V1 -> V2:
- Because `pmd_val` variable broke ppc builds due to its name,
renamed it to `_pmd`. see [1].
[1] https://lore.kernel.org/stable/aS7lPZPYuChOTdXU@hyeyoo
- Added David Hildenbrand's Acked-by [2], thanks a lot!
[2] https://lore.kernel.org/linux-mm/ac8d7137-3819-4a75-9dd3-fb3d2259ebe4@kerne…
# TL;DR
previous discussion: https://lore.kernel.org/linux-mm/20250921232709.1608699-1-harry.yoo@oracle.…
A "bad pmd" error occurs due to race condition between
change_prot_numa() and THP migration. The mainline kernel does not have
this bug as commit 670ddd8cdc fixes the race condition. 6.1.y, 5.15.y,
5.10.y, 5.4.y are affected by this bug.
Fixing this in -stable kernels is tricky because pte_map_offset_lock()
has different semantics in pre-6.5 and post-6.5 kernels. I am trying to
backport the same mechanism we have in the mainline kernel.
Since the code looks bit different due to different semantics of
pte_map_offset_lock(), it'd be best to get this reviewed by MM folks.
# Testing
I verified that the bug described below is not reproduced anymore
(on a downstream kernel) after applying this patch series. It used to
trigger in few days of intensive numa balancing testing, but it survived
2 weeks with this applied.
# Bug Description
It was reported that a bad pmd is seen when automatic NUMA
balancing is marking page table entries as prot_numa:
[2437548.196018] mm/pgtable-generic.c:50: bad pmd 00000000af22fc02(dffffffe71fbfe02)
[2437548.235022] Call Trace:
[2437548.238234] <TASK>
[2437548.241060] dump_stack_lvl+0x46/0x61
[2437548.245689] panic+0x106/0x2e5
[2437548.249497] pmd_clear_bad+0x3c/0x3c
[2437548.253967] change_pmd_range.isra.0+0x34d/0x3a7
[2437548.259537] change_p4d_range+0x156/0x20e
[2437548.264392] change_protection_range+0x116/0x1a9
[2437548.269976] change_prot_numa+0x15/0x37
[2437548.274774] task_numa_work+0x1b8/0x302
[2437548.279512] task_work_run+0x62/0x95
[2437548.283882] exit_to_user_mode_loop+0x1a4/0x1a9
[2437548.289277] exit_to_user_mode_prepare+0xf4/0xfc
[2437548.294751] ? sysvec_apic_timer_interrupt+0x34/0x81
[2437548.300677] irqentry_exit_to_user_mode+0x5/0x25
[2437548.306153] asm_sysvec_apic_timer_interrupt+0x16/0x1b
This is due to a race condition between change_prot_numa() and
THP migration because the kernel doesn't check is_swap_pmd() and
pmd_trans_huge() atomically:
change_prot_numa() THP migration
======================================================================
- change_pmd_range()
-> is_swap_pmd() returns false,
meaning it's not a PMD migration
entry.
- do_huge_pmd_numa_page()
-> migrate_misplaced_page() sets
migration entries for the THP.
- change_pmd_range()
-> pmd_none_or_clear_bad_unless_trans_huge()
-> pmd_none() and pmd_trans_huge() returns false
- pmd_none_or_clear_bad_unless_trans_huge()
-> pmd_bad() returns true for the migration entry!
The upstream commit 670ddd8cdcbd ("mm/mprotect: delete
pmd_none_or_clear_bad_unless_trans_huge()") closes this race condition
by checking is_swap_pmd() and pmd_trans_huge() atomically.
# Backporting note
commit a79390f5d6a7 ("mm/mprotect: use long for page accountings and retval")
is backported to return an error code (negative value) in
change_pte_range().
Unlike the mainline, pte_offset_map_lock() does not check if the pmd
entry is a migration entry or a hugepage; acquires PTL unconditionally
instead of returning failure. Therefore, it is necessary to keep the
!is_swap_pmd() && !pmd_trans_huge() && !pmd_devmap() checks in
change_pmd_range() before acquiring the PTL.
