Jan Kara ebdf4de564 mm: migrate: fix reference check race between __find_get_block() and migration ... buffer_migrate_page_norefs() can race with bh users in the following way: CPU1 CPU2 buffer_migrate_page_norefs() buffer_migrate_lock_buffers() checks bh refs spin_unlock(&mapping->private_lock) __find_get_block() spin_lock(&mapping->private_lock) grab bh ref spin_unlock(&mapping->private_lock) move page do bh work This can result in various issues like lost updates to buffers (i.e. metadata corruption) or use after free issues for the old page. This patch closes the race by holding mapping->private_lock while the mapping is being moved to a new page. Ordinarily, a reference can be taken outside of the private_lock using the per-cpu BH LRU but the references are checked and the LRU invalidated if necessary. The private_lock is held once the references are known so the buffer lookup slow path will spin on the private_lock. Between the page lock and private_lock, it should be impossible for other references to be acquired and updates to happen during the migration. A user had reported data corruption issues on a distribution kernel with a similar page migration implementation as mainline. The data corruption could not be reproduced with this patch applied. A small number of migration-intensive tests were run and no performance problems were noted. [mgorman@techsingularity.net: Changelog, removed tracing] Link: http://lkml.kernel.org/r/20190718090238.GF24383@techsingularity.net Fixes: 89cb0888ca "mm: migrate: provide buffer_migrate_page_norefs()" Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> [5.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2019-08-03 07:02:00 -07:00
..
kasan	mm/kasan: change kasan_check_{read,write} to return boolean	2019-07-12 11:05:42 -07:00
backing-dev.c	backing-dev: no need to check return value of debugfs_create functions	2019-06-03 15:49:07 +02:00
balloon_compaction.c	balloon: fix up comments	2019-07-22 11:19:26 -04:00
cleancache.c	Driver Core and debugfs changes for 5.3-rc1	2019-07-12 12:24:03 -07:00
cma_debug.c	mm/cma_debug.c: fix the break condition in cma_maxchunk_get()	2019-05-14 09:47:45 -07:00
cma.c	mm/cma.c: fail if fixed declaration can't be honored	2019-07-16 19:23:21 -07:00
cma.h
compaction.c	mm, compaction: make sure we isolate a valid PFN	2019-06-01 15:51:32 -07:00
debug_page_ref.c
debug.c	mm: update references to page _refcount	2019-05-14 19:52:47 -07:00
dmapool.c	mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options	2019-07-12 11:05:46 -07:00
early_ioremap.c	mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep	2017-12-11 14:54:44 +01:00
fadvise.c	vfs: implement readahead(2) using POSIX_FADV_WILLNEED	2018-08-30 20:01:32 +02:00
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/filemap.c: correct the comment about VM_FAULT_RETRY	2019-07-12 11:05:43 -07:00
frame_vector.c	mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()'	2017-12-14 16:00:48 -08:00
frontswap.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482	2019-06-19 17:09:52 +02:00
gup_benchmark.c	mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM	2019-05-14 09:47:45 -07:00
gup.c	mm: introduce ARCH_HAS_PTE_DEVMAP	2019-07-16 19:23:25 -07:00
highmem.c	mm: convert totalram_pages and totalhigh_pages variables to atomic	2018-12-28 12:11:47 -08:00
hmm.c	mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot}	2019-07-25 16:14:39 -03:00
huge_memory.c	mm: thp: fix false negative of shmem vma's THP eligibility	2019-07-18 17:08:06 -07:00
hugetlb_cgroup.c	mm: rename page_counter's count/limit into usage/max	2018-06-07 17:34:35 -07:00
hugetlb.c	mm: hugetlb: soft-offline: dissolve_free_huge_page() return zero on !PageHuge	2019-06-29 16:43:45 +08:00
hwpoison-inject.c	hwpoison-inject: no need to check return value of debugfs_create functions	2019-06-03 15:39:40 +02:00
init-mm.c	mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids	2018-07-17 09:35:30 +02:00
internal.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
interval_tree.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248	2019-06-19 17:09:08 +02:00
Kconfig	mm: introduce ARCH_HAS_PTE_DEVMAP	2019-07-16 19:23:25 -07:00
Kconfig.debug	mm, debug_pagealloc: use a page type instead of page_ext flag	2019-07-12 11:05:43 -07:00
khugepaged.c	Revert "mm: page cache: store only head pages in i_pages"	2019-07-05 19:55:18 -07:00
kmemleak-test.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333	2019-06-05 17:37:06 +02:00
kmemleak.c	Revert "kmemleak: allow to coexist with fault injection"	2019-08-03 07:02:00 -07:00
ksm.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482	2019-06-19 17:09:52 +02:00
list_lru.c	mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages	2019-07-12 11:05:44 -07:00
maccess.c	The main changes in this release include:	2019-07-18 11:51:00 -07:00
madvise.c	mm: remove MEMORY_DEVICE_PUBLIC support	2019-07-02 14:32:43 -03:00
Makefile	HMM patches for 5.3	2019-07-14 19:42:11 -07:00
memblock.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
memcontrol.c	mm/memcontrol.c: keep local VM counters in sync with the hierarchical ones	2019-07-16 19:23:21 -07:00
memfd.c	Revert "mm: page cache: store only head pages in i_pages"	2019-07-05 19:55:18 -07:00
memory_hotplug.c	mm/sparsemem: cleanup 'section number' data types	2019-07-18 17:08:07 -07:00
memory-failure.c	HMM patches for 5.3	2019-07-14 19:42:11 -07:00
