Messages in this thread | | | Date | Wed, 14 Dec 2022 15:16:22 -0800 | Subject | Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call | From | Randy Dunlap <> |
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On 12/14/22 14:21, Mathieu Desnoyers wrote: > 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. > > Fixes: c6018b4b2549 ("mm/mempolicy: add set_mempolicy_home_node syscall") > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > Cc: Ben Widawsky <ben.widawsky@intel.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: <linux-api@vger.kernel.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: stable@vger.kernel.org # 5.17+
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Thanks.
> --- > mm/mempolicy.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 61aa9aedb728..02c8a712282f 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -1540,6 +1540,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le > * 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; > }
-- ~Randy
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