The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 4b1ff850e0c1aacc23e923ed22989b827b9808f9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101650-setback-proofs-9687@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4b1ff850e0c1aacc23e923ed22989b827b9808f9 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Thu, 25 Sep 2025 12:32:36 +0200
Subject: [PATCH] mptcp: pm: in-kernel: usable client side with C-flag
When servers set the C-flag in their MP_CAPABLE to tell clients not to
create subflows to the initial address and port, clients will likely not
use their other endpoints. That's because the in-kernel path-manager
uses the 'subflow' endpoints to create subflows only to the initial
address and port.
If the limits have not been modified to accept ADD_ADDR, the client
doesn't try to establish new subflows. If the limits accept ADD_ADDR,
the routing routes will be used to select the source IP.
The C-flag is typically set when the server is operating behind a legacy
Layer 4 load balancer, or using anycast IP address. Clients having their
different 'subflow' endpoints setup, don't end up creating multiple
subflows as expected, and causing some deployment issues.
A special case is then added here: when servers set the C-flag in the
MPC and directly sends an ADD_ADDR, this single ADD_ADDR is accepted.
The 'subflows' endpoints will then be used with this new remote IP and
port. This exception is only allowed when the ADD_ADDR is sent
immediately after the 3WHS, and makes the client switching to the 'fully
established' mode. After that, 'select_local_address()' will not be able
to find any subflows, because 'id_avail_bitmap' will be filled in
mptcp_pm_create_subflow_or_signal_addr(), when switching to 'fully
established' mode.
Fixes: df377be38725 ("mptcp: add deny_join_id0 in mptcp_options_received")
Cc: stable(a)vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/536
Reviewed-by: Geliang Tang <geliang(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-1-ad126c…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 204e1f61212e..584cab90aa6e 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -637,9 +637,12 @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
} else {
__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
}
- /* id0 should not have a different address */
+ /* - id0 should not have a different address
+ * - special case for C-flag: linked to fill_local_addresses_vec()
+ */
} else if ((addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
- (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
+ (addr->id > 0 && !READ_ONCE(pm->accept_addr) &&
+ !mptcp_pm_add_addr_c_flag_case(msk))) {
mptcp_pm_announce_addr(msk, addr, true);
mptcp_pm_add_addr_send_ack(msk);
} else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index 667803d72b64..8c46493a0835 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -389,10 +389,12 @@ static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
struct mptcp_addr_info mpc_addr;
struct pm_nl_pernet *pernet;
unsigned int subflows_max;
+ bool c_flag_case;
int i = 0;
pernet = pm_nl_get_pernet_from_msk(msk);
subflows_max = mptcp_pm_get_subflows_max(msk);
+ c_flag_case = remote->id && mptcp_pm_add_addr_c_flag_case(msk);
mptcp_local_address((struct sock_common *)msk, &mpc_addr);
@@ -405,12 +407,27 @@ static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
continue;
if (msk->pm.subflows < subflows_max) {
+ bool is_id0;
+
locals[i].addr = entry->addr;
locals[i].flags = entry->flags;
locals[i].ifindex = entry->ifindex;
+ is_id0 = mptcp_addresses_equal(&locals[i].addr,
+ &mpc_addr,
+ locals[i].addr.port);
+
+ if (c_flag_case &&
+ (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)) {
+ __clear_bit(locals[i].addr.id,
+ msk->pm.id_avail_bitmap);
+
+ if (!is_id0)
+ msk->pm.local_addr_used++;
+ }
+
/* Special case for ID0: set the correct ID */
- if (mptcp_addresses_equal(&locals[i].addr, &mpc_addr, locals[i].addr.port))
+ if (is_id0)
locals[i].addr.id = 0;
msk->pm.subflows++;
@@ -419,6 +436,37 @@ static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
}
rcu_read_unlock();
+ /* Special case: peer sets the C flag, accept one ADD_ADDR if default
+ * limits are used -- accepting no ADD_ADDR -- and use subflow endpoints
+ */
+ if (!i && c_flag_case) {
+ unsigned int local_addr_max = mptcp_pm_get_local_addr_max(msk);
+
+ while (msk->pm.local_addr_used < local_addr_max &&
+ msk->pm.subflows < subflows_max) {