memory.c	mm: thp: make transhuge_vma_suitable available for anonymous THP	2019-07-18 17:08:06 -07:00
mempolicy.c	mm: export alloc_pages_vma	2019-07-02 14:32:44 -03:00
mempool.c	docs/core-api/mm: fix return value descriptions in mm/	2019-03-05 21:07:20 -08:00
memtest.c
migrate.c	mm: migrate: fix reference check race between __find_get_block() and migration	2019-08-03 07:02:00 -07:00
mincore.c	mm/mincore.c: fix race between swapoff and mincore	2019-07-12 11:05:43 -07:00
mlock.c	mm/mlock.c: change count_mm_mlocked_page_nr return type	2019-06-13 17:34:56 -10:00
mm_init.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
mmap.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
mmu_context.c
mmu_gather.c	mm: mmu_gather: remove __tlb_reset_range() for force flush	2019-06-13 17:34:56 -10:00
mmu_notifier.c	mm/mmu_notifier: use hlist_add_head_rcu()	2019-07-12 11:05:46 -07:00
mmzone.c
mprotect.c	mm/mprotect.c: fix compilation warning because of unused 'mm' variable	2019-05-14 09:47:51 -07:00
mremap.c	mm/mmu_notifier: contextual information for event triggering invalidation	2019-05-14 09:47:49 -07:00
msync.c
nommu.c	mm: fix the MAP_UNINITIALIZED flag	2019-07-16 19:23:21 -07:00
oom_kill.c	mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()	2019-07-12 11:05:47 -07:00
page_alloc.c	mm/sparsemem: support sub-section hotplug	2019-07-18 17:08:07 -07:00
page_counter.c	memcg: introduce memory.min	2018-06-07 17:34:36 -07:00
page_ext.c	mm, debug_pagealloc: use a page type instead of page_ext flag	2019-07-12 11:05:43 -07:00
page_idle.c	mm/page_idle.c: fix oops because end_pfn is larger than max_pfn	2019-06-29 16:43:45 +08:00
page_io.c	mm, swap: use rbtree for swap_extent	2019-07-12 11:05:43 -07:00
page_isolation.c	mm/page_isolation.c: change the prototype of undo_isolate_page_range()	2019-07-12 11:05:43 -07:00
page_owner.c	mm/page_owner: Simplify stack trace handling	2019-04-29 12:37:50 +02:00
page_poison.c	page_poison: play nicely with KASAN	2019-03-05 21:07:13 -08:00
page_vma_mapped.c	mm/rmap: map_pte() was not handling private ZONE_DEVICE page properly	2018-10-31 08:54:11 -07:00
page-writeback.c	mm: remove the account_page_dirtied export	2019-07-12 11:05:42 -07:00
pagewalk.c	mm: kernel-doc: add missing parameter descriptions	2018-04-05 21:36:27 -07:00
percpu-internal.h	percpu: convert chunk hints to be based on pcpu_block_md	2019-03-13 12:25:31 -07:00
percpu-km.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
percpu-stats.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
percpu-vm.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
percpu.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
pgtable-generic.c	x86/mm: Page size aware flush_tlb_mm_range()	2018-10-09 16:51:11 +02:00
process_vm_access.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
quicklist.c
readahead.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
rmap.c	mm/rmap.c: use the pra.mapcount to do the check	2019-05-14 09:47:49 -07:00
rodata_test.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
shmem.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
shuffle.c	mm: maintain randomization of page free lists	2019-05-14 19:52:48 -07:00
shuffle.h	mm: maintain randomization of page free lists	2019-05-14 19:52:48 -07:00
slab_common.c	mm/slab_common.c: work around clang bug #42570	2019-07-16 19:23:21 -07:00
slab.c	mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options	2019-07-12 11:05:46 -07:00
slab.h	mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options	2019-07-12 11:05:46 -07:00
slob.c	mm/slab: refactor common ksize KASAN logic into slab_common.c	2019-07-12 11:05:42 -07:00
slub.c	mm: slub: Fix slab walking for init_on_free	2019-07-31 13:16:06 -07:00
sparse-vmemmap.c	mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()	2019-07-18 17:08:07 -07:00
sparse.c	mm/sparsemem: cleanup 'section number' data types	2019-07-18 17:08:07 -07:00
swap_cgroup.c
swap_slots.c	mm, swap, get_swap_pages: use entry_size instead of cluster in parameter	2018-08-22 10:52:44 -07:00
swap_state.c	mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device()	2019-07-12 11:05:43 -07:00
swap.c	docs: admin-guide: move sysctl directory to it	2019-07-15 11:03:01 -03:00
swapfile.c	mm, swap: use rbtree for swap_extent	2019-07-12 11:05:43 -07:00
truncate.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
usercopy.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
userfaultfd.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499	2019-06-19 17:09:53 +02:00
util.c	mm: add account_locked_vm utility function	2019-07-16 19:23:25 -07:00
vmacache.c	mm: get rid of vmacache_flush_all() entirely	2018-09-13 15:18:04 -10:00
vmalloc.c	mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()	2019-07-22 10:18:30 +02:00
vmpressure.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
vmscan.c	mm: vmscan: check if mem cgroup is disabled or not before calling memcg slab shrinker	2019-08-03 07:02:00 -07:00
vmstat.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
workingset.c	mm: memcontrol: make cgroup stats and events query API explicitly local	2019-05-14 19:52:53 -07:00
z3fold.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
zbud.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
zpool.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
zsmalloc.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
zswap.c	zswap: ignore debugfs_create_dir() return value	2019-06-03 15:39:39 +02:00