After acquiring the lock, open-code the semantics of
pte_offset_map_lock() in the mainline kernel; change_pte_range() fails
if the pmd value has changed. This requires adding pmd_old parameter
(pmd_t value that is read before calling the function) to
change_pte_range().
Hugh Dickins (1):
mm/mprotect: delete pmd_none_or_clear_bad_unless_trans_huge()
Peter Xu (1):
mm/mprotect: use long for page accountings and retval
include/linux/hugetlb.h | 4 +-
include/linux/mm.h | 2 +-
mm/hugetlb.c | 4 +-
mm/mempolicy.c | 2 +-
mm/mprotect.c | 107 ++++++++++++++++++++++------------------
5 files changed, 64 insertions(+), 55 deletions(-)
--
2.43.0
When waiting for the PCIe link to come up, both link up and link down
are valid results depending on the device state.
Since the link may come up later and to get rid of the following
mis-reported PM errors. Do not return an -ETIMEDOUT error, as the
outcome has already been reported in dw_pcie_wait_for_link().
PM error logs introduced by the -ETIMEDOUT error return.
imx6q-pcie 33800000.pcie: Phy link never came up
imx6q-pcie 33800000.pcie: PM: dpm_run_callback(): genpd_resume_noirq returns -110
imx6q-pcie 33800000.pcie: PM: failed to resume noirq: error -110
Cc: stable(a)vger.kernel.org
Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume functionality")
Signed-off-by: Richard Zhu <hongxing.zhu(a)nxp.com>
Reviewed-by: Frank Li <Frank.Li(a)nxp.com>
---
drivers/pci/controller/dwc/pcie-designware-host.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 06cbfd9e1f1e..025e11ebd571 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -1245,10 +1245,9 @@ int dw_pcie_resume_noirq(struct dw_pcie *pci)
if (ret)
return ret;
- ret = dw_pcie_wait_for_link(pci);
- if (ret)
- return ret;
+ /* Ignore errors, the link may come up later */
+ dw_pcie_wait_for_link(pci);
- return ret;
+ return 0;
}
EXPORT_SYMBOL_GPL(dw_pcie_resume_noirq);
--
2.37.1
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 193d18f60588e95d62e0f82b6a53893e5f2f19f8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010523-dice-pyramid-9839@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 193d18f60588e95d62e0f82b6a53893e5f2f19f8 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <jouni.malinen(a)oss.qualcomm.com>
Date: Mon, 15 Dec 2025 17:11:34 +0200
Subject: [PATCH] wifi: mac80211: Discard Beacon frames to non-broadcast
address
Beacon frames are required to be sent to the broadcast address, see IEEE
Std 802.11-2020, 11.1.3.1 ("The Address 1 field of the Beacon .. frame
shall be set to the broadcast address"). A unicast Beacon frame might be
used as a targeted attack to get one of the associated STAs to do
something (e.g., using CSA to move it to another channel). As such, it
is better have strict filtering for this on the received side and
discard all Beacon frames that are sent to an unexpected address.
This is even more important for cases where beacon protection is used.
The current implementation in mac80211 is correctly discarding unicast
Beacon frames if the Protected Frame bit in the Frame Control field is
set to 0. However, if that bit is set to 1, the logic used for checking
for configured BIGTK(s) does not actually work. If the driver does not
have logic for dropping unicast Beacon frames with Protected Frame bit
1, these frames would be accepted in mac80211 processing as valid Beacon
frames even though they are not protected. This would allow beacon
protection to be bypassed. While the logic for checking beacon
protection could be extended to cover this corner case, a more generic
check for discard all Beacon frames based on A1=unicast address covers
this without needing additional changes.
Address all these issues by dropping received Beacon frames if they are
sent to a non-broadcast address.