+ struct mptcp_pm_local *local = &locals[i];
+
+ if (!select_local_address(pernet, msk, local))
+ break;
+
+ __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
+
+ if (!mptcp_pm_addr_families_match(sk, &local->addr,
+ remote))
+ continue;
+
+ if (mptcp_addresses_equal(&local->addr, &mpc_addr,
+ local->addr.port))
+ continue;
+
+ msk->pm.local_addr_used++;
+ msk->pm.subflows++;
+ i++;
+ }
+
+ return i;
+ }
+
/* If the array is empty, fill in the single
* 'IPADDRANY' local address
*/
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a1787a1344ac..cbe54331e5c7 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1199,6 +1199,14 @@ static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
spin_unlock_bh(&msk->pm.lock);
}
+static inline bool mptcp_pm_add_addr_c_flag_case(struct mptcp_sock *msk)
+{
+ return READ_ONCE(msk->pm.remote_deny_join_id0) &&
+ msk->pm.local_addr_used == 0 &&
+ mptcp_pm_get_add_addr_accept_max(msk) == 0 &&
+ msk->pm.subflows < mptcp_pm_get_subflows_max(msk);
+}
+
void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
The patch below does not apply to the 6.17-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-6.17.y
git checkout FETCH_HEAD
git cherry-pick -x baf60d5cb8bc6b85511c5df5f0ad7620bb66d23c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101647-crushable-wiring-b094@gregkh' --subject-prefix 'PATCH 6.17.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From baf60d5cb8bc6b85511c5df5f0ad7620bb66d23c Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Mon, 15 Sep 2025 20:28:52 +0200
Subject: [PATCH] ACPI: property: Do not pass NULL handles to
acpi_attach_data()
In certain circumstances, the ACPI handle of a data-only node may be
NULL, in which case it does not make sense to attempt to attach that
node to an ACPI namespace object, so update the code to avoid attempts
to do so.
This prevents confusing and unuseful error messages from being printed.
Also document the fact that the ACPI handle of a data-only node may be
NULL and when that happens in a code comment. In addition, make
acpi_add_nondev_subnodes() print a diagnostic message for each data-only
node with an unknown ACPI namespace scope.
Fixes: 1d52f10917a7 ("ACPI: property: Tie data nodes to acpi handles")
Cc: 6.0+ <stable(a)vger.kernel.org> # 6.0+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus(a)linux.intel.com>
Tested-by: Sakari Ailus <sakari.ailus(a)linux.intel.com>
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index f4776a4085e0..c086786fe84c 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -124,6 +124,10 @@ static bool acpi_nondev_subnode_extract(union acpi_object *desc,
result = true;
if (result) {
+ /*
+ * This will be NULL if the desc package is embedded in an outer
+ * _DSD-equivalent package and its scope cannot be determined.
+ */
dn->handle = handle;
dn->data.pointer = desc;
list_add_tail(&dn->sibling, list);
@@ -224,6 +228,8 @@ static bool acpi_add_nondev_subnodes(acpi_handle scope,
* strings because there is no way to build full
* pathnames out of them.
*/
+ acpi_handle_debug(scope, "subnode %s: Unknown scope\n",
+ link->package.elements[0].string.pointer);
desc = &link->package.elements[1];
result = acpi_nondev_subnode_extract(desc, NULL, link,
list, parent);
@@ -396,6 +402,9 @@ static void acpi_untie_nondev_subnodes(struct acpi_device_data *data)
struct acpi_data_node *dn;
list_for_each_entry(dn, &data->subnodes, sibling) {
+ if (!dn->handle)
+ continue;
+
acpi_detach_data(dn->handle, acpi_nondev_subnode_tag);
acpi_untie_nondev_subnodes(&dn->data);
@@ -410,6 +419,9 @@ static bool acpi_tie_nondev_subnodes(struct acpi_device_data *data)
acpi_status status;
bool ret;
+ if (!dn->handle)
+ continue;
+
status = acpi_attach_data(dn->handle, acpi_nondev_subnode_tag, dn);
if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
acpi_handle_err(dn->handle, "Can't tag data node\n");
Hi, Sasha,
On Wed, Oct 15, 2025 at 7:42 PM Sasha Levin <sashal(a)kernel.org> wrote:
>
> This is a note to let you know that I've just added the patch titled
>
> LoongArch: Init acpi_gbl_use_global_lock to false
>
> to the 6.12-stable tree which can be found at:
> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
>
> The filename of the patch is:
> loongarch-init-acpi_gbl_use_global_lock-to-false.patch
> and it can be found in the queue-6.12 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable(a)vger.kernel.org> know about it.
