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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2022-12-15 20:46:21 +0100
committerAndrew Morton <akpm@linux-foundation.org>2022-12-21 23:31:51 +0100
commit38ce7c9bdfc228c14d7621ba36d3eebedd9d4f76 (patch)
tree698c4511f0ca0cfd5168a0b55052d2d5a252ef7c
parentmm, mremap: fix mremap() expanding vma with addr inside vma (diff)
downloadlinux-38ce7c9bdfc228c14d7621ba36d3eebedd9d4f76.tar.xz
linux-38ce7c9bdfc228c14d7621ba36d3eebedd9d4f76.zip
mm/mempolicy: fix memory leak in set_mempolicy_home_node system call
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.com 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>
-rw-r--r--mm/mempolicy.c1
1 files changed, 1 insertions, 0 deletions
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;
}