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 4d6fc29f36341d7795db1d1819b4c15fe9be7b23
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101357-monorail-juror-352b@gregkh' --subject-prefix 'PATCH 6.17.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4d6fc29f36341d7795db1d1819b4c15fe9be7b23 Mon Sep 17 00:00:00 2001
From: Donet Tom <donettom(a)linux.ibm.com>
Date: Wed, 24 Sep 2025 00:16:59 +0530
Subject: [PATCH] mm/ksm: fix incorrect KSM counter handling in mm_struct
during fork
Patch series "mm/ksm: Fix incorrect accounting of KSM counters during
fork", v3.
The first patch in this series fixes the incorrect accounting of KSM
counters such as ksm_merging_pages, ksm_rmap_items, and the global
ksm_zero_pages during fork.
The following patch add a selftest to verify the ksm_merging_pages counter
was updated correctly during fork.
Test Results
============
Without the first patch
-----------------------
# [RUN] test_fork_ksm_merging_page_count
not ok 10 ksm_merging_page in child: 32
With the first patch
--------------------
# [RUN] test_fork_ksm_merging_page_count
ok 10 ksm_merging_pages is not inherited after fork
This patch (of 2):
Currently, the KSM-related counters in `mm_struct`, such as
`ksm_merging_pages`, `ksm_rmap_items`, and `ksm_zero_pages`, are inherited
by the child process during fork. This results in inconsistent
accounting.
When a process uses KSM, identical pages are merged and an rmap item is
created for each merged page. The `ksm_merging_pages` and
`ksm_rmap_items` counters are updated accordingly. However, after a fork,
these counters are copied to the child while the corresponding rmap items
are not. As a result, when the child later triggers an unmerge, there are
no rmap items present in the child, so the counters remain stale, leading
to incorrect accounting.
A similar issue exists with `ksm_zero_pages`, which maintains both a
global counter and a per-process counter. During fork, the per-process
counter is inherited by the child, but the global counter is not
incremented. Since the child also references zero pages, the global
counter should be updated as well. Otherwise, during zero-page unmerge,
both the global and per-process counters are decremented, causing the
global counter to become inconsistent.
To fix this, ksm_merging_pages and ksm_rmap_items are reset to 0 during
fork, and the global ksm_zero_pages counter is updated with the
per-process ksm_zero_pages value inherited by the child. This ensures
that KSM statistics remain accurate and reflect the activity of each
process correctly.
Link: https://lkml.kernel.org/r/cover.1758648700.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/7b9870eb67ccc0d79593940d9dbd4a0b39b5d396.17586487…
Fixes: 7609385337a4 ("ksm: count ksm merging pages for each process")
Fixes: cb4df4cae4f2 ("ksm: count allocated ksm rmap_items for each process")
Fixes: e2942062e01d ("ksm: count all zero pages placed by KSM")
Signed-off-by: Donet Tom <donettom(a)linux.ibm.com>
Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Aboorva Devarajan <aboorvad(a)linux.ibm.com>
Cc: David Hildenbrand <david(a)redhat.com>
Cc: Donet Tom <donettom(a)linux.ibm.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list(a)gmail.com>
Cc: Wei Yang <richard.weiyang(a)gmail.com>
Cc: xu xin <xu.xin16(a)zte.com.cn>
Cc: <stable(a)vger.kernel.org> [6.6+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 22e67ca7cba3..067538fc4d58 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -56,8 +56,14 @@ static inline long mm_ksm_zero_pages(struct mm_struct *mm)
static inline void ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
{
/* Adding mm to ksm is best effort on fork. */
- if (mm_flags_test(MMF_VM_MERGEABLE, oldmm))
+ if (mm_flags_test(MMF_VM_MERGEABLE, oldmm)) {
+ long nr_ksm_zero_pages = atomic_long_read(&mm->ksm_zero_pages);
+
+ mm->ksm_merging_pages = 0;
+ mm->ksm_rmap_items = 0;
+ atomic_long_add(nr_ksm_zero_pages, &ksm_zero_pages);
__ksm_enter(mm);
+ }
}
static inline int ksm_execve(struct mm_struct *mm)
The patch below does not apply to the 5.4-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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 8d33a030c566e1f105cd5bf27f37940b6367f3be