Cc: stable(a)vger.kernel.org
Fixes: af2d14b01c32 ("mac80211: Beacon protection using the new BIGTK (STA)")
Signed-off-by: Jouni Malinen <jouni.malinen(a)oss.qualcomm.com>
Link: https://patch.msgid.link/20251215151134.104501-1-jouni.malinen@oss.qualcomm…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6a1899512d07..e0ccd9749853 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3511,6 +3511,11 @@ ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
return RX_DROP_U_RUNT_ACTION;
+ /* Drop non-broadcast Beacon frames */
+ if (ieee80211_is_beacon(mgmt->frame_control) &&
+ !is_broadcast_ether_addr(mgmt->da))
+ return RX_DROP;
+
if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
ieee80211_is_beacon(mgmt->frame_control) &&
!(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
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 1e5a541420b8c6d87d88eb50b6b978cdeafee1c9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010551-shredding-placidly-0c57@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1e5a541420b8c6d87d88eb50b6b978cdeafee1c9 Mon Sep 17 00:00:00 2001
From: Miaoqian Lin <linmq006(a)gmail.com>
Date: Thu, 11 Dec 2025 12:13:13 +0400
Subject: [PATCH] net: phy: mediatek: fix nvmem cell reference leak in
mt798x_phy_calibration
When nvmem_cell_read() fails in mt798x_phy_calibration(), the function
returns without calling nvmem_cell_put(), leaking the cell reference.
Move nvmem_cell_put() right after nvmem_cell_read() to ensure the cell
reference is always released regardless of the read result.
Found via static analysis and code review.
Fixes: 98c485eaf509 ("net: phy: add driver for MediaTek SoC built-in GE PHYs")
Cc: stable(a)vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006(a)gmail.com>
Reviewed-by: Daniel Golle <daniel(a)makrotopia.org>
Reviewed-by: Andrew Lunn <andrew(a)lunn.ch>
Link: https://patch.msgid.link/20251211081313.2368460-1-linmq006@gmail.com
Signed-off-by: Paolo Abeni <pabeni(a)redhat.com>
diff --git a/drivers/net/phy/mediatek/mtk-ge-soc.c b/drivers/net/phy/mediatek/mtk-ge-soc.c
index cd09fbf92ef2..2c4bbc236202 100644
--- a/drivers/net/phy/mediatek/mtk-ge-soc.c
+++ b/drivers/net/phy/mediatek/mtk-ge-soc.c
@@ -1167,9 +1167,9 @@ static int mt798x_phy_calibration(struct phy_device *phydev)
}
buf = (u32 *)nvmem_cell_read(cell, &len);
+ nvmem_cell_put(cell);
if (IS_ERR(buf))
return PTR_ERR(buf);
- nvmem_cell_put(cell);
if (!buf[0] || !buf[1] || !buf[2] || !buf[3] || len < 4 * sizeof(u32)) {
phydev_err(phydev, "invalid efuse data\n");
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 1e5a541420b8c6d87d88eb50b6b978cdeafee1c9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010550-concise-enjoyment-35f1@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1e5a541420b8c6d87d88eb50b6b978cdeafee1c9 Mon Sep 17 00:00:00 2001
From: Miaoqian Lin <linmq006(a)gmail.com>
Date: Thu, 11 Dec 2025 12:13:13 +0400
Subject: [PATCH] net: phy: mediatek: fix nvmem cell reference leak in
mt798x_phy_calibration
When nvmem_cell_read() fails in mt798x_phy_calibration(), the function
returns without calling nvmem_cell_put(), leaking the cell reference.
Move nvmem_cell_put() right after nvmem_cell_read() to ensure the cell
reference is always released regardless of the read result.
Found via static analysis and code review.
