The patch titled
Subject: mm: fix memory leak on mm_init error handling
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-fix-memory-leak-on-mm_init-error-handling.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-memory-leak-on-mm_init-error-handling.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Subject: mm: fix memory leak on mm_init error handling
Date: Thu, 30 Mar 2023 09:38:22 -0400
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>
---
kernel/fork.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/fork.c~mm-fix-memory-leak-on-mm_init-error-handling
+++ a/kernel/fork.c
@@ -1174,6 +1174,7 @@ 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 -mm which might be from mathieu.desnoyers@xxxxxxxxxxxx are
mm-fix-memory-leak-on-mm_init-error-handling.patch
