mm/mempolicy.c: avoid use uninitialized preferred_node
authorYisheng Xie <xieyisheng1@huawei.com>
Thu, 22 Mar 2018 23:17:02 +0000 (16:17 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 30 May 2018 05:52:19 +0000 (07:52 +0200)
commit6ca473201d709e2d061bf770776b96b9024e58df
tree426ff166c0b2c5f51be33bd2df2e8b62ce099bdc
parent5498a2b5795f45de39dc1508a7e5aa1da7ba3447
mm/mempolicy.c: avoid use uninitialized preferred_node

[ Upstream commit 8970a63e965b43288c4f5f40efbc2bbf80de7f16 ]

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.

[akpm@linux-foundation.org: slight comment tweak]
Link: http://lkml.kernel.org/r/4ebee1c2-57f6-bcb8-0e2d-1833d1ee0bb7@huawei.com
Fixes: fc36b8d3d819 ("mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy")
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/mempolicy.c