diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2021-01-23 21:01:52 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-30 16:23:19 +0200 |
| commit | 406166a3acd7b5cac029050f216c5ac3d4d5004d (patch) | |
| tree | ded1732fc66bf5c42e7cf1f5be258d1b47e12077 | |
| parent | 749630ce9147834a87dbf4e253f26c8f2f325b2e (diff) | |
mm: fix page reference leak in soft_offline_page()
[ Upstream commit dad4e5b390866ca902653df0daa864ae4b8d4147 ]
The conversion to move pfn_to_online_page() internal to
soft_offline_page() missed that the get_user_pages() reference taken by
the madvise() path needs to be dropped when pfn_to_online_page() fails.
Note the direct sysfs-path to soft_offline_page() does not perform a
get_user_pages() lookup.
When soft_offline_page() is handed a pfn_valid() && !pfn_to_online_page()
pfn the kernel hangs at dax-device shutdown due to a leaked reference.
Link: https://lkml.kernel.org/r/161058501210.1840162.8108917599181157327.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: feec24a6139d ("mm, soft-offline: convert parameter to pfn")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: e2c1ab070fdc ("mm: memory-failure: fix unexpected return value in soft_offline_page()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | mm/memory-failure.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 71fd546dbdc3..e3c0fa2464ff 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1867,6 +1867,12 @@ static int soft_offline_free_page(struct page *page) return rc; } +static void put_ref_page(struct page *page) +{ + if (page) + put_page(page); +} + /** * soft_offline_page - Soft offline a page. * @pfn: pfn to soft-offline @@ -1892,20 +1898,26 @@ static int soft_offline_free_page(struct page *page) int soft_offline_page(unsigned long pfn, int flags) { int ret; - struct page *page; bool try_again = true; + struct page *page, *ref_page = NULL; + + WARN_ON_ONCE(!pfn_valid(pfn) && (flags & MF_COUNT_INCREASED)); if (!pfn_valid(pfn)) return -ENXIO; + if (flags & MF_COUNT_INCREASED) + ref_page = pfn_to_page(pfn); + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ page = pfn_to_online_page(pfn); - if (!page) + if (!page) { + put_ref_page(ref_page); return -EIO; + } if (PageHWPoison(page)) { pr_info("%s: %#lx page already poisoned\n", __func__, pfn); - if (flags & MF_COUNT_INCREASED) - put_page(page); + put_ref_page(ref_page); return 0; } |