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 7890e5b5bb6e386155c6e755fe70e0cdcc77f18e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010501-online-amenity-037a@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7890e5b5bb6e386155c6e755fe70e0cdcc77f18e Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Sat, 1 Nov 2025 11:20:12 -0700
Subject: [PATCH] mm/damon/tests/vaddr-kunit: handle alloc failures in
damon_test_split_evenly_fail()
damon_test_split_evenly_fail() 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/20251101182021.74868-19-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/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h
index 484223f19545..1b0f21c2e376 100644
--- a/mm/damon/tests/vaddr-kunit.h
+++ b/mm/damon/tests/vaddr-kunit.h
@@ -256,7 +256,16 @@ static void damon_test_split_evenly_fail(struct kunit *test,
unsigned long start, unsigned long end, unsigned int nr_pieces)
{
struct damon_target *t = damon_new_target();
- struct damon_region *r = damon_new_region(start, end);
+ struct damon_region *r;
+
+ if (!t)
+ kunit_skip(test, "target alloc fail");
+
+ r = damon_new_region(start, end);
+ if (!r) {
+ damon_free_target(t);
+ kunit_skip(test, "region alloc fail");
+ }
damon_add_region(r, t);
KUNIT_EXPECT_EQ(test,
The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x cdd0f118ef87db8a664fb5ea366fd1766d2df1cd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010524-rarity-cardboard-387f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From cdd0f118ef87db8a664fb5ea366fd1766d2df1cd Mon Sep 17 00:00:00 2001
From: Haoxiang Li <haoxiang_li2024(a)163.com>
Date: Mon, 15 Sep 2025 20:09:38 +0800
Subject: [PATCH] media: mediatek: vcodec: Fix a reference leak in
mtk_vcodec_fw_vpu_init()
vpu_get_plat_device() increases the reference count of the returned
platform device. However, when devm_kzalloc() fails, the reference
is not released, causing a reference leak.
Fix this by calling put_device() on fw_pdev->dev before returning
on the error path.
Fixes: e25a89f743b1 ("media: mtk-vcodec: potential dereference of null pointer")
Cc: stable(a)vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com>
Reviewed-by: Tzung-Bi Shih <tzungbi(a)kernel.org>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne(a)collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
diff --git a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
index 223fb2294894..3632037f78f5 100644
--- a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
+++ b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
@@ -119,8 +119,10 @@ struct mtk_vcodec_fw *mtk_vcodec_fw_vpu_init(void *priv, enum mtk_vcodec_fw_use
vpu_wdt_reg_handler(fw_pdev, mtk_vcodec_vpu_reset_enc_handler, priv, rst_id);
fw = devm_kzalloc(&plat_dev->dev, sizeof(*fw), GFP_KERNEL);
- if (!fw)
+ if (!fw) {
+ put_device(&fw_pdev->dev);
return ERR_PTR(-ENOMEM);
+ }
fw->type = VPU;
fw->ops = &mtk_vcodec_vpu_msg;
fw->pdev = fw_pdev;
From: Brian Norris <briannorris(a)google.com>
When transitioning to D3cold, __pci_set_power_state() will first
transition a device to D3hot. If the device was already in D3hot, this
will add excess work:
(a) read/modify/write PMCSR; and
(b) excess delay (pci_dev_d3_sleep()).
For (b), we already performed the necessary delay on the previous D3hot
entry; this was extra noticeable when evaluating runtime PM transition
latency.
Check whether we're already in the target state before continuing.
Note that __pci_set_power_state() already does this same check for other
state transitions, but D3cold is special because __pci_set_power_state()
converts it to D3hot for the purposes of PMCSR.
This seems to be an oversight in commit 0aacdc957401 ("PCI/PM: Clean up
pci_set_low_power_state()").
