Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
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From: Aneesh Kumar K.V <hidden>
Date: 2022-12-15 13:57:56
Also in:
lkml, stable
Mathieu Desnoyers [off-list ref] writes:
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.
Reviewed-by: Aneesh Kumar K.V <redacted>
quoted hunk ↗ jump to hunk
Fixes: c6018b4b2549 ("mm/mempolicy: add set_mempolicy_home_node syscall") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Aneesh Kumar K.V <redacted> Cc: Ben Widawsky <redacted> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Feng Tang <redacted> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <redacted> Cc: Mel Gorman <redacted> Cc: Mike Kravetz <redacted> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <redacted> Cc: Andi Kleen <redacted> Cc: Dan Williams <redacted> Cc: Huang Ying <redacted> Cc: <redacted> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org # 5.17+ --- 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; }-- 2.25.1