>
Please also backport feb8ae81b2378b75a99c81d3156 ("ACPICA: Allow to
skip Global Lock initialization") as a dependency for all stable
branches.
Huacai
>
>
> commit abbcba805d220623909699cbeb81b739d3dd5a06
> Author: Huacai Chen <chenhuacai(a)kernel.org>
> Date: Thu Oct 2 22:38:57 2025 +0800
>
> LoongArch: Init acpi_gbl_use_global_lock to false
>
> [ Upstream commit 98662be7ef20d2b88b598f72e7ce9b6ac26a40f9 ]
>
> Init acpi_gbl_use_global_lock to false, in order to void error messages
> during boot phase:
>
> ACPI Error: Could not enable GlobalLock event (20240827/evxfevnt-182)
> ACPI Error: No response from Global Lock hardware, disabling lock (20240827/evglock-59)
>
> Fixes: 628c3bb40e9a8cefc0a6 ("LoongArch: Add boot and setup routines")
> Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn>
> Signed-off-by: Sasha Levin <sashal(a)kernel.org>
>
> diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
> index 1fa6a604734ef..2ceb198ae8c80 100644
> --- a/arch/loongarch/kernel/setup.c
> +++ b/arch/loongarch/kernel/setup.c
> @@ -354,6 +354,7 @@ void __init platform_init(void)
>
> #ifdef CONFIG_ACPI
> acpi_table_upgrade();
> + acpi_gbl_use_global_lock = false;
> acpi_gbl_use_default_register_widths = false;
> acpi_boot_table_init();
> #endif
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 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101634-energize-tartness-d7b6@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Tue, 16 Sep 2025 23:22:47 -0400
Subject: [PATCH] ext4: avoid potential buffer over-read in
parse_apply_sb_mount_options()
Unlike other strings in the ext4 superblock, we rely on tune2fs to
make sure s_mount_opts is NUL terminated. Harden
parse_apply_sb_mount_options() by treating s_mount_opts as a potential
__nonstring.
Cc: stable(a)vger.kernel.org
Fixes: 8b67f04ab9de ("ext4: Add mount options in superblock")
Reviewed-by: Jan Kara <jack(a)suse.cz>
Reviewed-by: Darrick J. Wong <djwong(a)kernel.org>
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Message-ID: <20250916-tune2fs-v2-1-d594dc7486f0(a)mit.edu>
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d26e5c0731e5..488f4c281a3f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2469,7 +2469,7 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
struct ext4_fs_context *m_ctx)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- char *s_mount_opts = NULL;
+ char s_mount_opts[65];
struct ext4_fs_context *s_ctx = NULL;
struct fs_context *fc = NULL;
int ret = -ENOMEM;
@@ -2477,15 +2477,11 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
if (!sbi->s_es->s_mount_opts[0])
return 0;
- s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
- sizeof(sbi->s_es->s_mount_opts),
- GFP_KERNEL);
- if (!s_mount_opts)
- return ret;
+ strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts);
fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
if (!fc)
- goto out_free;
+ return -ENOMEM;
s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
if (!s_ctx)
@@ -2517,11 +2513,8 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
ret = 0;
out_free:
- if (fc) {
- ext4_fc_free(fc);
- kfree(fc);
- }
- kfree(s_mount_opts);
+ ext4_fc_free(fc);
+ kfree(fc);
return ret;
}
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 399dbcadc01ebf0035f325eaa8c264f8b5cd0a14
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101635-disaster-pasture-f32d@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 399dbcadc01ebf0035f325eaa8c264f8b5cd0a14 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Sun, 28 Sep 2025 12:18:29 +0200
Subject: [PATCH] ACPI: battery: Add synchronization between interface updates
There is no synchronization between different code paths in the ACPI
battery driver that update its sysfs interface or its power supply
class device interface. In some cases this results to functional
failures due to race conditions.
