linux/mm
Chen Jun bcbda81020 mm: fix uninitialized use in overcommit_policy_handler
We get an unexpected value of /proc/sys/vm/overcommit_memory after
running the following program:

  int main()
  {
      int fd = open("/proc/sys/vm/overcommit_memory", O_RDWR);
      write(fd, "1", 1);
      write(fd, "2", 1);
      close(fd);
  }

write(fd, "2", 1) will pass *ppos = 1 to proc_dointvec_minmax.
proc_dointvec_minmax will return 0 without setting new_policy.

  t.data = &new_policy;
  ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos)
      -->do_proc_dointvec
         -->__do_proc_dointvec
              if (write) {
                if (proc_first_pos_non_zero_ignore(ppos, table))
                  goto out;

  sysctl_overcommit_memory = new_policy;

so sysctl_overcommit_memory will be set to an uninitialized value.

Check whether new_policy has been changed by proc_dointvec_minmax.

Link: https://lkml.kernel.org/r/20210923020524.13289-1-chenjun102@huawei.com
Fixes: 56f3547bfa ("mm: adjust vm_committed_as_batch according to vm overcommit policy")
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-24 16:13:35 -07:00
..
damon mm/damon: don't use strnlen() with known-bogus source length 2021-09-24 16:13:34 -07:00
kasan Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
kfence Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
backing-dev.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
balloon_compaction.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
bootmem_info.c mm/bootmem_info.c: mark __init on register_page_bootmem_info_section 2021-09-03 09:58:14 -07:00
cleancache.c
cma_debug.c mm/cma: change cma mutex to irq safe spinlock 2021-05-05 11:27:21 -07:00
cma_sysfs.c mm: cma: support sysfs 2021-05-05 11:27:24 -07:00
cma.c mm: use proper type for cma_[alloc|release] 2021-05-05 11:27:24 -07:00
cma.h mm: cma: support sysfs 2021-05-05 11:27:24 -07:00
compaction.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: fix corrupted page flag 2021-09-03 09:58:10 -07:00
debug.c mm/debug: sync up latest migrate_reason to migrate_reason_names 2021-09-24 16:13:35 -07:00
dmapool.c mm/dmapool: use DEVICE_ATTR_RO macro 2021-06-29 10:53:52 -07:00
early_ioremap.c mm/early_ioremap.c: remove redundant early_ioremap_shutdown() 2021-09-08 11:50:24 -07:00
fadvise.c
failslab.c
filemap.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
frontswap.c mm/mempool: minor coding style tweaks 2021-05-05 11:27:27 -07:00
gup_test.c selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages 2021-05-05 11:27:26 -07:00
gup_test.h selftests/vm: gup_test: fix test flag 2021-05-05 11:27:26 -07:00
gup.c Revert "mm/gup: remove try_get_page(), call try_get_compound_head() directly" 2021-09-07 11:03:45 -07:00
highmem.c mm: in_irq() cleanup 2021-09-08 11:50:24 -07:00
hmm.c mm/hmm: bypass devmap pte when all pfn requested flags are fulfilled 2021-09-08 18:45:52 -07:00
huge_memory.c mm,do_huge_pmd_numa_page: remove unnecessary TLB flushing code 2021-09-03 09:58:13 -07:00
hugetlb_cgroup.c hugetlb: make free_huge_page irq safe 2021-05-05 11:27:22 -07:00
hugetlb_vmemmap.c mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON 2021-06-30 20:47:26 -07:00
hugetlb_vmemmap.h mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate 2021-06-30 20:47:25 -07:00
hugetlb.c mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY 2021-09-03 09:58:17 -07:00
hwpoison-inject.c mm: hwpoison: don't drop slab caches for offlining non-LRU page 2021-09-03 09:58:15 -07:00
init-mm.c mm: add setup_initial_init_mm() helper 2021-07-08 11:48:21 -07:00
internal.h mm/numa: automatically generate node migration order 2021-09-03 09:58:16 -07:00
interval_tree.c mm/interval_tree: add comments to improve code readability 2021-04-30 11:20:38 -07:00
