[PATCH 6.1 45/71] mm/mempolicy: fix memory leak in set_mempolicy_home_node system call

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>

commit 38ce7c9bdfc228c14d7621ba36d3eebedd9d4f76 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 mm/mempolicy.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/mempolicy.c
+++ b/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;
 		}





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux