00
vmstat.c Merge branch 'simplify-do_wp_page' 2020-09-04 09:31:54 -07:00
workingset.c mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
z3fold.c mm/z3fold: silence kmemleak false positives of slots 2020-05-28 11:35:40 -07:00
zbud.c mm: use false for bool variable 2020-06-04 19:06:24 -07:00
zpool.c mm/zpool.c: delete duplicated word and fix grammar 2020-08-12 10:57:58 -07:00
zsmalloc.c mm/zsmalloc.c: fix duplicated words 2020-08-12 10:57:58 -07:00
zswap.c mm/zswap: allow setting default status, compressor and allocator in Kconfig 2020-04-07 10:43:41 -07:00