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...

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@efficios.com 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@efficios... Fixes: c6018b4b2549 ("mm/mempolicy: add set_mempolicy_home_node syscall") Signed-off-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com Reviewed-by: Randy Dunlap rdunlap@infradead.org Reviewed-by: "Huang, Ying" ying.huang@intel.com Reviewed-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Acked-by: Michal Hocko mhocko@suse.com Cc: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Feng Tang feng.tang@intel.com Cc: Michal Hocko mhocko@kernel.org Cc: Andrea Arcangeli aarcange@redhat.com Cc: Mel Gorman mgorman@techsingularity.net Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Randy Dunlap rdunlap@infradead.org Cc: Vlastimil Babka vbabka@suse.cz Cc: Andi Kleen ak@linux.intel.com Cc: Dan Williams dan.j.williams@intel.com Cc: Huang Ying ying.huang@intel.com Cc: stable@vger.kernel.org [5.17+] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

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@efficios.com are

mm-mempolicy-fix-memory-leak-in-set_mempolicy_home_node-system-call.patch