* [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
@ 2022-12-14 22:21 Mathieu Desnoyers
2022-12-14 23:16 ` Randy Dunlap
` (3 more replies)
0 siblings, 4 replies; 9+ messages in thread
From: Mathieu Desnoyers @ 2022-12-14 22:21 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-kernel, Mathieu Desnoyers, Aneesh Kumar K . V,
Ben Widawsky, Dave Hansen, Feng Tang, Michal Hocko,
Andrea Arcangeli, Mel Gorman, Mike Kravetz, Randy Dunlap,
Vlastimil Babka, Andi Kleen, Dan Williams, Huang Ying, linux-api,
stable
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+
---
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
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
2022-12-14 22:21 [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Mathieu Desnoyers
@ 2022-12-14 23:16 ` Randy Dunlap
2022-12-15 6:34 ` Huang, Ying
` (2 subsequent siblings)
3 siblings, 0 replies; 9+ messages in thread
From: Randy Dunlap @ 2022-12-14 23:16 UTC (permalink / raw)
To: Mathieu Desnoyers, Andrew Morton
Cc: linux-kernel, Aneesh Kumar K . V, Ben Widawsky, Dave Hansen,
Feng Tang, Michal Hocko, Andrea Arcangeli, Mel Gorman,
Mike Kravetz, Vlastimil Babka, Andi Kleen, Dan Williams,
Huang Ying, linux-api, stable
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
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
2022-12-14 22:21 [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Mathieu Desnoyers
2022-12-14 23:16 ` Randy Dunlap
@ 2022-12-15 6:34 ` Huang, Ying
2022-12-15 7:51 ` Michal Hocko
2022-12-15 13:56 ` [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Aneesh Kumar K.V
3 siblings, 0 replies; 9+ messages in thread
From: Huang, Ying @ 2022-12-15 6:34 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: Andrew Morton, linux-kernel, Aneesh Kumar K . V, Ben Widawsky,
Dave Hansen, Feng Tang, Michal Hocko, Andrea Arcangeli,
Mel Gorman, Mike Kravetz, Randy Dunlap, Vlastimil Babka,
Andi Kleen, Dan Williams, linux-api, stable
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> 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.
>
> 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: "Huang, Ying" <ying.huang@intel.com>
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;
> }
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
2022-12-14 22:21 [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Mathieu Desnoyers
2022-12-14 23:16 ` Randy Dunlap
2022-12-15 6:34 ` Huang, Ying
@ 2022-12-15 7:51 ` Michal Hocko
2022-12-15 13:57 ` Aneesh Kumar K.V
2022-12-15 14:33 ` Mathieu Desnoyers
2022-12-15 13:56 ` [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Aneesh Kumar K.V
3 siblings, 2 replies; 9+ messages in thread
From: Michal Hocko @ 2022-12-15 7:51 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: Andrew Morton, linux-kernel, Aneesh Kumar K . V, Ben Widawsky,
Dave Hansen, Feng Tang, Andrea Arcangeli, Mel Gorman,
Mike Kravetz, Randy Dunlap, Vlastimil Babka, Andi Kleen,
Dan Williams, Huang Ying, linux-api, stable
On Wed 14-12-22 17:21:10, 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+
Acked-by: Michal Hocko <mhocko@suse.com>
Thanks for catching this!
Btw. looking at the code again it seems rather pointless to duplicate
the policy just to throw it away anyway. A slightly bigger diff but this
looks more reasonable to me. What do you think? I can also send it as a
clean up on top of your fix.
---
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 61aa9aedb728..918cdc8a7f0c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1489,7 +1489,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- struct mempolicy *new;
+ struct mempolicy *new. *old;
unsigned long vmstart;
unsigned long vmend;
unsigned long end;
@@ -1521,30 +1521,28 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
return 0;
mmap_write_lock(mm);
for_each_vma_range(vmi, vma, end) {
- vmstart = max(start, vma->vm_start);
- vmend = min(end, vma->vm_end);
- new = mpol_dup(vma_policy(vma));
- if (IS_ERR(new)) {
- err = PTR_ERR(new);
- break;
- }
- /*
- * Only update home node if there is an existing vma policy
- */
- if (!new)
- continue;
-
/*
* If any vma in the range got policy other than MPOL_BIND
* or MPOL_PREFERRED_MANY we return error. We don't reset
* the home node for vmas we already updated before.
