This is a note to let you know that I've just added the patch titled
mm: fix memory leak on mm_init error handling
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-fix-memory-leak-on-mm_init-error-handling.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b20b0368c614c609badfe16fbd113dfb4780acd9 Mon Sep 17 00:00:00 2001
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Date: Thu, 30 Mar 2023 09:38:22 -0400
Subject: mm: fix memory leak on mm_init error handling
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
commit b20b0368c614c609badfe16fbd113dfb4780acd9 upstream.
commit f1a7941243c1 ("mm: convert mm's rss stats into percpu_counter")
introduces a memory leak by missing a call to destroy_context() when a
percpu_counter fails to allocate.
Before introducing the per-cpu counter allocations, init_new_context() was
the last call that could fail in mm_init(), and thus there was no need to
ever invoke destroy_context() in the error paths. Adding the following
percpu counter allocations adds error paths after init_new_context(),
which means its associated destroy_context() needs to be called when
percpu counters fail to allocate.
Link: https://lkml.kernel.org/r/20230330133822.66271-1-mathieu.desnoyers@xxxxxxxxxxxx
Fixes: f1a7941243c1 ("mm: convert mm's rss stats into percpu_counter")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/fork.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1177,6 +1177,7 @@ static struct mm_struct *mm_init(struct
fail_pcpu:
while (i > 0)
percpu_counter_destroy(&mm->rss_stat[--i]);
+ destroy_context(mm);
fail_nocontext:
mm_free_pgd(mm);
fail_nopgd:
Patches currently in stable-queue which might be from mathieu.desnoyers@xxxxxxxxxxxx are
queue-6.2/mm-fix-memory-leak-on-mm_init-error-handling.patch
