The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 74d5969995d129fd59dd93b9c7daa6669cb6810f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010548-consent-fried-e16b@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 74d5969995d129fd59dd93b9c7daa6669cb6810f Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:20:04 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures in
damon_test_set_regions()
damon_test_set_regions() is assuming all dynamic memory allocation in it
will succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-11-sj@kernel.org
Fixes: 62f409560eb2 ("mm/damon/core-test: test damon_set_regions")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [6.1+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 96c8f1269f44..e38c95f86a68 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -368,13 +368,26 @@ static void damon_test_ops_registration(struct kunit *test)
static void damon_test_set_regions(struct kunit *test)
{
struct damon_target *t = damon_new_target();
- struct damon_region *r1 = damon_new_region(4, 16);
- struct damon_region *r2 = damon_new_region(24, 32);
+ struct damon_region *r1, *r2;
struct damon_addr_range range = {.start = 8, .end = 28};
unsigned long expects[] = {8, 16, 16, 24, 24, 28};
int expect_idx = 0;
struct damon_region *r;
+ if (!t)
+ kunit_skip(test, "target alloc fail");
+ r1 = damon_new_region(4, 16);
+ if (!r1) {
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
+ r2 = damon_new_region(24, 32);
+ if (!r2) {
+ damon_free_target(t);
+ damon_free_region(r1);
+ kunit_skip(test, "second region alloc fail");
+ }
+
damon_add_region(r1, t);
damon_add_region(r2, t);
damon_set_regions(t, &range, 1, DAMON_MIN_REGION);
The patch titled
Subject: maple_tree: add dead node check in mas_dup_alloc()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
maple_tree-add-dead-node-check-in-mas_dup_alloc.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Boudewijn van der Heide <boudewijn(a)delta-utec.com>
Subject: maple_tree: add dead node check in mas_dup_alloc()
Date: Sat, 3 Jan 2026 17:57:58 +0100
__mt_dup() is exported and can be called without internal locking, relying
on the caller to provide appropriate synchronization. If a caller fails
to hold proper locks, the source tree may be modified concurrently,
potentially resulting in dead nodes during traversal.
The call stack is:
__mt_dup()
��� mas_dup_build()
��� mas_dup_alloc() [accesses node->slot[]]
mas_dup_alloc() may access node slots without first verifying that the
node is still alive. If a dead node is encountered, its memory layout may
have been switched to the RCU union member, making slot array access
undefined behavior as we would be reading from the rcu_head structure
instead.
If __mt_dup() is invoked without the required external locking and the
source tree is concurrently modified, a node can transition to the dead
RCU layout while mas_dup_alloc() is still traversing it. In that case the
code may interpret the rcu_head contents as slot pointers.
Practically, this could lead to invalid pointer dereferences (kernel oops)
or corruption of the duplicated tree. Depending on how that duplicated
tree is later used (e.g. in mm/VMA paths), the effects could be
userspace-visible, such as fork() failures, process crashes, or broader
system instability.
My understanding is that current in-tree users hold the appropriate locks
and should not hit this, as triggering it requires violating the
__mt_dup() synchronization contract. The risk primarily comes from the
fact that __mt_dup() is exported (EXPORT_SYMBOL), making it reachable by
out-of-tree modules or future callers which may not follow the locking
rules.
Add an explicit dead node check to detect concurrent modification during
duplication. When a dead node is detected, return -EBUSY to indicate that
the tree is undergoing concurrent modification.