*/
- if (new->mode != MPOL_BIND && new->mode != MPOL_PREFERRED_MANY) {
+ old = vma_policy(vma);
+ if (!old)
+ continue;
+ if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) {
err = -EOPNOTSUPP;
break;
}
+ new = mpol_dup(vma_policy(vma));
+ if (IS_ERR(new)) {
+ err = PTR_ERR(new);
+ break;
+ }
+
new->home_node = home_node;
+ vmstart = max(start, vma->vm_start);
+ vmend = min(end, vma->vm_end);
err = mbind_range(mm, vmstart, vmend, new);
mpol_put(new);
if (err)
--
Michal Hocko
SUSE Labs
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
2022-12-14 22:21 [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Mathieu Desnoyers
` (2 preceding siblings ...)
2022-12-15 7:51 ` Michal Hocko
@ 2022-12-15 13:56 ` Aneesh Kumar K.V
3 siblings, 0 replies; 9+ messages in thread
From: Aneesh Kumar K.V @ 2022-12-15 13:56 UTC (permalink / raw)
To: Mathieu Desnoyers, Andrew Morton
Cc: linux-kernel, Mathieu Desnoyers, Ben Widawsky, Dave Hansen,
Feng Tang, Michal Hocko, Andrea Arcangeli, Mel Gorman,
Mike Kravetz, Randy Dunlap, Vlastimil Babka, Andi Kleen,
Dan Williams, Huang Ying, linux-api, stable
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> 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 <aneesh.kumar@linux.ibm.com>
> 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+
> ---
> 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
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
2022-12-15 7:51 ` Michal Hocko
@ 2022-12-15 13:57 ` Aneesh Kumar K.V
2022-12-15 14:33 ` Mathieu Desnoyers
1 sibling, 0 replies; 9+ messages in thread
From: Aneesh Kumar K.V @ 2022-12-15 13:57 UTC (permalink / raw)
To: Michal Hocko, Mathieu Desnoyers
Cc: Andrew Morton, linux-kernel, Ben Widawsky, Dave Hansen,
Feng Tang, Andrea Arcangeli, Mel Gorman, Mike Kravetz,
Randy Dunlap, Vlastimil Babka, Andi Kleen, Dan Williams,
Huang Ying, linux-api, stable
Michal Hocko <mhocko@suse.com> writes:
> On Wed 14-12-22 17:21:10, 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+
>
> Acked-by: Michal Hocko <mhocko@suse.com>
> Thanks for catching this!
>
> Btw. looking at the code again it seems rather pointless to duplicate
> the policy just to throw it away anyway. A slightly bigger diff but this
> looks more reasonable to me. What do you think? I can also send it as a
> clean up on top of your fix.
> ---
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 61aa9aedb728..918cdc8a7f0c 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1489,7 +1489,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> - struct mempolicy *new;
> + struct mempolicy *new. *old;
> unsigned long vmstart;
> unsigned long vmend;
> unsigned long end;
> @@ -1521,30 +1521,28 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
> return 0;
> mmap_write_lock(mm);
> for_each_vma_range(vmi, vma, end) {
> - vmstart = max(start, vma->vm_start);
> - vmend = min(end, vma->vm_end);
> - new = mpol_dup(vma_policy(vma));
> - if (IS_ERR(new)) {
> - err = PTR_ERR(new);
> - break;
> - }
> - /*
> - * Only update home node if there is an existing vma policy
> - */
> - if (!new)
> - continue;
> -
> /*
> * If any vma in the range got policy other than MPOL_BIND
> * or MPOL_PREFERRED_MANY we return error. We don't reset
> * the home node for vmas we already updated before.