One example of this is when two ACPI notifications:
- ACPI_BATTERY_NOTIFY_STATUS (0x80)
- ACPI_BATTERY_NOTIFY_INFO (0x81)
are triggered (by the platform firmware) in a row with a little delay
in between after removing and reinserting a laptop battery. Both
notifications cause acpi_battery_update() to be called and if the delay
between them is sufficiently small, sysfs_add_battery() can be re-entered
before battery->bat is set which leads to a duplicate sysfs entry error:
sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT1'
CPU: 1 UID: 0 PID: 185 Comm: kworker/1:4 Kdump: loaded Not tainted 6.12.38+deb13-amd64 #1 Debian 6.12.38-1
Hardware name: Gateway NV44 /SJV40-MV , BIOS V1.3121 04/08/2009
Workqueue: kacpi_notify acpi_os_execute_deferred
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
sysfs_warn_dup.cold+0x17/0x23
sysfs_create_dir_ns+0xce/0xe0
kobject_add_internal+0xba/0x250
kobject_add+0x96/0xc0
? get_device_parent+0xde/0x1e0
device_add+0xe2/0x870
__power_supply_register.part.0+0x20f/0x3f0
? wake_up_q+0x4e/0x90
sysfs_add_battery+0xa4/0x1d0 [battery]
acpi_battery_update+0x19e/0x290 [battery]
acpi_battery_notify+0x50/0x120 [battery]
acpi_ev_notify_dispatch+0x49/0x70
acpi_os_execute_deferred+0x1a/0x30
process_one_work+0x177/0x330
worker_thread+0x251/0x390
? __pfx_worker_thread+0x10/0x10
kthread+0xd2/0x100
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
kobject: kobject_add_internal failed for BAT1 with -EEXIST, don't try to register things with the same name in the same directory.
There are also other scenarios in which analogous issues may occur.
Address this by using a common lock in all of the code paths leading
to updates of driver interfaces: ACPI Notify () handler, system resume
callback and post-resume notification, device addition and removal.
This new lock replaces sysfs_lock that has been used only in
sysfs_remove_battery() which now is going to be always called under
the new lock, so it doesn't need any internal locking any more.
Fixes: 10666251554c ("ACPI: battery: Install Notify() handler directly")
Closes: https://lore.kernel.org/linux-acpi/20250910142653.313360-1-luogf2025@163.co…
Reported-by: GuangFei Luo <luogf2025(a)163.com>
Tested-by: GuangFei Luo <luogf2025(a)163.com>
Cc: 6.6+ <stable(a)vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 6905b56bf3e4..67b76492c839 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -92,7 +92,7 @@ enum {
struct acpi_battery {
struct mutex lock;
- struct mutex sysfs_lock;
+ struct mutex update_lock;
struct power_supply *bat;
struct power_supply_desc bat_desc;
struct acpi_device *device;
@@ -904,15 +904,12 @@ static int sysfs_add_battery(struct acpi_battery *battery)
static void sysfs_remove_battery(struct acpi_battery *battery)
{
- mutex_lock(&battery->sysfs_lock);
- if (!battery->bat) {
- mutex_unlock(&battery->sysfs_lock);
+ if (!battery->bat)
return;
- }
+
battery_hook_remove_battery(battery);
power_supply_unregister(battery->bat);
battery->bat = NULL;
- mutex_unlock(&battery->sysfs_lock);
}
static void find_battery(const struct dmi_header *dm, void *private)
@@ -1072,6 +1069,9 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
if (!battery)
return;
+
+ guard(mutex)(&battery->update_lock);
+
old = battery->bat;
/*
* On Acer Aspire V5-573G notifications are sometimes triggered too
@@ -1094,21 +1094,22 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
}
static int battery_notify(struct notifier_block *nb,
- unsigned long mode, void *_unused)
+ unsigned long mode, void *_unused)
{
struct acpi_battery *battery = container_of(nb, struct acpi_battery,
pm_nb);
- int result;
- switch (mode) {
- case PM_POST_HIBERNATION:
- case PM_POST_SUSPEND:
+ if (mode == PM_POST_SUSPEND || mode == PM_POST_HIBERNATION) {
+ guard(mutex)(&battery->update_lock);
+
if (!acpi_battery_present(battery))
return 0;
if (battery->bat) {
acpi_battery_refresh(battery);
} else {
+ int result;
+