Fixes: 0aacdc957401 ("PCI/PM: Clean up pci_set_low_power_state()")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Brian Norris <briannorris(a)google.com>
Signed-off-by: Brian Norris <briannorris(a)chromium.org>
---
drivers/pci/pci.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b0f4d98036cd..7517f1380201 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1539,6 +1539,9 @@ static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state, bool
|| (state == PCI_D2 && !dev->d2_support))
return -EIO;
+ if (state == dev->current_state)
+ return 0;
+
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
if (PCI_POSSIBLE_ERROR(pmcsr)) {
pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n",
--
2.51.0.618.g983fd99d29-goog
The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x cdd0f118ef87db8a664fb5ea366fd1766d2df1cd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010524-anthem-unpainted-c766@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From cdd0f118ef87db8a664fb5ea366fd1766d2df1cd Mon Sep 17 00:00:00 2001
From: Haoxiang Li <haoxiang_li2024(a)163.com>
Date: Mon, 15 Sep 2025 20:09:38 +0800
Subject: [PATCH] media: mediatek: vcodec: Fix a reference leak in
mtk_vcodec_fw_vpu_init()
vpu_get_plat_device() increases the reference count of the returned
platform device. However, when devm_kzalloc() fails, the reference
is not released, causing a reference leak.
Fix this by calling put_device() on fw_pdev->dev before returning
on the error path.
Fixes: e25a89f743b1 ("media: mtk-vcodec: potential dereference of null pointer")
Cc: stable(a)vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com>
Reviewed-by: Tzung-Bi Shih <tzungbi(a)kernel.org>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne(a)collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
diff --git a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
index 223fb2294894..3632037f78f5 100644
--- a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
+++ b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
@@ -119,8 +119,10 @@ struct mtk_vcodec_fw *mtk_vcodec_fw_vpu_init(void *priv, enum mtk_vcodec_fw_use
vpu_wdt_reg_handler(fw_pdev, mtk_vcodec_vpu_reset_enc_handler, priv, rst_id);
fw = devm_kzalloc(&plat_dev->dev, sizeof(*fw), GFP_KERNEL);
- if (!fw)
+ if (!fw) {
+ put_device(&fw_pdev->dev);
return ERR_PTR(-ENOMEM);
+ }
fw->type = VPU;
fw->ops = &mtk_vcodec_vpu_msg;
fw->pdev = fw_pdev;
The patch titled
Subject: mm/page_alloc: prevent pcp corruption with SMP=n
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-page_alloc-prevent-pcp-corruption-with-smp=n.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: Vlastimil Babka <vbabka(a)suse.cz>
Subject: mm/page_alloc: prevent pcp corruption with SMP=n
Date: Mon, 05 Jan 2026 16:08:56 +0100
The kernel test robot has reported:
BUG: spinlock trylock failure on UP on CPU#0, kcompactd0/28
lock: 0xffff888807e35ef0, .magic: dead4ead, .owner: kcompactd0/28, .owner_cpu: 0
CPU: 0 UID: 0 PID: 28 Comm: kcompactd0 Not tainted 6.18.0-rc5-00127-ga06157804399 #1 PREEMPT 8cc09ef94dcec767faa911515ce9e609c45db470
Call Trace:
<IRQ>
__dump_stack (lib/dump_stack.c:95)
dump_stack_lvl (lib/dump_stack.c:123)
dump_stack (lib/dump_stack.c:130)
spin_dump (kernel/locking/spinlock_debug.c:71)
do_raw_spin_trylock (kernel/locking/spinlock_debug.c:?)
_raw_spin_trylock (include/linux/spinlock_api_smp.h:89 kernel/locking/spinlock.c:138)
__free_frozen_pages (mm/page_alloc.c:2973)
___free_pages (mm/page_alloc.c:5295)
__free_pages (mm/page_alloc.c:5334)
tlb_remove_table_rcu (include/linux/mm.h:? include/linux/mm.h:3122 include/asm-generic/tlb.h:220 mm/mmu_gather.c:227 mm/mmu_gather.c:290)
? __cfi_tlb_remove_table_rcu (mm/mmu_gather.c:289)
? rcu_core (kernel/rcu/tree.c:?)