Link: https://lkml.kernel.org/r/20260103165758.74094-1-boudewijn@delta-utec.com
Fixes: fd32e4e9b764 ("maple_tree: introduce interfaces __mt_dup() and mtree_dup()")
Signed-off-by: Boudewijn van der Heide <boudewijn(a)delta-utec.com>
Cc: Alice Ryhl <aliceryhl(a)google.com>
Cc: Andrew Ballance <andrewjballance(a)gmail.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
lib/maple_tree.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/lib/maple_tree.c~maple_tree-add-dead-node-check-in-mas_dup_alloc
+++ a/lib/maple_tree.c
@@ -6251,6 +6251,11 @@ static inline void mas_dup_alloc(struct
/* Allocate memory for child nodes. */
type = mte_node_type(mas->node);
new_slots = ma_slots(new_node, type);
+ if (unlikely(ma_dead_node(node))) {
+ mas_set_err(mas, -EBUSY);
+ return;
+ }
+
count = mas->node_request = mas_data_end(mas) + 1;
mas_alloc_nodes(mas, gfp);
if (unlikely(mas_is_err(mas)))
_
Patches currently in -mm which might be from boudewijn(a)delta-utec.com are
maple_tree-add-dead-node-check-in-mas_dup_alloc.patch
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x d14d5671e7c9cc788c5a1edfa94e6f9064275905
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010525-threaten-recliner-cac7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d14d5671e7c9cc788c5a1edfa94e6f9064275905 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:20:09 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures on
damos_test_filter_out()
damon_test_filter_out() is assuming all dynamic memory allocation in it
will succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-16-sj@kernel.org
Fixes: 26713c890875 ("mm/damon/core-test: add a unit test for __damos_filter_out()")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [6.6+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 5af8275ffd7d..a03ae9ddd88a 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -542,11 +542,22 @@ static void damos_test_filter_out(struct kunit *test)
struct damos_filter *f;
f = damos_new_filter(DAMOS_FILTER_TYPE_ADDR, true, false);
+ if (!f)
+ kunit_skip(test, "filter alloc fail");
f->addr_range = (struct damon_addr_range){
.start = DAMON_MIN_REGION * 2, .end = DAMON_MIN_REGION * 6};
t = damon_new_target();
+ if (!t) {
+ damos_destroy_filter(f);
+ kunit_skip(test, "target alloc fail");
+ }
r = damon_new_region(DAMON_MIN_REGION * 3, DAMON_MIN_REGION * 5);
+ if (!r) {
+ damos_destroy_filter(f);
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
damon_add_region(r, t);
/* region in the range */
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x eded254cb69044bd4abde87394ea44909708d7c0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010533-uncounted-stuffing-5fb6@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From eded254cb69044bd4abde87394ea44909708d7c0 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:20:02 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures on
damon_test_split_regions_of()
damon_test_split_regions_of() is assuming all dynamic memory allocation in
it will succeed. Those are indeed likely in the real use cases since
those allocations are too small to fail, but theoretically those could
fail. In the case, inappropriate memory access can happen. Fix it by
appropriately cleanup pre-allocated memory and skip the execution of the
remaining tests in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-9-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 98f2a3de7cea..10618cdd188e 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -278,15 +278,35 @@ static void damon_test_split_regions_of(struct kunit *test)
struct damon_target *t;
struct damon_region *r;
+ if (!c)
+ kunit_skip("ctx alloc fail");
t = damon_new_target();
+ if (!t) {
+ damon_destroy_ctx(c);
+ kunit_skip(test, "target alloc fail");
+ }
r = damon_new_region(0, 22);
+ if (!r) {
+ damon_destroy_ctx(c);
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
damon_add_region(r, t);
damon_split_regions_of(t, 2, DAMON_MIN_REGION);
KUNIT_EXPECT_LE(test, damon_nr_regions(t), 2u);
damon_free_target(t);
t = damon_new_target();
+ if (!t) {
+ damon_destroy_ctx(c);
+ kunit_skip(test, "second target alloc fail");
+ }
r = damon_new_region(0, 220);
+ if (!r) {
+ damon_destroy_ctx(c);
+ damon_free_target(t);
+ kunit_skip(test, "second region alloc fail");
+ }
damon_add_region(r, t);
damon_split_regions_of(t, 4, DAMON_MIN_REGION);
KUNIT_EXPECT_LE(test, damon_nr_regions(t), 4u);
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x fafe953de2c661907c94055a2497c6b8dbfd26f3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010535-tumbling-unread-bbf4@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fafe953de2c661907c94055a2497c6b8dbfd26f3 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:19:57 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle memory failure from
damon_test_target()
damon_test_target() is assuming all dynamic memory allocation in it will
succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-4-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index a2c9ee7a5de1..6e8a605277a3 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -58,7 +58,14 @@ static void damon_test_target(struct kunit *test)
struct damon_ctx *c = damon_new_ctx();
struct damon_target *t;
+ if (!c)
+ kunit_skip(test, "ctx alloc fail");
+
t = damon_new_target();
+ if (!t) {
+ damon_destroy_ctx(c);
+ kunit_skip(test, "target alloc fail");
+ }
KUNIT_EXPECT_EQ(test, 0u, nr_damon_targets(c));
damon_add_target(c, t);
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 3d443dd29a1db7efa587a4bb0c06a497e13ca9e4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010518-overflow-headgear-2f02@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3d443dd29a1db7efa587a4bb0c06a497e13ca9e4 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:20:00 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures on
damon_test_merge_two()
damon_test_merge_two() is assuming all dynamic memory allocation in it
will succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-7-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index f5f3152cb8df..e8219fd23318 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -188,11 +188,21 @@ static void damon_test_merge_two(struct kunit *test)