result = acpi_battery_get_info(battery);
if (result)
return result;
@@ -1120,7 +1121,6 @@ static int battery_notify(struct notifier_block *nb,
acpi_battery_init_alarm(battery);
acpi_battery_get_state(battery);
- break;
}
return 0;
@@ -1198,6 +1198,8 @@ static int acpi_battery_update_retry(struct acpi_battery *battery)
{
int retry, ret;
+ guard(mutex)(&battery->update_lock);
+
for (retry = 5; retry; retry--) {
ret = acpi_battery_update(battery, false);
if (!ret)
@@ -1208,6 +1210,13 @@ static int acpi_battery_update_retry(struct acpi_battery *battery)
return ret;
}
+static void sysfs_battery_cleanup(struct acpi_battery *battery)
+{
+ guard(mutex)(&battery->update_lock);
+
+ sysfs_remove_battery(battery);
+}
+
static int acpi_battery_add(struct acpi_device *device)
{
int result = 0;
@@ -1230,7 +1239,7 @@ static int acpi_battery_add(struct acpi_device *device)
if (result)
return result;
- result = devm_mutex_init(&device->dev, &battery->sysfs_lock);
+ result = devm_mutex_init(&device->dev, &battery->update_lock);
if (result)
return result;
@@ -1262,7 +1271,7 @@ static int acpi_battery_add(struct acpi_device *device)
device_init_wakeup(&device->dev, 0);
unregister_pm_notifier(&battery->pm_nb);
fail:
- sysfs_remove_battery(battery);
+ sysfs_battery_cleanup(battery);
return result;
}
@@ -1281,6 +1290,9 @@ static void acpi_battery_remove(struct acpi_device *device)
device_init_wakeup(&device->dev, 0);
unregister_pm_notifier(&battery->pm_nb);
+
+ guard(mutex)(&battery->update_lock);
+
sysfs_remove_battery(battery);
}
@@ -1297,6 +1309,9 @@ static int acpi_battery_resume(struct device *dev)
return -EINVAL;
battery->update_time = 0;
+
+ guard(mutex)(&battery->update_lock);
+
acpi_battery_update(battery, true);
return 0;
}
The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 399dbcadc01ebf0035f325eaa8c264f8b5cd0a14
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101634-factsheet-preplan-069e@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 399dbcadc01ebf0035f325eaa8c264f8b5cd0a14 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Sun, 28 Sep 2025 12:18:29 +0200
Subject: [PATCH] ACPI: battery: Add synchronization between interface updates
There is no synchronization between different code paths in the ACPI
battery driver that update its sysfs interface or its power supply
class device interface. In some cases this results to functional
failures due to race conditions.
One example of this is when two ACPI notifications:
- ACPI_BATTERY_NOTIFY_STATUS (0x80)
- ACPI_BATTERY_NOTIFY_INFO (0x81)
are triggered (by the platform firmware) in a row with a little delay
in between after removing and reinserting a laptop battery. Both
notifications cause acpi_battery_update() to be called and if the delay
between them is sufficiently small, sysfs_add_battery() can be re-entered
before battery->bat is set which leads to a duplicate sysfs entry error:
sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT1'
CPU: 1 UID: 0 PID: 185 Comm: kworker/1:4 Kdump: loaded Not tainted 6.12.38+deb13-amd64 #1 Debian 6.12.38-1
Hardware name: Gateway NV44 /SJV40-MV , BIOS V1.3121 04/08/2009
Workqueue: kacpi_notify acpi_os_execute_deferred
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
sysfs_warn_dup.cold+0x17/0x23
sysfs_create_dir_ns+0xce/0xe0
kobject_add_internal+0xba/0x250
kobject_add+0x96/0xc0
? get_device_parent+0xde/0x1e0
device_add+0xe2/0x870
__power_supply_register.part.0+0x20f/0x3f0
? wake_up_q+0x4e/0x90
sysfs_add_battery+0xa4/0x1d0 [battery]
acpi_battery_update+0x19e/0x290 [battery]
acpi_battery_notify+0x50/0x120 [battery]
acpi_ev_notify_dispatch+0x49/0x70
acpi_os_execute_deferred+0x1a/0x30
process_one_work+0x177/0x330
worker_thread+0x251/0x390
? __pfx_worker_thread+0x10/0x10
kthread+0xd2/0x100
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
kobject: kobject_add_internal failed for BAT1 with -EEXIST, don't try to register things with the same name in the same directory.