io-mapping.c mm: add a io_mapping_map_user helper 2021-04-30 11:20:39 -07:00
ioremap.c mm: move ioremap_page_range to vmalloc.c 2021-09-08 11:50:24 -07:00
Kconfig mm/idle_page_tracking: make PG_idle reusable 2021-09-08 11:50:24 -07:00
Kconfig.debug
khugepaged.c huge tmpfs: SGP_NOALLOC to stop collapse_file() on race 2021-09-03 09:58:12 -07:00
kmemleak.c mm/kmemleak: allow __GFP_NOLOCKDEP passed to kmemleak's gfp 2021-09-08 18:45:53 -07:00
ksm.c mm/ksm: remove old GCC 4.9+ check 2021-09-13 10:18:28 -07:00
list_lru.c mm: vmscan: consolidate shrinker_maps handling code 2021-05-05 11:27:23 -07:00
maccess.c ARM: 9115/1: mm/maccess: fix unaligned copy_{from,to}_kernel_nofault 2021-08-20 11:39:25 +01:00
madvise.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
Makefile mm: introduce Data Access MONitor (DAMON) 2021-09-08 11:50:24 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: remove double Note in kerneldoc 2021-07-01 11:06:02 -07:00
memblock.c memblock: introduce saner 'memblock_free_ptr()' interface 2021-09-14 13:23:22 -07:00
memcontrol.c memcg: flush lruvec stats in the refault 2021-09-23 10:09:13 -07:00
memfd.c Reimplement RLIMIT_MEMLOCK on top of ucounts 2021-04-30 14:14:02 -05:00
memory_hotplug.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
memory-failure.c mm/memory_failure: fix the missing pte_unmap() call 2021-09-24 16:13:35 -07:00
memory.c afs: Fix mmap coherency vs 3rd-party changes 2021-09-13 09:10:39 +01:00
mempolicy.c Merge branches 'akpm' and 'akpm-hotfixes' (patches from Andrew) 2021-09-08 18:52:05 -07:00
mempool.c kasan: use separate (un)poison implementation for integrated init 2021-06-04 19:32:21 +01:00
memremap.c mm/memory_hotplug: remove nid parameter from arch_remove_memory() 2021-09-08 11:50:23 -07:00
memtest.c
migrate.c compat: remove some compat entry points 2021-09-08 15:32:35 -07:00
mincore.c inode: make init and permission helpers idmapped mount aware 2021-01-24 14:27:16 +01:00
mlock.c mm: introduce memfd_secret system call to create "secret" memory areas 2021-07-08 11:48:21 -07:00
mm_init.c include/linux/page-flags-layout.h: cleanups 2021-04-30 11:20:42 -07:00
mmap_lock.c mm: mmap_lock: fix disabling preemption directly 2021-07-23 17:43:28 -07:00
mmap.c Merge tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linux 2021-09-04 11:35:47 -07:00
mmu_gather.c mm: eliminate "expecting prototype" kernel-doc warnings 2021-04-16 16:10:36 -07:00
mmu_notifier.c mm/mmu_notifiers: ensure range_end() is paired with range_start() 2021-03-25 09:22:55 -07:00
mmzone.c
mprotect.c mm: device exclusive memory access 2021-07-01 11:06:03 -07:00
mremap.c mm/mremap: fix memory account on do_munmap() failure 2021-09-03 09:58:14 -07:00
msync.c mm/msync: exit early when the flags is an MS_ASYNC and start < vm_start 2021-04-30 11:20:37 -07:00
nommu.c Merge tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linux 2021-09-04 11:35:47 -07:00
oom_kill.c mm: introduce process_mrelease system call 2021-09-03 09:58:17 -07:00
page_alloc.c mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype 2021-09-08 18:45:53 -07:00
page_counter.c mm: page_counter: mitigate consequences of a page_counter underflow 2021-04-30 11:20:38 -07:00
page_ext.c mm/idle_page_tracking: make PG_idle reusable 2021-09-08 11:50:24 -07:00
page_idle.c mm/idle_page_tracking: make PG_idle reusable 2021-09-08 11:50:24 -07:00
page_io.c swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
page_isolation.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
page_owner.c mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE 2021-09-08 11:50:22 -07:00
page_poison.c mm: page_poison: print page info when corruption is caught 2021-04-30 11:20:36 -07:00