> */
> - if (new->mode != MPOL_BIND && new->mode != MPOL_PREFERRED_MANY) {
> + old = vma_policy(vma);
> + if (!old)
> + continue;
> + if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) {
> err = -EOPNOTSUPP;
> break;
> }
>
> + new = mpol_dup(vma_policy(vma));
new = mpol_dup(old);
> + if (IS_ERR(new)) {
> + err = PTR_ERR(new);
> + break;
> + }
> +
> new->home_node = home_node;
> + vmstart = max(start, vma->vm_start);
> + vmend = min(end, vma->vm_end);
> err = mbind_range(mm, vmstart, vmend, new);
> mpol_put(new);
> if (err)
> --
> Michal Hocko
> SUSE Labs
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call
2022-12-15 7:51 ` Michal Hocko
2022-12-15 13:57 ` Aneesh Kumar K.V
@ 2022-12-15 14:33 ` Mathieu Desnoyers
2022-12-15 14:49 ` [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable for set_mempolicy_home_node Michal Hocko
1 sibling, 1 reply; 9+ messages in thread
From: Mathieu Desnoyers @ 2022-12-15 14:33 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, linux-kernel, Aneesh Kumar K . V, Ben Widawsky,
Dave Hansen, Feng Tang, Andrea Arcangeli, Mel Gorman,
Mike Kravetz, Randy Dunlap, Vlastimil Babka, Andi Kleen,
Dan Williams, Huang Ying, linux-api, stable
On 2022-12-15 02:51, Michal Hocko wrote:
> On Wed 14-12-22 17:21:10, 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+
>
> Acked-by: Michal Hocko <mhocko@suse.com>
> Thanks for catching this!
>
> Btw. looking at the code again it seems rather pointless to duplicate
> the policy just to throw it away anyway. A slightly bigger diff but this
> looks more reasonable to me. What do you think? I can also send it as a
> clean up on top of your fix.
I think it would be best if this comes as a cleanup on top of my fix.
The diff is larger than the minimal change needed to fix the leak in
stable branches.
Your approach looks fine, except for the vma_policy(vma) -> old change
already spotted by Aneesh.
Thanks,
Mathieu
> ---
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 61aa9aedb728..918cdc8a7f0c 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1489,7 +1489,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> - struct mempolicy *new;
> + struct mempolicy *new. *old;
> unsigned long vmstart;
> unsigned long vmend;
> unsigned long end;
> @@ -1521,30 +1521,28 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
> return 0;
> mmap_write_lock(mm);
> for_each_vma_range(vmi, vma, end) {
> - vmstart = max(start, vma->vm_start);
> - vmend = min(end, vma->vm_end);
> - new = mpol_dup(vma_policy(vma));
> - if (IS_ERR(new)) {
> - err = PTR_ERR(new);
> - break;
> - }
> - /*
> - * Only update home node if there is an existing vma policy
> - */
> - if (!new)
> - continue;
> -
> /*
> * If any vma in the range got policy other than MPOL_BIND
> * or MPOL_PREFERRED_MANY we return error. We don't reset
> * the home node for vmas we already updated before.
> */
> - if (new->mode != MPOL_BIND && new->mode != MPOL_PREFERRED_MANY) {
> + old = vma_policy(vma);
> + if (!old)
> + continue;
> + if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) {
> err = -EOPNOTSUPP;
> break;
> }
>
> + new = mpol_dup(vma_policy(vma));
> + if (IS_ERR(new)) {
> + err = PTR_ERR(new);
> + break;
> + }
> +
> new->home_node = home_node;
> + vmstart = max(start, vma->vm_start);
> + vmend = min(end, vma->vm_end);
> err = mbind_range(mm, vmstart, vmend, new);
> mpol_put(new);
> if (err)
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable for set_mempolicy_home_node
2022-12-15 14:33 ` Mathieu Desnoyers
@ 2022-12-15 14:49 ` Michal Hocko
2022-12-15 20:00 ` Mathieu Desnoyers
0 siblings, 1 reply; 9+ messages in thread
From: Michal Hocko @ 2022-12-15 14:49 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: Andrew Morton, linux-kernel, Aneesh Kumar K . V, Ben Widawsky,
Dave Hansen, Feng Tang, Andrea Arcangeli, Mel Gorman,
Mike Kravetz, Randy Dunlap, Vlastimil Babka, Andi Kleen,
Dan Williams, Huang Ying, linux-api, stable
On Thu 15-12-22 09:33:54, Mathieu Desnoyers wrote:
> On 2022-12-15 02:51, Michal Hocko wrote:
[...]
