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| author |   Matthew Wilcox <mawilcox@microsoft.com> | 2018-04-20 14:56:20 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-20 17:18:36 -0700 |
| commit | abc1be13fd113ddef5e2d807a466286b864caed3 (patch) | |
| tree | 7991dabeeb9923fb7b055fd6b092463f5ef8e994 /mm/pgtable-generic.c | |
| parent | mm: memcg: add __GFP_NOWARN in __memcg_schedule_kmem_cache_create() (diff) | |
| download | wireguard-linux-abc1be13fd113ddef5e2d807a466286b864caed3.tar.xz wireguard-linux-abc1be13fd113ddef5e2d807a466286b864caed3.zip | |
mm/filemap.c: fix NULL pointer in page_cache_tree_insert()
f2fs specifies the __GFP_ZERO flag for allocating some of its pages.
Unfortunately, the page cache also uses the mapping's GFP flags for
allocating radix tree nodes. It always masked off the __GFP_HIGHMEM
flag, and masks off __GFP_ZERO in some paths, but not all. That causes
radix tree nodes to be allocated with a NULL list_head, which causes
backtraces like:
__list_del_entry+0x30/0xd0
list_lru_del+0xac/0x1ac
page_cache_tree_insert+0xd8/0x110
The __GFP_DMA and __GFP_DMA32 flags would also be able to sneak through
if they are ever used. Fix them all by using GFP_RECLAIM_MASK at the
innermost location, and remove it from earlier in the callchain.
Link: http://lkml.kernel.org/r/20180411060320.14458-2-willy@infradead.org
Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check")
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reported-by: Chris Fries <cfries@google.com>
Debugged-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/pgtable-generic.c')
0 files changed, 0 insertions, 0 deletions