Fixes: 98c485eaf509 ("net: phy: add driver for MediaTek SoC built-in GE PHYs")
Cc: stable(a)vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006(a)gmail.com>
Reviewed-by: Daniel Golle <daniel(a)makrotopia.org>
Reviewed-by: Andrew Lunn <andrew(a)lunn.ch>
Link: https://patch.msgid.link/20251211081313.2368460-1-linmq006@gmail.com
Signed-off-by: Paolo Abeni <pabeni(a)redhat.com>
diff --git a/drivers/net/phy/mediatek/mtk-ge-soc.c b/drivers/net/phy/mediatek/mtk-ge-soc.c
index cd09fbf92ef2..2c4bbc236202 100644
--- a/drivers/net/phy/mediatek/mtk-ge-soc.c
+++ b/drivers/net/phy/mediatek/mtk-ge-soc.c
@@ -1167,9 +1167,9 @@ static int mt798x_phy_calibration(struct phy_device *phydev)
}
buf = (u32 *)nvmem_cell_read(cell, &len);
+ nvmem_cell_put(cell);
if (IS_ERR(buf))
return PTR_ERR(buf);
- nvmem_cell_put(cell);
if (!buf[0] || !buf[1] || !buf[2] || !buf[3] || len < 4 * sizeof(u32)) {
phydev_err(phydev, "invalid efuse data\n");
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 f183663901f21fe0fba8bd31ae894bc529709ee0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010547-early-outnumber-a575@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f183663901f21fe0fba8bd31ae894bc529709ee0 Mon Sep 17 00:00:00 2001
From: Bijan Tabatabai <bijan311(a)gmail.com>
Date: Tue, 16 Dec 2025 14:07:27 -0600
Subject: [PATCH] mm: consider non-anon swap cache folios in
folio_expected_ref_count()
Currently, folio_expected_ref_count() only adds references for the swap
cache if the folio is anonymous. However, according to the comment above
the definition of PG_swapcache in enum pageflags, shmem folios can also
have PG_swapcache set. This patch makes sure references for the swap
cache are added if folio_test_swapcache(folio) is true.
This issue was found when trying to hot-unplug memory in a QEMU/KVM
virtual machine. When initiating hot-unplug when most of the guest memory
is allocated, hot-unplug hangs partway through removal due to migration
failures. The following message would be printed several times, and would
be printed again about every five seconds:
[ 49.641309] migrating pfn b12f25 failed ret:7
[ 49.641310] page: refcount:2 mapcount:0 mapping:0000000033bd8fe2 index:0x7f404d925 pfn:0xb12f25
[ 49.641311] aops:swap_aops
[ 49.641313] flags: 0x300000000030508(uptodate|active|owner_priv_1|reclaim|swapbacked|node=0|zone=3)
[ 49.641314] raw: 0300000000030508 ffffed312c4bc908 ffffed312c4bc9c8 0000000000000000
[ 49.641315] raw: 00000007f404d925 00000000000c823b 00000002ffffffff 0000000000000000
[ 49.641315] page dumped because: migration failure
When debugging this, I found that these migration failures were due to
__migrate_folio() returning -EAGAIN for a small set of folios because the
expected reference count it calculates via folio_expected_ref_count() is
one less than the actual reference count of the folios. Furthermore, all
of the affected folios were not anonymous, but had the PG_swapcache flag
set, inspiring this patch. After applying this patch, the memory
hot-unplug behaves as expected.
I tested this on a machine running Ubuntu 24.04 with kernel version
6.8.0-90-generic and 64GB of memory. The guest VM is managed by libvirt
and runs Ubuntu 24.04 with kernel version 6.18 (though the head of the
mm-unstable branch as a Dec 16, 2025 was also tested and behaves the same)
and 48GB of memory. The libvirt XML definition for the VM can be found at
[1]. CONFIG_MHP_DEFAULT_ONLINE_TYPE_ONLINE_MOVABLE is set in the guest
kernel so the hot-pluggable memory is automatically onlined.