> > Btw. looking at the code again it seems rather pointless to duplicate
> > the policy just to throw it away anyway. A slightly bigger diff but this
> > looks more reasonable to me. What do you think? I can also send it as a
> > clean up on top of your fix.
>
> I think it would be best if this comes as a cleanup on top of my fix. The
> diff is larger than the minimal change needed to fix the leak in stable
> branches.
>
> Your approach looks fine, except for the vma_policy(vma) -> old change
> already spotted by Aneesh.
This shouldn't have any real effect on the functionality. Anyway, here
is a follow up cleanup:
---
From f3fdb6f65fa3977aab13378b8e299b168719577c Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Thu, 15 Dec 2022 15:41:27 +0100
Subject: [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable
for set_mempolicy_home_node
set_mempolicy_home_node tries to duplicate a memory policy before
checking it whether it is applicable for the operation. There is
no real reason for doing that and it might actually be a pointless
memory allocation and deallocation exercise for MPOL_INTERLEAVE.
Not a big problem but we can do better. Simply check the policy before
acting on it.
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
mm/mempolicy.c | 28 ++++++++++++----------------
1 file changed, 12 insertions(+), 16 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 02c8a712282f..becf41e10076 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1489,7 +1489,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- struct mempolicy *new;
+ struct mempolicy *new, *old;
unsigned long vmstart;
unsigned long vmend;
unsigned long end;
@@ -1521,31 +1521,27 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
return 0;
mmap_write_lock(mm);
for_each_vma_range(vmi, vma, end) {
- vmstart = max(start, vma->vm_start);
- vmend = min(end, vma->vm_end);
- new = mpol_dup(vma_policy(vma));
- if (IS_ERR(new)) {
- err = PTR_ERR(new);
- break;
- }
- /*
- * Only update home node if there is an existing vma policy
- */
- if (!new)
- continue;
-
/*
* If any vma in the range got policy other than MPOL_BIND
* or MPOL_PREFERRED_MANY we return error. We don't reset
* the home node for vmas we already updated before.
*/
- if (new->mode != MPOL_BIND && new->mode != MPOL_PREFERRED_MANY) {
- mpol_put(new);
+ old = vma_policy(vma);
+ if (!old)
+ continue;
+ if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) {
err = -EOPNOTSUPP;
break;
}
+ new = mpol_dup(old);
+ if (IS_ERR(new)) {
+ err = PTR_ERR(new);
+ break;
+ }
new->home_node = home_node;
+ vmstart = max(start, vma->vm_start);
+ vmend = min(end, vma->vm_end);
err = mbind_range(mm, vmstart, vmend, new);
mpol_put(new);
if (err)
--
2.30.2
--
Michal Hocko
SUSE Labs
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable for set_mempolicy_home_node
2022-12-15 14:49 ` [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable for set_mempolicy_home_node Michal Hocko
@ 2022-12-15 20:00 ` Mathieu Desnoyers
0 siblings, 0 replies; 9+ messages in thread
From: Mathieu Desnoyers @ 2022-12-15 20:00 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, linux-kernel, Aneesh Kumar K . V, Ben Widawsky,
Dave Hansen, Feng Tang, Andrea Arcangeli, Mel Gorman,
Mike Kravetz, Randy Dunlap, Vlastimil Babka, Andi Kleen,
Dan Williams, Huang Ying, linux-api, stable
On 2022-12-15 09:49, Michal Hocko wrote:
> On Thu 15-12-22 09:33:54, Mathieu Desnoyers wrote:
>> On 2022-12-15 02:51, Michal Hocko wrote:
> [...]