rcu_core (include/linux/rcupdate.h:341 kernel/rcu/tree.c:2607 kernel/rcu/tree.c:2861)
rcu_core_si (kernel/rcu/tree.c:2879)
handle_softirqs (arch/x86/include/asm/jump_label.h:36 include/trace/events/irq.h:142 kernel/softirq.c:623)
__irq_exit_rcu (arch/x86/include/asm/jump_label.h:36 kernel/softirq.c:725)
irq_exit_rcu (kernel/softirq.c:741)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1052)
</IRQ>
<TASK>
RIP: 0010:_raw_spin_unlock_irqrestore (arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194)
free_pcppages_bulk (mm/page_alloc.c:1494)
drain_pages_zone (include/linux/spinlock.h:391 mm/page_alloc.c:2632)
__drain_all_pages (mm/page_alloc.c:2731)
drain_all_pages (mm/page_alloc.c:2747)
kcompactd (mm/compaction.c:3115)
kthread (kernel/kthread.c:465)
? __cfi_kcompactd (mm/compaction.c:3166)
? __cfi_kthread (kernel/kthread.c:412)
ret_from_fork (arch/x86/kernel/process.c:164)
? __cfi_kthread (kernel/kthread.c:412)
ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
</TASK>
Matthew has analyzed the report and identified that in drain_page_zone()
we are in a section protected by spin_lock(&pcp->lock) and then get an
interrupt that attempts spin_trylock() on the same lock. The code is
designed to work this way without disabling IRQs and occasionally fail the
trylock with a fallback. However, the SMP=n spinlock implementation
assumes spin_trylock() will always succeed, and thus it's normally a
no-op. Here the enabled lock debugging catches the problem, but otherwise
it could cause a corruption of the pcp structure.
The problem has been introduced by commit 574907741599 ("mm/page_alloc:
leave IRQs enabled for per-cpu page allocations"). The pcp locking scheme
recognizes the need for disabling IRQs to prevent nesting spin_trylock()
sections on SMP=n, but the need to prevent the nesting in spin_lock() has
not been recognized. Fix it by introducing local wrappers that change the
spin_lock() to spin_lock_iqsave() with SMP=n and use them in all places
that do spin_lock(&pcp->lock).
Link: https://lkml.kernel.org/r/20260105-fix-pcp-up-v1-1-5579662d2071@suse.cz
Fixes: 574907741599 ("mm/page_alloc: leave IRQs enabled for per-cpu page allocations")
Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz>
Reported-by: kernel test robot <oliver.sang(a)intel.com>
Closes: https://lore.kernel.org/oe-lkp/202512101320.e2f2dd6f-lkp@intel.com
Analyzed-by: Matthew Wilcox <willy(a)infradead.org>
Link: https://lore.kernel.org/all/aUW05pyc9nZkvY-1@casper.infradead.org/
Cc: Brendan Jackman <jackmanb(a)google.com>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Mel Gorman <mgorman(a)techsingularity.net>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/page_alloc.c | 45 +++++++++++++++++++++++++++++++++++++--------
1 file changed, 37 insertions(+), 8 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-prevent-pcp-corruption-with-smp=n
+++ a/mm/page_alloc.c
@@ -167,6 +167,31 @@ static inline void __pcp_trylock_noop(un
pcp_trylock_finish(UP_flags); \
})
+/*
+ * With the UP spinlock implementation, when we spin_lock(&pcp->lock) (for i.e.
+ * a potentially remote cpu drain) and get interrupted by an operation that
+ * attempts pcp_spin_trylock(), we can't rely on the trylock failure due to UP
+ * spinlock assumptions making the trylock a no-op. So we have to turn that
+ * spin_lock() to a spin_lock_irqsave(). This works because on UP there are no
+ * remote cpu's so we can only be locking the only existing local one.