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101316-handmade-imaginary-edf0@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8d33a030c566e1f105cd5bf27f37940b6367f3be Mon Sep 17 00:00:00 2001
From: Zheng Qixing <zhengqixing(a)huawei.com>
Date: Tue, 26 Aug 2025 15:42:04 +0800
Subject: [PATCH] dm: fix NULL pointer dereference in __dm_suspend()
There is a race condition between dm device suspend and table load that
can lead to null pointer dereference. The issue occurs when suspend is
invoked before table load completes:
BUG: kernel NULL pointer dereference, address: 0000000000000054
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 6798 Comm: dmsetup Not tainted 6.6.0-g7e52f5f0ca9b #62
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
RIP: 0010:blk_mq_wait_quiesce_done+0x0/0x50
Call Trace:
<TASK>
blk_mq_quiesce_queue+0x2c/0x50
dm_stop_queue+0xd/0x20
__dm_suspend+0x130/0x330
dm_suspend+0x11a/0x180
dev_suspend+0x27e/0x560
ctl_ioctl+0x4cf/0x850
dm_ctl_ioctl+0xd/0x20
vfs_ioctl+0x1d/0x50
__se_sys_ioctl+0x9b/0xc0
__x64_sys_ioctl+0x19/0x30
x64_sys_call+0x2c4a/0x4620
do_syscall_64+0x9e/0x1b0
The issue can be triggered as below:
T1 T2
dm_suspend table_load
__dm_suspend dm_setup_md_queue
dm_mq_init_request_queue
blk_mq_init_allocated_queue
=> q->mq_ops = set->ops; (1)
dm_stop_queue / dm_wait_for_completion
=> q->tag_set NULL pointer! (2)
=> q->tag_set = set; (3)
Fix this by checking if a valid table (map) exists before performing
request-based suspend and waiting for target I/O. When map is NULL,
skip these table-dependent suspend steps.
Even when map is NULL, no I/O can reach any target because there is
no table loaded; I/O submitted in this state will fail early in the
DM layer. Skipping the table-dependent suspend logic in this case
is safe and avoids NULL pointer dereferences.
Fixes: c4576aed8d85 ("dm: fix request-based dm's use of dm_wait_for_completion")
Cc: stable(a)vger.kernel.org
Signed-off-by: Zheng Qixing <zhengqixing(a)huawei.com>
Signed-off-by: Mikulas Patocka <mpatocka(a)redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7222f20c1a83..66dd5f6ce778 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2908,7 +2908,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
{
bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
- int r;
+ int r = 0;
lockdep_assert_held(&md->suspend_lock);
@@ -2960,7 +2960,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
* Stop md->queue before flushing md->wq in case request-based
* dm defers requests to md->wq from md->queue.
*/
- if (dm_request_based(md)) {
+ if (map && dm_request_based(md)) {
dm_stop_queue(md->queue);
set_bit(DMF_QUEUE_STOPPED, &md->flags);
}
@@ -2972,7 +2972,8 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
* We call dm_wait_for_completion to wait for all existing requests
* to finish.
*/
- r = dm_wait_for_completion(md, task_state);
+ if (map)
+ r = dm_wait_for_completion(md, task_state);
if (!r)
set_bit(dmf_suspended_flag, &md->flags);
Greetings,
I hope this email finds you well.
I am Mrs. Diana Owen contacting you from Reality Trading Group Ltd India.
.
As a new growing company, we are looking for reliable company of your product as seen in your website for urgent purchase order basis.
Could you please give me more details and specification of your products.
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Best Regards,
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Purchase Manager
Company: Reality Trading Group Ltd
According to documentation, the DP PHY on x1e80100 has another clock
called ref.
The current X Elite devices supported upstream work fine without this
clock, because the boot firmware leaves this clock enabled. But we should
not rely on that. Also, when it comes to power management, this clock
needs to be also disabled on suspend. So even though this change breaks
the ABI, it is needed in order to make we disable this clock on runtime
PM, when that is going to be enabled in the driver.
So rework the driver to allow different number of clocks, fix the
dt-bindings schema and add the clock to the DT node as well.
Signed-off-by: Abel Vesa <abel.vesa(a)linaro.org>
---
Changes in v3 (resend)
- picked-up Krzysztof's R-b tag for bindings patch
Changes in v3:
- Use dev_err_probe() on clocks parsing failure.
- Explain why the ABI break is necessary.
