3.2.102-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Yisheng Xie <xieyishe...@huawei.com> commit 8970a63e965b43288c4f5f40efbc2bbf80de7f16 upstream. Alexander reported a use of uninitialized memory in __mpol_equal(), which is caused by incorrect use of preferred_node. When mempolicy in mode MPOL_PREFERRED with flags MPOL_F_LOCAL, it uses numa_node_id() instead of preferred_node, however, __mpol_equal() uses preferred_node without checking whether it is MPOL_F_LOCAL or not. [a...@linux-foundation.org: slight comment tweak] Link: http://lkml.kernel.org/r/4ebee1c2-57f6-bcb8-0e2d-1833d1ee0...@huawei.com Fixes: fc36b8d3d819 ("mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy") Signed-off-by: Yisheng Xie <xieyishe...@huawei.com> Reported-by: Alexander Potapenko <gli...@google.com> Tested-by: Alexander Potapenko <gli...@google.com> Reviewed-by: Andrew Morton <a...@linux-foundation.org> Cc: Dmitriy Vyukov <dvyu...@google.com> Cc: Vlastimil Babka <vba...@suse.cz> Cc: Michal Hocko <mho...@kernel.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- mm/mempolicy.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2019,6 +2019,9 @@ int __mpol_equal(struct mempolicy *a, st case MPOL_INTERLEAVE: return nodes_equal(a->v.nodes, b->v.nodes); case MPOL_PREFERRED: + /* a's ->flags is the same as b's */ + if (a->flags & MPOL_F_LOCAL) + return true; return a->v.preferred_node == b->v.preferred_node; default: BUG();