>>> Btw. looking at the code again it seems rather pointless to duplicate
>>> the policy just to throw it away anyway. A slightly bigger diff but this
>>> looks more reasonable to me. What do you think? I can also send it as a
>>> clean up on top of your fix.
>>
>> I think it would be best if this comes as a cleanup on top of my fix. The
>> diff is larger than the minimal change needed to fix the leak in stable
>> branches.
>>
>> Your approach looks fine, except for the vma_policy(vma) -> old change
>> already spotted by Aneesh.
>
> This shouldn't have any real effect on the functionality. Anyway, here
> is a follow up cleanup:
> ---
> From f3fdb6f65fa3977aab13378b8e299b168719577c Mon Sep 17 00:00:00 2001
> From: Michal Hocko <mhocko@suse.com>
> Date: Thu, 15 Dec 2022 15:41:27 +0100
> Subject: [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable
> for set_mempolicy_home_node
>
> set_mempolicy_home_node tries to duplicate a memory policy before
> checking it whether it is applicable for the operation. There is
> no real reason for doing that and it might actually be a pointless
> memory allocation and deallocation exercise for MPOL_INTERLEAVE.
>
> Not a big problem but we can do better. Simply check the policy before
> acting on it.
>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> ---
> mm/mempolicy.c | 28 ++++++++++++----------------
> 1 file changed, 12 insertions(+), 16 deletions(-)
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 02c8a712282f..becf41e10076 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1489,7 +1489,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> - struct mempolicy *new;
> + struct mempolicy *new, *old;
> unsigned long vmstart;
> unsigned long vmend;
> unsigned long end;
> @@ -1521,31 +1521,27 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
> return 0;
> mmap_write_lock(mm);
> for_each_vma_range(vmi, vma, end) {
> - vmstart = max(start, vma->vm_start);
> - vmend = min(end, vma->vm_end);
> - new = mpol_dup(vma_policy(vma));
> - if (IS_ERR(new)) {
> - err = PTR_ERR(new);
> - break;
> - }
> - /*
> - * Only update home node if there is an existing vma policy
> - */
> - if (!new)
> - continue;
> -
> /*
> * If any vma in the range got policy other than MPOL_BIND
> * or MPOL_PREFERRED_MANY we return error. We don't reset
> * the home node for vmas we already updated before.
> */
> - if (new->mode != MPOL_BIND && new->mode != MPOL_PREFERRED_MANY) {
> - mpol_put(new);
> + old = vma_policy(vma);
> + if (!old)
> + continue;
> + if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) {
> err = -EOPNOTSUPP;
> break;
> }
> + new = mpol_dup(old);
> + if (IS_ERR(new)) {
> + err = PTR_ERR(new);
> + break;
> + }
>
> new->home_node = home_node;
> + vmstart = max(start, vma->vm_start);
> + vmend = min(end, vma->vm_end);
> err = mbind_range(mm, vmstart, vmend, new);
> mpol_put(new);
> if (err)
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-12-15 19:59 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-12-14 22:21 [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Mathieu Desnoyers
2022-12-14 23:16 ` Randy Dunlap
2022-12-15 6:34 ` Huang, Ying
2022-12-15 7:51 ` Michal Hocko
2022-12-15 13:57 ` Aneesh Kumar K.V
2022-12-15 14:33 ` Mathieu Desnoyers
2022-12-15 14:49 ` [PATCH] mm/mempolicy: do not duplicate policy if it is not applicable for set_mempolicy_home_node Michal Hocko
2022-12-15 20:00 ` Mathieu Desnoyers
2022-12-15 13:56 ` [RFC PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Aneesh Kumar K.V
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