- Drop the extra 'clk' suffix from the clock name. So ref instead of
refclk.
- Link to v2: https://lore.kernel.org/r/20250903-phy-qcom-edp-add-missing-refclk-v2-0-d88…
Changes in v2:
- Fix schema by adding the minItems, as suggested by Krzysztof.
- Use devm_clk_bulk_get_all, as suggested by Konrad.
- Rephrase the commit messages to reflect the flexible number of clocks.
- Link to v1: https://lore.kernel.org/r/20250730-phy-qcom-edp-add-missing-refclk-v1-0-6f7…
---
Abel Vesa (3):
dt-bindings: phy: qcom-edp: Add missing clock for X Elite
phy: qcom: edp: Make the number of clocks flexible
arm64: dts: qcom: Add missing TCSR ref clock to the DP PHYs
.../devicetree/bindings/phy/qcom,edp-phy.yaml | 28 +++++++++++++++++++++-
arch/arm64/boot/dts/qcom/x1e80100.dtsi | 12 ++++++----
drivers/phy/qualcomm/phy-qcom-edp.c | 16 ++++++-------
3 files changed, 43 insertions(+), 13 deletions(-)
---
base-commit: 52ba76324a9d7c39830c850999210a36ef023cde
change-id: 20250730-phy-qcom-edp-add-missing-refclk-5ab82828f8e7
Best regards,
--
Abel Vesa <abel.vesa(a)linaro.org>
From: Lance Yang <lance.yang(a)linux.dev>
The blocker tracking mechanism assumes that lock pointers are at least
4-byte aligned to use their lower bits for type encoding.
However, as reported by Eero Tamminen, some architectures like m68k
only guarantee 2-byte alignment of 32-bit values. This breaks the
assumption and causes two related WARN_ON_ONCE checks to trigger.
To fix this, the runtime checks are adjusted to silently ignore any lock
that is not 4-byte aligned, effectively disabling the feature in such
cases and avoiding the related warnings.
Thanks to Geert Uytterhoeven for bisecting!
Reported-by: Eero Tamminen <oak(a)helsinkinet.fi>
Closes: https://lore.kernel.org/lkml/CAMuHMdW7Ab13DdGs2acMQcix5ObJK0O2dG_Fxzr8_g58R…
Fixes: e711faaafbe5 ("hung_task: replace blocker_mutex with encoded blocker")
Cc: <stable(a)vger.kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Lance Yang <lance.yang(a)linux.dev>
---
v1 -> v2:
- Pick RB from Masami - thanks!
- Update the changelog and comments
- https://lore.kernel.org/lkml/20250823050036.7748-1-lance.yang@linux.dev/
include/linux/hung_task.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/include/linux/hung_task.h b/include/linux/hung_task.h
index 34e615c76ca5..c4403eeb7144 100644
--- a/include/linux/hung_task.h
+++ b/include/linux/hung_task.h
@@ -20,6 +20,10 @@
* always zero. So we can use these bits to encode the specific blocking
* type.
*
+ * Note that on architectures where this is not guaranteed, or for any
+ * unaligned lock, this tracking mechanism is silently skipped for that
+ * lock.
+ *
* Type encoding:
* 00 - Blocked on mutex (BLOCKER_TYPE_MUTEX)
* 01 - Blocked on semaphore (BLOCKER_TYPE_SEM)
@@ -45,7 +49,7 @@ static inline void hung_task_set_blocker(void *lock, unsigned long type)
* If the lock pointer matches the BLOCKER_TYPE_MASK, return
* without writing anything.
*/
- if (WARN_ON_ONCE(lock_ptr & BLOCKER_TYPE_MASK))
+ if (lock_ptr & BLOCKER_TYPE_MASK)
return;
WRITE_ONCE(current->blocker, lock_ptr | type);
@@ -53,8 +57,6 @@ static inline void hung_task_set_blocker(void *lock, unsigned long type)
static inline void hung_task_clear_blocker(void)
{
- WARN_ON_ONCE(!READ_ONCE(current->blocker));
-
WRITE_ONCE(current->blocker, 0UL);
}
--
2.49.0
In as102_usb driver, the following race condition occurs:
```
CPU0 CPU1
as102_usb_probe()
kzalloc(); // alloc as102_dev_t
....
usb_register_dev();
open("/path/to/dev"); // open as102 dev
....
usb_deregister_dev();
....
kfree(); // free as102_dev_t
....
close(fd);
as102_release() // UAF!!
as102_usb_release()
kfree(); // DFB!!
