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release 6.16.5

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This commit is contained in:
Konstantin Demin
2025-09-04 18:10:26 +03:00
parent 8a22827345
commit bbfd90d5dc
32 changed files with 1492 additions and 184 deletions
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110
debian/patches/patchset-pf/steady/0020-mm-fix-possible-deadlock-in-kmemleak.patch vendored Normal file
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@@ -0,0 +1,110 @@
From 8b190cfe2c3ec71bbb031dcf4eab072a4c83c289 Mon Sep 17 00:00:00 2001
From: Gu Bowen <gubowen5@huawei.com>
Date: Fri, 22 Aug 2025 15:35:41 +0800
Subject: mm: fix possible deadlock in kmemleak
There are some AA deadlock issues in kmemleak, similar to the situation
reported by Breno [1]. The deadlock path is as follows:
mem_pool_alloc()
-> raw_spin_lock_irqsave(&kmemleak_lock, flags);
-> pr_warn()
-> netconsole subsystem
-> netpoll
-> __alloc_skb
-> __create_object
-> raw_spin_lock_irqsave(&kmemleak_lock, flags);
To solve this problem, switch to printk_safe mode before printing warning
message, this will redirect all printk()-s to a special per-CPU buffer,
which will be flushed later from a safe context (irq work), and this
deadlock problem can be avoided. The proper API to use should be
printk_deferred_enter()/printk_deferred_exit() [2]. Another way is to
place the warn print after kmemleak is released.
Link: https://lkml.kernel.org/r/20250822073541.1886469-1-gubowen5@huawei.com
Link: https://lore.kernel.org/all/20250731-kmemleak_lock-v1-1-728fd470198f@debian.org/#t [1]
Link: https://lore.kernel.org/all/5ca375cd-4a20-4807-b897-68b289626550@redhat.com/ [2]
Signed-off-by: Gu Bowen <gubowen5@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Lu Jialin <lujialin4@huawei.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/kmemleak.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -437,9 +437,15 @@ static struct kmemleak_object *__lookup_
else if (untagged_objp == untagged_ptr || alias)
return object;
else {
+ /*
+ * Printk deferring due to the kmemleak_lock held.
+ * This is done to avoid deadlock.
+ */
+ printk_deferred_enter();
kmemleak_warn("Found object by alias at 0x%08lx\n",
ptr);
dump_object_info(object);
+ printk_deferred_exit();
break;
}
}
@@ -736,6 +742,11 @@ static int __link_object(struct kmemleak
else if (untagged_objp + parent->size <= untagged_ptr)
link = &parent->rb_node.rb_right;
else {
+ /*
+ * Printk deferring due to the kmemleak_lock held.
+ * This is done to avoid deadlock.
+ */
+ printk_deferred_enter();
kmemleak_stop("Cannot insert 0x%lx into the object search tree (overlaps existing)\n",
ptr);
/*
@@ -743,6 +754,7 @@ static int __link_object(struct kmemleak
* be freed while the kmemleak_lock is held.
*/
dump_object_info(parent);
+ printk_deferred_exit();
return -EEXIST;
}
}
@@ -856,13 +868,8 @@ static void delete_object_part(unsigned
raw_spin_lock_irqsave(&kmemleak_lock, flags);
object = __find_and_remove_object(ptr, 1, objflags);
- if (!object) {
-#ifdef DEBUG
- kmemleak_warn("Partially freeing unknown object at 0x%08lx (size %zu)\n",
- ptr, size);
-#endif
+ if (!object)
goto unlock;
- }
/*
* Create one or two objects that may result from the memory block
@@ -882,8 +889,14 @@ static void delete_object_part(unsigned
unlock:
raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
- if (object)
+ if (object) {
__delete_object(object);
+ } else {
+#ifdef DEBUG
+ kmemleak_warn("Partially freeing unknown object at 0x%08lx (size %zu)\n",
+ ptr, size);
+#endif
+ }
out:
if (object_l)