The patch titled
Subject: mm/mempolicy: fix memory leak in set_mempolicy_home_node system call
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-mempolicy-fix-memory-leak-in-set_mempolicy_home_node-system-call.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mempolicy-fix-memory-leak-in-set_mempolicy_home_node-system-call.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Subject: mm/mempolicy: fix memory leak in set_mempolicy_home_node system call
Date: Thu, 15 Dec 2022 14:46:21 -0500
When encountering any vma in the range with policy other than MPOL_BIND or
MPOL_PREFERRED_MANY, an error is returned without issuing a mpol_put on
the policy just allocated with mpol_dup().
This allows arbitrary users to leak kernel memory.
Link: https://lkml.kernel.org/r/20221215194621.202816-1-mathieu.desnoyers@xxxxxxxxxxxx
Fixes: c6018b4b2549 ("mm/mempolicy: add set_mempolicy_home_node syscall")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Feng Tang <feng.tang@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [5.17+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/mempolicy.c~mm-mempolicy-fix-memory-leak-in-set_mempolicy_home_node-system-call
+++ a/mm/mempolicy.c
@@ -1540,6 +1540,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node,
* the home node for vmas we already updated before.
*/
if (new->mode != MPOL_BIND && new->mode != MPOL_PREFERRED_MANY) {
+ mpol_put(new);
err = -EOPNOTSUPP;
break;
}
_
Patches currently in -mm which might be from mathieu.desnoyers@xxxxxxxxxxxx are
mm-mempolicy-fix-memory-leak-in-set_mempolicy_home_node-system-call.patch
