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Filename Latest commit message Latest commit date
Muchun Song af5508b1e8 mm: hugetlb: fix a race between isolating and freeing page
commit 0eb2df2b5629794020f75e94655e1994af63f0d4 upstream.

There is a race between isolate_huge_page() and __free_huge_page().

  CPU0:                                     CPU1:

  if (PageHuge(page))
                                            put_page(page)
                                              __free_huge_page(page)
                                                  spin_lock(&hugetlb_lock)
                                                  update_and_free_page(page)
                                                    set_compound_page_dtor(page,
                                                      NULL_COMPOUND_DTOR)
                                                  spin_unlock(&hugetlb_lock)
    isolate_huge_page(page)
      // trigger BUG_ON
      VM_BUG_ON_PAGE(!PageHead(page), page)
      spin_lock(&hugetlb_lock)
      page_huge_active(page)
        // trigger BUG_ON
        VM_BUG_ON_PAGE(!PageHuge(page), page)
      spin_unlock(&hugetlb_lock)

When we isolate a HugeTLB page on CPU0.  Meanwhile, we free it to the
buddy allocator on CPU1.  Then, we can trigger a BUG_ON on CPU0, because
it is already freed to the buddy allocator.

Link: https://lkml.kernel.org/r/20210115124942.46403-5-songmuchun@bytedance.com
Fixes: c8721bbbdd ("mm: memory-hotplug: enable memory hotplug to handle hugepage")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:25:31 +01:00
arch ARM: footbridge: fix dc21285 PCI configuration accessors 2021-02-10 09:25:31 +01:00
block Revert "Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"" 2021-02-07 15:35:47 +01:00
certs
crypto crypto: asym_tpm: correct zero out potential secrets 2021-01-12 20:16:17 +01:00
Documentation KVM: Forbid the use of tagged userspace addresses for memslots 2021-02-03 23:25:57 +01:00
drivers nvme-pci: avoid the deepest sleep state on Kingston A2000 SSDs 2021-02-10 09:25:30 +01:00
fs mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page 2021-02-10 09:25:31 +01:00
include mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page 2021-02-10 09:25:31 +01:00
init fgraph: Initialize tracing_graph_pause at task creation 2021-02-10 09:25:29 +01:00
ipc
kernel genirq/msi: Activate Multi-MSI early when MSI_FLAG_ACTIVATE_EARLY is set 2021-02-10 09:25:30 +01:00
lib lib/raid6: Let $(UNROLL) rules work with macOS userland 2021-01-19 18:26:15 +01:00
LICENSES
mm mm: hugetlb: fix a race between isolating and freeing page 2021-02-10 09:25:31 +01:00
net mac80211: fix station rate table updates on assoc 2021-02-10 09:25:29 +01:00
samples samples: bpf: Fix lwt_len_hist reusing previous BPF map 2020-12-30 11:51:12 +01:00
scripts depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-12 20:16:10 +01:00
security dump_common_audit_data(): fix racy accesses to ->d_name 2021-01-19 18:26:16 +01:00
sound ALSA: hda: Add Cometlake-R PCI ID 2021-02-07 15:35:49 +01:00
tools objtool: Don't fail on missing symbol table 2021-02-07 15:35:49 +01:00
usr
virt KVM: Forbid the use of tagged userspace addresses for memslots 2021-02-03 23:25:57 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.96 2021-02-07 15:35:50 +01:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.