https://github.com/torvalds/linux
Revision 7ffddd499ba6122b1a07828f023d1d67629aa017 authored by Muchun Song on 05 February 2021, 02:32:06 UTC, committed by Linus Torvalds on 05 February 2021, 19:03:47 UTC
There is a race condition between __free_huge_page() and dissolve_free_huge_page(). CPU0: CPU1: // page_count(page) == 1 put_page(page) __free_huge_page(page) dissolve_free_huge_page(page) spin_lock(&hugetlb_lock) // PageHuge(page) && !page_count(page) update_and_free_page(page) // page is freed to the buddy spin_unlock(&hugetlb_lock) spin_lock(&hugetlb_lock) clear_page_huge_active(page) enqueue_huge_page(page) // It is wrong, the page is already freed spin_unlock(&hugetlb_lock) The race window is between put_page() and dissolve_free_huge_page(). We should make sure that the page is already on the free list when it is dissolved. As a result __free_huge_page would corrupt page(s) already in the buddy allocator. Link: https://lkml.kernel.org/r/20210115124942.46403-4-songmuchun@bytedance.com Fixes: c8721bbbdd36 ("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> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> 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>
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Tip revision: 7ffddd499ba6122b1a07828f023d1d67629aa017 authored by Muchun Song on 05 February 2021, 02:32:06 UTC
mm: hugetlb: fix a race between freeing and dissolving the page
mm: hugetlb: fix a race between freeing and dissolving the page
Tip revision: 7ffddd4
File | Mode | Size |
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accounting | ||
arch | ||
bootconfig | ||
bpf | ||
build | ||
cgroup | ||
debugging | ||
edid | ||
firewire | ||
firmware | ||
gpio | ||
hv | ||
iio | ||
include | ||
io_uring | ||
kvm | ||
laptop | ||
leds | ||
lib | ||
memory-model | ||
objtool | ||
pci | ||
pcmcia | ||
perf | ||
power | ||
scripts | ||
spi | ||
testing | ||
thermal | ||
time | ||
usb | ||
virtio | ||
vm | ||
wmi | ||
Makefile | -rw-r--r-- | 6.1 KB |
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