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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-11-05 23:37:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:17:16 +0300 |
| commit | 6560e8cd869b643f674d8fa3ae9243af1d8ba29a (patch) | |
| tree | b7d1fbe24b4b6497e4cad4ed14b643de99552ab9 /mm | |
| parent | 6847c42862972538de4b002de5e82945743d6e35 (diff) | |
| download | linux-6560e8cd869b643f674d8fa3ae9243af1d8ba29a.tar.xz | |
mm/filemap.c: remove bogus VM_BUG_ON
commit d417b49fff3e2f21043c834841e8623a6098741d upstream.
It is not safe to check page->index without holding the page lock. It
can be changed if the page is moved between the swap cache and the page
cache for a shmem file, for example. There is a VM_BUG_ON below which
checks page->index is correct after taking the page lock.
Link: https://lkml.kernel.org/r/20210818144932.940640-1-willy@infradead.org
Fixes: 5c211ba29deb ("mm: add and use find_lock_entries")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: <syzbot+c87be4f669d920c76330@syzkaller.appspotmail.com>
Cc: Hugh Dickins <hughd@google.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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/filemap.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index dae481293b5d..82a17c35eb96 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2093,7 +2093,6 @@ unsigned find_lock_entries(struct address_space *mapping, pgoff_t start, if (!xa_is_value(page)) { if (page->index < start) goto put; - VM_BUG_ON_PAGE(page->index != xas.xa_index, page); if (page->index + thp_nr_pages(page) - 1 > end) goto put; if (!trylock_page(page)) |