There are also other scenarios in which analogous issues may occur.
Address this by using a common lock in all of the code paths leading
to updates of driver interfaces: ACPI Notify () handler, system resume
callback and post-resume notification, device addition and removal.
This new lock replaces sysfs_lock that has been used only in
sysfs_remove_battery() which now is going to be always called under
the new lock, so it doesn't need any internal locking any more.
Fixes: 10666251554c ("ACPI: battery: Install Notify() handler directly")
Closes: https://lore.kernel.org/linux-acpi/20250910142653.313360-1-luogf2025@163.co…
Reported-by: GuangFei Luo <luogf2025(a)163.com>
Tested-by: GuangFei Luo <luogf2025(a)163.com>
Cc: 6.6+ <stable(a)vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 6905b56bf3e4..67b76492c839 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -92,7 +92,7 @@ enum {
struct acpi_battery {
struct mutex lock;
- struct mutex sysfs_lock;
+ struct mutex update_lock;
struct power_supply *bat;
struct power_supply_desc bat_desc;
struct acpi_device *device;
@@ -904,15 +904,12 @@ static int sysfs_add_battery(struct acpi_battery *battery)
static void sysfs_remove_battery(struct acpi_battery *battery)
{
- mutex_lock(&battery->sysfs_lock);
- if (!battery->bat) {
- mutex_unlock(&battery->sysfs_lock);
+ if (!battery->bat)
return;
- }
+
battery_hook_remove_battery(battery);
power_supply_unregister(battery->bat);
battery->bat = NULL;
- mutex_unlock(&battery->sysfs_lock);
}
static void find_battery(const struct dmi_header *dm, void *private)
@@ -1072,6 +1069,9 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
if (!battery)
return;
+
+ guard(mutex)(&battery->update_lock);
+
old = battery->bat;
/*
* On Acer Aspire V5-573G notifications are sometimes triggered too
@@ -1094,21 +1094,22 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
}
static int battery_notify(struct notifier_block *nb,
- unsigned long mode, void *_unused)
+ unsigned long mode, void *_unused)
{
struct acpi_battery *battery = container_of(nb, struct acpi_battery,
pm_nb);
- int result;
- switch (mode) {
- case PM_POST_HIBERNATION:
- case PM_POST_SUSPEND:
+ if (mode == PM_POST_SUSPEND || mode == PM_POST_HIBERNATION) {
+ guard(mutex)(&battery->update_lock);
+
if (!acpi_battery_present(battery))
return 0;
if (battery->bat) {
acpi_battery_refresh(battery);
} else {
+ int result;
+
result = acpi_battery_get_info(battery);
if (result)
return result;
@@ -1120,7 +1121,6 @@ static int battery_notify(struct notifier_block *nb,
acpi_battery_init_alarm(battery);
acpi_battery_get_state(battery);
- break;
}
return 0;
@@ -1198,6 +1198,8 @@ static int acpi_battery_update_retry(struct acpi_battery *battery)
{
int retry, ret;
+ guard(mutex)(&battery->update_lock);
+
for (retry = 5; retry; retry--) {
ret = acpi_battery_update(battery, false);
if (!ret)
@@ -1208,6 +1210,13 @@ static int acpi_battery_update_retry(struct acpi_battery *battery)
return ret;
}
+static void sysfs_battery_cleanup(struct acpi_battery *battery)
+{
+ guard(mutex)(&battery->update_lock);
+
+ sysfs_remove_battery(battery);
+}
+
static int acpi_battery_add(struct acpi_device *device)
{
int result = 0;
@@ -1230,7 +1239,7 @@ static int acpi_battery_add(struct acpi_device *device)
if (result)
return result;
- result = devm_mutex_init(&device->dev, &battery->sysfs_lock);
+ result = devm_mutex_init(&device->dev, &battery->update_lock);
if (result)
return result;
@@ -1262,7 +1271,7 @@ static int acpi_battery_add(struct acpi_device *device)
device_init_wakeup(&device->dev, 0);
unregister_pm_notifier(&battery->pm_nb);
fail:
- sysfs_remove_battery(battery);