page_reporting.c mm/page_reporting: allow driver to specify reporting order 2021-06-29 10:53:47 -07:00
page_reporting.h mm/page_reporting: export reporting order as module parameter 2021-06-29 10:53:47 -07:00
page_vma_mapped.c mm: device exclusive memory access 2021-07-01 11:06:03 -07:00
page-writeback.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
pagewalk.c mm: pagewalk: fix walk for hugepage tables 2021-06-29 10:53:49 -07:00
percpu-internal.h Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu 2021-07-01 17:17:24 -07:00
percpu-km.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu-stats.c percpu: rework memcg accounting 2021-06-05 20:43:15 +00:00
percpu-vm.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
pgalloc-track.h mm: fix typos in comments 2021-05-07 00:26:35 -07:00
pgtable-generic.c mm/thp: fix __split_huge_pmd_locked() on shmem migration entry 2021-06-16 09:24:42 -07:00
process_vm_access.c mm/process_vm_access.c: remove duplicate include 2021-05-05 11:27:27 -07:00
ptdump.c mm: ptdump: fix build failure 2021-04-16 16:10:37 -07:00
readahead.c mm: Protect operations adding pages to page cache with invalidate_lock 2021-07-13 13:14:27 +02:00
rmap.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
rodata_test.c
secretmem.c mm/secretmem: use refcount_t instead of atomic_t 2021-09-08 11:50:24 -07:00
shmem.c mm/shmem.c: fix judgment error in shmem_is_huge() 2021-09-24 16:13:34 -07:00
shuffle.c mm: eliminate "expecting prototype" kernel-doc warnings 2021-04-16 16:10:36 -07:00
shuffle.h mm/shuffle: fix section mismatch warning 2021-05-22 15:09:07 -10:00
slab_common.c mm: slub: move flush_cpu_slab() invocations __free_slab() invocations out of IRQ context 2021-09-04 01:12:23 +02:00
slab.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
slab.h mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook() 2021-07-30 10:14:39 -07:00
slob.c mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernels 2021-03-08 14:18:46 -08:00
slub.c mm, slub: convert kmem_cpu_slab protection to local_lock 2021-09-04 10:22:01 +02:00
sparse-vmemmap.c mm: sparsemem: split the huge PMD mapping of vmemmap pages 2021-06-30 20:47:26 -07:00
sparse.c mm: introduce memmap_alloc() to unify memory map allocation 2021-09-03 09:58:15 -07:00
swap_cgroup.c
swap_slots.c mm: Replace deprecated CPU-hotplug functions. 2021-08-28 01:46:17 +02:00
swap_state.c Revert "mm: swap: check if swap backing device is congested or not" 2021-08-20 11:31:42 -07:00
swap.c mm: fs: invalidate bh_lrus for only cold path 2021-09-24 16:13:35 -07:00
swapfile.c mm, memcg: inline swap-related functions to improve disabled memcg config 2021-09-03 09:58:12 -07:00
truncate.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
usercopy.c
userfaultfd.c userfaultfd: change mmap_changing to atomic 2021-09-03 09:58:16 -07:00
util.c mm: fix uninitialized use in overcommit_policy_handler 2021-09-24 16:13:35 -07:00
vmacache.c
vmalloc.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
vmpressure.c mm/vmpressure: replace vmpressure_to_css() with vmpressure_to_memcg() 2021-09-03 09:58:17 -07:00
vmscan.c mm,vmscan: fix divide by zero in get_scan_count 2021-09-08 18:45:53 -07:00
vmstat.c mm/vmstat: protect per cpu variables with preempt disable on RT 2021-09-08 15:32:34 -07:00
workingset.c memcg: flush lruvec stats in the refault 2021-09-23 10:09:13 -07:00
z3fold.c mm/z3fold: add kerneldoc fields for z3fold_pool 2021-07-01 11:06:03 -07:00
zbud.c mm/zbud: add kerneldoc fields for zbud_pool 2021-07-01 11:06:03 -07:00
zpool.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
zsmalloc.c mm/zsmalloc.c: improve readability for async_free_zspage() 2021-07-01 11:06:02 -07:00
zswap.c mm/zswap.c: fix two bugs in zswap_writeback_entry() 2021-06-30 20:47:31 -07:00