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
+static inline void __flags_noop(unsigned long *flags) { }
+#define spin_lock_maybe_irqsave(lock, flags) \
+({ \
+ __flags_noop(&(flags)); \
+ spin_lock(lock); \
+})
+#define spin_unlock_maybe_irqrestore(lock, flags) \
+({ \
+ spin_unlock(lock); \
+ __flags_noop(&(flags)); \
+})
+#else
+#define spin_lock_maybe_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
+#define spin_unlock_maybe_irqrestore(lock, flags) spin_unlock_irqrestore(lock, flags)
+#endif
+
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
@@ -2556,6 +2581,7 @@ static int rmqueue_bulk(struct zone *zon
bool decay_pcp_high(struct zone *zone, struct per_cpu_pages *pcp)
{
int high_min, to_drain, to_drain_batched, batch;
+ unsigned long UP_flags;
bool todo = false;
high_min = READ_ONCE(pcp->high_min);
@@ -2575,9 +2601,9 @@ bool decay_pcp_high(struct zone *zone, s
to_drain = pcp->count - pcp->high;
while (to_drain > 0) {
to_drain_batched = min(to_drain, batch);
- spin_lock(&pcp->lock);
+ spin_lock_maybe_irqsave(&pcp->lock, UP_flags);
free_pcppages_bulk(zone, to_drain_batched, pcp, 0);
- spin_unlock(&pcp->lock);
+ spin_unlock_maybe_irqrestore(&pcp->lock, UP_flags);
todo = true;
to_drain -= to_drain_batched;
@@ -2594,14 +2620,15 @@ bool decay_pcp_high(struct zone *zone, s
*/
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
{
+ unsigned long UP_flags;
int to_drain, batch;
batch = READ_ONCE(pcp->batch);
to_drain = min(pcp->count, batch);
if (to_drain > 0) {
- spin_lock(&pcp->lock);
+ spin_lock_maybe_irqsave(&pcp->lock, UP_flags);
free_pcppages_bulk(zone, to_drain, pcp, 0);
- spin_unlock(&pcp->lock);
+ spin_unlock_maybe_irqrestore(&pcp->lock, UP_flags);
}
}
#endif
@@ -2612,10 +2639,11 @@ void drain_zone_pages(struct zone *zone,
static void drain_pages_zone(unsigned int cpu, struct zone *zone)
{
struct per_cpu_pages *pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
+ unsigned long UP_flags;
int count;
do {
- spin_lock(&pcp->lock);
+ spin_lock_maybe_irqsave(&pcp->lock, UP_flags);
count = pcp->count;
if (count) {
int to_drain = min(count,
@@ -2624,7 +2652,7 @@ static void drain_pages_zone(unsigned in
free_pcppages_bulk(zone, to_drain, pcp, 0);
count -= to_drain;
}
- spin_unlock(&pcp->lock);
+ spin_unlock_maybe_irqrestore(&pcp->lock, UP_flags);
} while (count);
}
@@ -6109,6 +6137,7 @@ static void zone_pcp_update_cacheinfo(st
{
struct per_cpu_pages *pcp;
struct cpu_cacheinfo *cci;
+ unsigned long UP_flags;
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
cci = get_cpu_cacheinfo(cpu);
@@ -6119,12 +6148,12 @@ static void zone_pcp_update_cacheinfo(st
* This can reduce zone lock contention without hurting
* cache-hot pages sharing.
*/
- spin_lock(&pcp->lock);
+ spin_lock_maybe_irqsave(&pcp->lock, UP_flags);
if ((cci->per_cpu_data_slice_size >> PAGE_SHIFT) > 3 * pcp->batch)
pcp->flags |= PCPF_FREE_HIGH_BATCH;
else
pcp->flags &= ~PCPF_FREE_HIGH_BATCH;
- spin_unlock(&pcp->lock);
+ spin_unlock_maybe_irqrestore(&pcp->lock, UP_flags);
}
void setup_pcp_cacheinfo(unsigned int cpu)
_
Patches currently in -mm which might be from vbabka(a)suse.cz are
mm-page_alloc-prevent-pcp-corruption-with-smp=n.patch
mm-page_alloc-thp-prevent-reclaim-for-__gfp_thisnode-thp-allocations.patch