+ sysfs_battery_cleanup(battery);
return result;
}
@@ -1281,6 +1290,9 @@ static void acpi_battery_remove(struct acpi_device *device)
device_init_wakeup(&device->dev, 0);
unregister_pm_notifier(&battery->pm_nb);
+
+ guard(mutex)(&battery->update_lock);
+
sysfs_remove_battery(battery);
}
@@ -1297,6 +1309,9 @@ static int acpi_battery_resume(struct device *dev)
return -EINVAL;
battery->update_time = 0;
+
+ guard(mutex)(&battery->update_lock);
+
acpi_battery_update(battery, true);
return 0;
}
The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x e4f574ca9c6dfa66695bb054ff5df43ecea873ec
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101610-ranch-sincerity-0fc4@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e4f574ca9c6dfa66695bb054ff5df43ecea873ec Mon Sep 17 00:00:00 2001
From: Scott Mayhew <smayhew(a)redhat.com>
Date: Wed, 6 Aug 2025 15:15:43 -0400
Subject: [PATCH] nfsd: decouple the xprtsec policy check from
check_nfsd_access()
A while back I had reported that an NFSv3 client could successfully
mount using '-o xprtsec=none' an export that had been exported with
'xprtsec=tls:mtls'. By "successfully" I mean that the mount command
would succeed and the mount would show up in /proc/mount. Attempting
to do anything futher with the mount would be met with NFS3ERR_ACCES.
This was fixed (albeit accidentally) by commit bb4f07f2409c ("nfsd:
Fix NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT") and was
subsequently re-broken by commit 0813c5f01249 ("nfsd: fix access
checking for NLM under XPRTSEC policies").
Transport Layer Security isn't an RPC security flavor or pseudo-flavor,
so we shouldn't be conflating them when determining whether the access
checks can be bypassed. Split check_nfsd_access() into two helpers, and
have __fh_verify() call the helpers directly since __fh_verify() has
logic that allows one or both of the checks to be skipped. All other
sites will continue to call check_nfsd_access().
Link: https://lore.kernel.org/linux-nfs/ZjO3Qwf_G87yNXb2@aion/
Fixes: 9280c5774314 ("NFSD: Handle new xprtsec= export option")
Cc: stable(a)vger.kernel.org
Signed-off-by: Scott Mayhew <smayhew(a)redhat.com>
Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com>
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index cadfc2bae60e..95b5681152c4 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1082,50 +1082,62 @@ static struct svc_export *exp_find(struct cache_detail *cd,
}
/**
- * check_nfsd_access - check if access to export is allowed.
+ * check_xprtsec_policy - check if access to export is allowed by the
+ * xprtsec policy
* @exp: svc_export that is being accessed.
- * @rqstp: svc_rqst attempting to access @exp (will be NULL for LOCALIO).
- * @may_bypass_gss: reduce strictness of authorization check
+ * @rqstp: svc_rqst attempting to access @exp.
+ *
+ * Helper function for check_nfsd_access(). Note that callers should be
+ * using check_nfsd_access() instead of calling this function directly. The
+ * one exception is __fh_verify() since it has logic that may result in one
+ * or both of the helpers being skipped.
*
* Return values:
* %nfs_ok if access is granted, or
* %nfserr_wrongsec if access is denied
*/
-__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
- bool may_bypass_gss)
+__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp)
{
- struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
- struct svc_xprt *xprt;
-
- /*
- * If rqstp is NULL, this is a LOCALIO request which will only
- * ever use a filehandle/credential pair for which access has
- * been affirmed (by ACCESS or OPEN NFS requests) over the
- * wire. So there is no need for further checks here.
