FAILED: patch "[PATCH] uprobes: Fix the memcg accounting" failed to apply to 4.4-stable tree

PATCH [email protected] 3 participants 4 messages Sep 2, 2016 – Sep 12, 2016

Subsystems (3)

Stable branch perf events uprobes

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[email protected]

author maintainer

2016-09-02 14:09 UTC #0 lore raw

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 6c4687cc17a788a6dd8de3e27dbeabb7cbd3e066 Mon Sep 17 00:00:00 2001

From: Oleg Nesterov <[email protected]>
Date: Wed, 17 Aug 2016 17:36:29 +0200
Subject: [PATCH] uprobes: Fix the memcg accounting

__replace_page() wronlgy calls mem_cgroup_cancel_charge() in "success" path, it should only do this if page_check_address() fails.

This means that every enable/disable leads to unbalanced mem_cgroup_uncharge() from put_page(old_page), it is trivial to underflow the page_counter->count and trigger OOM.

Reported-and-tested-by Brenden Blanco <[email protected]>

Signed-off-by Oleg Nesterov <[email protected]>

Reviewed-by Johannes Weiner <[email protected]>

Acked-by Michal Hocko <[email protected]>

Cc Alexander Shishkin <[email protected]>

Cc Alexei Starovoitov <[email protected]>

Cc Arnaldo Carvalho de Melo <[email protected]>

Cc Jiri Olsa <[email protected]>

Cc Linus Torvalds <[email protected]>

Cc Peter Zijlstra <[email protected]>

Cc Thomas Gleixner <[email protected]>

Cc Vladimir Davydov <[email protected]>

Cc [email protected] # 3.17+

Fixes 00501b531c47 ("mm: memcontrol: rewrite charge API")

Link http://lkml.kernel.org/r/[email protected] open here

Signed-off-by Ingo Molnar <[email protected]>

kernel/events/uprobes.c +3 -2

index b7a525ab2083..8c50276b60d1 100644
@@ -172,8 +172,10 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
 	err = -EAGAIN;
 	ptep = page_check_address(page, mm, addr, &ptl, 0);
-	if (!ptep)
+	if (!ptep) {
+		mem_cgroup_cancel_charge(kpage, memcg, false);
 		goto unlock;
+	}
 
 	get_page(kpage);
 	page_add_new_anon_rmap(kpage, vma, addr, false);

@@ -200,7 +202,6 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 
 	err = 0;
  unlock:
-	mem_cgroup_cancel_charge(kpage, memcg, false);
 	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
 	unlock_page(page);
 	return err;

Michal Hocko

Reviewed-by Johannes Weiner Acked-by

2016-09-12 07:39 UTC #1 lore raw

Quoted 5 lines · Greg KH

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

This should fix it
---

Quoted 1 line

From 714b2350cecc97085429a16a8de78f74804d477b Mon Sep 17 00:00:00 2001

From: Oleg Nesterov <[email protected]>
Date: Wed, 17 Aug 2016 17:36:29 +0200
Subject: [PATCH] uprobes: Fix the memcg accounting

commit 6c4687cc17a788a6dd8de3e27dbeabb7cbd3e066 upstream.

__replace_page() wronlgy calls mem_cgroup_cancel_charge() in "success" path, it should only do this if page_check_address() fails.

This means that every enable/disable leads to unbalanced mem_cgroup_uncharge() from put_page(old_page), it is trivial to underflow the page_counter->count and trigger OOM.

Reported-and-tested-by Brenden Blanco <[email protected]>

Signed-off-by Oleg Nesterov <[email protected]>

Reviewed-by Johannes Weiner <[email protected]>

Acked-by Michal Hocko <[email protected]>

Cc Alexander Shishkin <[email protected]>

Cc Alexei Starovoitov <[email protected]>

Cc Arnaldo Carvalho de Melo <[email protected]>

Cc Jiri Olsa <[email protected]>

Cc Linus Torvalds <[email protected]>

Cc Peter Zijlstra <[email protected]>

Cc Thomas Gleixner <[email protected]>

Cc Vladimir Davydov <[email protected]>

Cc [email protected] # 3.17+

Fixes 00501b531c47 ("mm: memcontrol: rewrite charge API")

Link http://lkml.kernel.org/r/[email protected] open here

Signed-off-by Ingo Molnar <[email protected]>

Signed-off-by Michal Hocko <[email protected]>

---
 kernel/events/uprobes.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

kernel/events/uprobes.c +3 -2

index 7dad84913abf..da0c09ff6112 100644
@@ -171,8 +171,10 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
 	err = -EAGAIN;
 	ptep = page_check_address(page, mm, addr, &ptl, 0);
-	if (!ptep)
+	if (!ptep) {
+		mem_cgroup_cancel_charge(kpage, memcg);
 		goto unlock;
+	}
 
 	get_page(kpage);
 	page_add_new_anon_rmap(kpage, vma, addr);

@@ -199,7 +201,6 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 
 	err = 0;
  unlock:
-	mem_cgroup_cancel_charge(kpage, memcg);
 	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
 	unlock_page(page);
 	return err;

Signature · 5 lines

2.9.3

-- 
Michal Hocko
SUSE Labs

Oleg Nesterov

maintainer

2016-09-12 11:05 UTC #2 lore raw

Quoted 7 lines · Michal Hocko

Quoted 5 lines · Greg KH
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Interestingly, I didn't receive this email...

Quoted 1 line

This should fix it

Yes, thanks a lot Michal!

Oleg.

Greg KH

author maintainer

2016-09-12 14:56 UTC #3 lore raw

In reply to Michal Hocko

Quoted 7 lines · Michal Hocko

Quoted 5 lines · Greg KH
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Quoted 8 lines

This should fix it
---
Quoted 1 line
From 714b2350cecc97085429a16a8de78f74804d477b Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <[email protected]>
Date: Wed, 17 Aug 2016 17:36:29 +0200
Subject: [PATCH] uprobes: Fix the memcg accounting
commit 6c4687cc17a788a6dd8de3e27dbeabb7cbd3e066 upstream.

Thanks, now queued up.

greg k-h