int i;
t = damon_new_target();
+ if (!t)
+ kunit_skip(test, "target alloc fail");
r = damon_new_region(0, 100);
+ if (!r) {
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
r->nr_accesses = 10;
r->nr_accesses_bp = 100000;
damon_add_region(r, t);
r2 = damon_new_region(100, 300);
+ if (!r2) {
+ damon_free_target(t);
+ kunit_skip(test, "second region alloc fail");
+ }
r2->nr_accesses = 20;
r2->nr_accesses_bp = 200000;
damon_add_region(r2, t);
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 0998d2757218771c59d5ca59ccf13d1542a38f17
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010500-pamperer-electable-b002@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0998d2757218771c59d5ca59ccf13d1542a38f17 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:20:01 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures on
dasmon_test_merge_regions_of()
damon_test_merge_regions_of() is assuming all dynamic memory allocation in
it will succeed. Those are indeed likely in the real use cases since
those allocations are too small to fail, but theoretically those could
fail. In the case, inappropriate memory access can happen. Fix it by
appropriately cleanup pre-allocated memory and skip the execution of the
remaining tests in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-8-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index e8219fd23318..98f2a3de7cea 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -248,8 +248,14 @@ static void damon_test_merge_regions_of(struct kunit *test)
int i;
t = damon_new_target();
+ if (!t)
+ kunit_skip(test, "target alloc fail");
for (i = 0; i < ARRAY_SIZE(sa); i++) {
r = damon_new_region(sa[i], ea[i]);
+ if (!r) {
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
r->nr_accesses = nrs[i];
r->nr_accesses_bp = nrs[i] * 10000;
damon_add_region(r, t);
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x e16fdd4f754048d6e23c56bd8d920b71e41e3777
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010522-unrelated-secluded-4f8f@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e16fdd4f754048d6e23c56bd8d920b71e41e3777 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:19:56 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle allocation failures in
damon_test_regions()
damon_test_regions() is assuming all dynamic memory allocation in it will
succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-3-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 69ca44f9270b..a2c9ee7a5de1 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -20,11 +20,17 @@ static void damon_test_regions(struct kunit *test)
struct damon_target *t;
r = damon_new_region(1, 2);
+ if (!r)
+ kunit_skip(test, "region alloc fail");
KUNIT_EXPECT_EQ(test, 1ul, r->ar.start);
KUNIT_EXPECT_EQ(test, 2ul, r->ar.end);
KUNIT_EXPECT_EQ(test, 0u, r->nr_accesses);
t = damon_new_target();
+ if (!t) {
+ damon_free_region(r);
+ kunit_skip(test, "target alloc fail");
+ }
KUNIT_EXPECT_EQ(test, 0u, damon_nr_regions(t));
damon_add_region(r, t);
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 5e80d73f22043c59c8ad36452a3253937ed77955
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010507-underfed-amends-4275@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5e80d73f22043c59c8ad36452a3253937ed77955 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:19:59 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures on
damon_test_split_at()
damon_test_split_at() is assuming all dynamic memory allocation in it will
succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-6-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index fd1e1ecaa2c9..f5f3152cb8df 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -148,8 +148,19 @@ static void damon_test_split_at(struct kunit *test)
struct damon_target *t;
struct damon_region *r, *r_new;
+ if (!c)
+ kunit_skip(test, "ctx alloc fail");
t = damon_new_target();
+ if (!t) {
+ damon_destroy_ctx(c);
+ kunit_skip(test, "target alloc fail");
+ }
r = damon_new_region(0, 100);
+ if (!r) {
+ damon_destroy_ctx(c);
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
r->nr_accesses_bp = 420000;
r->nr_accesses = 42;
r->last_nr_accesses = 15;
The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x f79f2fc44ebd0ed655239046be3e80e8804b5545
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010545-sesame-antsy-7700@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f79f2fc44ebd0ed655239046be3e80e8804b5545 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:19:58 -0700
Subject: [PATCH] mm/damon/tests/core-kunit: handle memory alloc failure from
damon_test_aggregate()
damon_test_aggregate() is assuming all dynamic memory allocation in it
will succeed. Those are indeed likely in the real use cases since those
allocations are too small to fail, but theoretically those could fail. In
the case, inappropriate memory access can happen. Fix it by appropriately
cleanup pre-allocated memory and skip the execution of the remaining tests
in the failure cases.
Link: https://lkml.kernel.org/r/20251101182021.74868-5-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: David Gow <davidgow(a)google.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 6e8a605277a3..fd1e1ecaa2c9 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -97,8 +97,15 @@ static void damon_test_aggregate(struct kunit *test)
struct damon_region *r;
int it, ir;
+ if (!ctx)
+ kunit_skip(test, "ctx alloc fail");
+
for (it = 0; it < 3; it++) {
t = damon_new_target();
+ if (!t) {
+ damon_destroy_ctx(ctx);
+ kunit_skip(test, "target alloc fail");
+ }
damon_add_target(ctx, t);
}
@@ -106,6 +113,10 @@ static void damon_test_aggregate(struct kunit *test)
damon_for_each_target(t, ctx) {
for (ir = 0; ir < 3; ir++) {
r = damon_new_region(saddr[it][ir], eaddr[it][ir]);
+ if (!r) {
+ damon_destroy_ctx(ctx);
+ kunit_skip(test, "region alloc fail");
+ }
r->nr_accesses = accesses[it][ir];
r->nr_accesses_bp = accesses[it][ir] * 10000;
damon_add_region(r, t);