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| author | Matthew Wilcox <willy@infradead.org> | 2018-11-27 13:16:33 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-17 09:24:41 +0100 |
| commit | 384f18115267c0e52748137d6720c81b1cf220e1 (patch) | |
| tree | e53a5f6da9edd113e80328e544e7e064f8e6bbf2 /fs/dax.c | |
| parent | 111758f73595528e4f9f51b54cca27470d130e08 (diff) | |
| download | linux-rt-384f18115267c0e52748137d6720c81b1cf220e1.tar.gz | |
dax: Check page->mapping isn't NULL
commit c93db7bb6ef3251e0ea48ade311d3e9942748e1c upstream.
If we race with inode destroy, it's possible for page->mapping to be
NULL before we even enter this routine, as well as after having slept
waiting for the dax entry to become unlocked.
Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()")
Cc: <stable@vger.kernel.org>
Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/dax.c')
| -rw-r--r-- | fs/dax.c | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -423,7 +423,7 @@ bool dax_lock_mapping_entry(struct page *page) for (;;) { mapping = READ_ONCE(page->mapping); - if (!dax_mapping(mapping)) + if (!mapping || !dax_mapping(mapping)) break; /* |