Below are the steps to reproduce this behavior:
1) Define and start and virtual machine
host$ virsh -c qemu:///system define ./test_vm.xml # test_vm.xml from [1]
host$ virsh -c qemu:///system start test_vm
2) Setup swap in the guest
guest$ sudo fallocate -l 32G /swapfile
guest$ sudo chmod 0600 /swapfile
guest$ sudo mkswap /swapfile
guest$ sudo swapon /swapfile
3) Use alloc_data [2] to allocate most of the remaining guest memory
guest$ ./alloc_data 45
4) In a separate guest terminal, monitor the amount of used memory
guest$ watch -n1 free -h
5) When alloc_data has finished allocating, initiate the memory
hot-unplug using the provided xml file [3]
host$ virsh -c qemu:///system detach-device test_vm ./remove.xml --live
After initiating the memory hot-unplug, you should see the amount of
available memory in the guest decrease, and the amount of used swap data
increase. If everything works as expected, when all of the memory is
unplugged, there should be around 8.5-9GB of data in swap. If the
unplugging is unsuccessful, the amount of used swap data will settle below
that. If that happens, you should be able to see log messages in dmesg
similar to the one posted above.
Link: https://lkml.kernel.org/r/20251216200727.2360228-1-bijan311@gmail.com
Link: https://github.com/BijanT/linux_patch_files/blob/main/test_vm.xml [1]
Link: https://github.com/BijanT/linux_patch_files/blob/main/alloc_data.c [2]
Link: https://github.com/BijanT/linux_patch_files/blob/main/remove.xml [3]
Fixes: 86ebd50224c0 ("mm: add folio_expected_ref_count() for reference count calculation")
Signed-off-by: Bijan Tabatabai <bijan311(a)gmail.com>
Acked-by: David Hildenbrand (Red Hat) <david(a)kernel.org>
Acked-by: Zi Yan <ziy(a)nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang(a)linux.alibaba.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Mike Rapoport <rppt(a)kernel.org>
Cc: Shivank Garg <shivankg(a)amd.com>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Kairui Song <ryncsn(a)gmail.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 15076261d0c2..6f959d8ca4b4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2459,10 +2459,10 @@ static inline int folio_expected_ref_count(const struct folio *folio)
if (WARN_ON_ONCE(page_has_type(&folio->page) && !folio_test_hugetlb(folio)))
return 0;
- if (folio_test_anon(folio)) {
- /* One reference per page from the swapcache. */
- ref_count += folio_test_swapcache(folio) << order;
- } else {
+ /* One reference per page from the swapcache. */
+ ref_count += folio_test_swapcache(folio) << order;
+
+ if (!folio_test_anon(folio)) {
/* One reference per page from the pagecache. */
ref_count += !!folio->mapping << order;
/* One reference from PG_private. */
CephFS stores file data across multiple RADOS objects. An object is the
atomic unit of storage, so the writeback code must clean only folios
that belong to the same object with each OSD request.
CephFS also supports RAID0-style striping of file contents: if enabled,
each object stores multiple unbroken "stripe units" covering different
portions of the file; if disabled, a "stripe unit" is simply the whole
object. The stripe unit is (usually) reported as the inode's block size.
Though the writeback logic could, in principle, lock all dirty folios
belonging to the same object, its current design is to lock only a
single stripe unit at a time. Ever since this code was first written,
it has determined this size by checking the inode's block size.
However, the relatively-new fscrypt support needed to reduce the block
size for encrypted inodes to the crypto block size (see 'fixes' commit),
which causes an unnecessarily high number of write operations (~1024x as
many, with 4MiB objects) and grossly degraded performance.
Fix this (and clarify intent) by using i_layout.stripe_unit directly in
ceph_define_write_size() so that encrypted inodes are written back with
the same number of operations as if they were unencrypted.
Fixes: 94af0470924c ("ceph: add some fscrypt guardrails")
Cc: stable(a)vger.kernel.org
Signed-off-by: Sam Edwards <CFSworks(a)gmail.com>
---
fs/ceph/addr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index b3569d44d510..cb1da8e27c2b 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1000,7 +1000,8 @@ unsigned int ceph_define_write_size(struct address_space *mapping)
{
struct inode *inode = mapping->host;
struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode);
- unsigned int wsize = i_blocksize(inode);
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ unsigned int wsize = ci->i_layout.stripe_unit;
if (fsc->mount_options->wsize < wsize)
wsize = fsc->mount_options->wsize;
--
2.51.2