- */
- if (!rqstp)
- return nfs_ok;
-
- xprt = rqstp->rq_xprt;
+ struct svc_xprt *xprt = rqstp->rq_xprt;
if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) {
if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags))
- goto ok;
+ return nfs_ok;
}
if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) {
if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
!test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
- goto ok;
+ return nfs_ok;
}
if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) {
if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
- goto ok;
+ return nfs_ok;
}
- if (!may_bypass_gss)
- goto denied;
+ return nfserr_wrongsec;
+}
+
+/**
+ * check_security_flavor - check if access to export is allowed by the
+ * security flavor
+ * @exp: svc_export that is being accessed.
+ * @rqstp: svc_rqst attempting to access @exp.
+ * @may_bypass_gss: reduce strictness of authorization check
+ *
+ * Helper function for check_nfsd_access(). Note that callers should be
+ * using check_nfsd_access() instead of calling this function directly. The
+ * one exception is __fh_verify() since it has logic that may result in one
+ * or both of the helpers being skipped.
+ *
+ * Return values:
+ * %nfs_ok if access is granted, or
+ * %nfserr_wrongsec if access is denied
+ */
+__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp,
+ bool may_bypass_gss)
+{
+ struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
-ok:
/* legacy gss-only clients are always OK: */
if (exp->ex_client == rqstp->rq_gssclient)
return nfs_ok;
@@ -1167,10 +1179,30 @@ __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
}
}
-denied:
return nfserr_wrongsec;
}
+/**
+ * check_nfsd_access - check if access to export is allowed.
+ * @exp: svc_export that is being accessed.
+ * @rqstp: svc_rqst attempting to access @exp.
+ * @may_bypass_gss: reduce strictness of authorization check
+ *
+ * Return values:
+ * %nfs_ok if access is granted, or
+ * %nfserr_wrongsec if access is denied
+ */
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
+ bool may_bypass_gss)
+{
+ __be32 status;
+
+ status = check_xprtsec_policy(exp, rqstp);
+ if (status != nfs_ok)
+ return status;
+ return check_security_flavor(exp, rqstp, may_bypass_gss);
+}
+
/*
* Uses rq_client and rq_gssclient to find an export; uses rq_client (an
* auth_unix client) if it's available and has secinfo information;
diff --git a/fs/nfsd/export.h b/fs/nfsd/export.h
index b9c0adb3ce09..ef5581911d5b 100644
--- a/fs/nfsd/export.h
+++ b/fs/nfsd/export.h
@@ -101,6 +101,9 @@ struct svc_expkey {
struct svc_cred;
int nfsexp_flags(struct svc_cred *cred, struct svc_export *exp);
+__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp);
+__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp,
+ bool may_bypass_gss);
__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
bool may_bypass_gss);
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index f4c2fb3dd5d0..062cfc18d8c6 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -364,10 +364,30 @@ __fh_verify(struct svc_rqst *rqstp,
if (error)
goto out;
+ /*
+ * If rqstp is NULL, this is a LOCALIO request which will only
+ * ever use a filehandle/credential pair for which access has
+ * been affirmed (by ACCESS or OPEN NFS requests) over the
+ * wire. Skip both the xprtsec policy and the security flavor
+ * checks.
+ */
+ if (!rqstp)
+ goto check_permissions;
+
if ((access & NFSD_MAY_NLM) && (exp->ex_flags & NFSEXP_NOAUTHNLM))
/* NLM is allowed to fully bypass authentication */
goto out;
+ /*
+ * NLM is allowed to bypass the xprtsec policy check because lockd
+ * doesn't support xprtsec.
+ */
+ if (!(access & NFSD_MAY_NLM)) {
+ error = check_xprtsec_policy(exp, rqstp);
+ if (error)
+ goto out;
+ }
+
if (access & NFSD_MAY_BYPASS_GSS)
may_bypass_gss = true;
/*
@@ -379,13 +399,15 @@ __fh_verify(struct svc_rqst *rqstp,
&& exp->ex_path.dentry == dentry)
may_bypass_gss = true;
- error = check_nfsd_access(exp, rqstp, may_bypass_gss);
+ error = check_security_flavor(exp, rqstp, may_bypass_gss);
if (error)
goto out;
+
/* During LOCALIO call to fh_verify will be called with a NULL rqstp */
if (rqstp)
svc_xprt_set_valid(rqstp->rq_xprt);
+check_permissions:
/* Finally, check access permissions. */
error = nfsd_permission(cred, exp, dentry, access);
out: