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charset="utf-8" Reassigning nodes relative an empty user-provided nodemask is useless, and triggers divide-by-zero in the function. Reported-by: Farhad Alemi Link: https://lore.kernel.org/all/CA+0ovCgxbZkXa+OU8w3s84R3KNPNxxRfmsNR-udh= +afQBbGNmw@mail.gmail.com/ Signed-off-by: Yury Norov --- mm/mempolicy.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4e4421b22b59..cd961fa1eb33 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -370,8 +370,13 @@ static inline int mpol_store_user_nodemask(const struc= t mempolicy *pol) static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, const nodemask_t *rel) { + unsigned int w =3D nodes_weight(*rel); nodemask_t tmp; - nodes_fold(tmp, *orig, nodes_weight(*rel)); + + if (w =3D=3D 0) + return -EINVAL; + + nodes_fold(tmp, *orig, w); nodes_onto(*ret, tmp, *rel); } =20 --=20 2.51.0