```
When a USB character device registered with usb_register_dev() is later
unregistered (via usb_deregister_dev() or disconnect), the device node is
removed so new open() calls fail. However, file descriptors that are
already open do not go away immediately: they remain valid until the last
reference is dropped and the driver's .release() is invoked.
In as102, as102_usb_probe() calls usb_register_dev() and then, on an
error path, does usb_deregister_dev() and frees as102_dev_t right away.
If userspace raced a successful open() before the deregistration, that
open FD will later hit as102_release() --> as102_usb_release() and access
or free as102_dev_t again, occur a race to use-after-free and
double-free vuln.
The fix is to never kfree(as102_dev_t) directly once usb_register_dev()
has succeeded. After deregistration, defer freeing memory to .release().
In other words, let release() perform the last kfree when the final open
FD is closed.
Cc: <stable(a)vger.kernel.org>
Reported-by: syzbot+47321e8fd5a4c84088db(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=47321e8fd5a4c84088db
Fixes: cd19f7d3e39b ("[media] as102: fix leaks at failure paths in as102_usb_probe()")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
---
v2: Fix incorrect patch description style and CC stable mailing list
- Link to v1: https://lore.kernel.org/all/20250822143539.1157329-1-aha310510@gmail.com/
---
drivers/media/usb/as102/as102_usb_drv.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/media/usb/as102/as102_usb_drv.c b/drivers/media/usb/as102/as102_usb_drv.c
index e0ef66a522e2..abde5666b2ee 100644
--- a/drivers/media/usb/as102/as102_usb_drv.c
+++ b/drivers/media/usb/as102/as102_usb_drv.c
@@ -404,6 +404,7 @@ static int as102_usb_probe(struct usb_interface *intf,
as102_free_usb_stream_buffer(as102_dev);
failed_stream:
usb_deregister_dev(intf, &as102_usb_class_driver);
+ return ret;
failed:
usb_put_dev(as102_dev->bus_adap.usb_dev);
usb_set_intfdata(intf, NULL);
--
In hackrf driver, the following race condition occurs:
```
CPU0 CPU1
hackrf_probe()
kzalloc(); // alloc hackrf_dev
....
v4l2_device_register();
....
open("/path/to/dev"); // open hackrf dev
....
v4l2_device_unregister();
....
kfree(); // free hackrf_dev
....
ioctl(fd, ...);
v4l2_ioctl();
video_is_registered() // UAF!!
....
close(fd);
v4l2_release() // UAF!!
hackrf_video_release()
kfree(); // DFB!!
```
When a V4L2 or video device is unregistered, the device node is removed so
new open() calls are blocked.
However, file descriptors that are already open-and any in-flight I/O-do
not terminate immediately; they remain valid until the last reference is
dropped and the driver's release() is invoked.
Therefore, freeing device memory on the error path after hackrf_probe()
has registered dev it will lead to a race to use-after-free vuln, since
those already-open handles haven't been released yet.
And since release() free memory too, race to use-after-free and
double-free vuln occur.
To prevent this, if device is registered from probe(), it should be
modified to free memory only through release() rather than calling
kfree() directly.
Cc: <stable(a)vger.kernel.org>
Reported-by: syzbot+6ffd76b5405c006a46b7(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6ffd76b5405c006a46b7
Reported-by: syzbot+f1b20958f93d2d250727(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f1b20958f93d2d250727
Fixes: 8bc4a9ed8504 ("[media] hackrf: add support for transmitter")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
---
v2: Fix incorrect patch description style and CC stable mailing list
- Link to v1: https://lore.kernel.org/all/20250822142729.1156816-1-aha310510@gmail.com/
---
drivers/media/usb/hackrf/hackrf.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/media/usb/hackrf/hackrf.c b/drivers/media/usb/hackrf/hackrf.c
index 0b50de8775a3..d7a84422193d 100644
--- a/drivers/media/usb/hackrf/hackrf.c
+++ b/drivers/media/usb/hackrf/hackrf.c
@@ -1515,6 +1515,8 @@ static int hackrf_probe(struct usb_interface *intf,
video_unregister_device(&dev->rx_vdev);
err_v4l2_device_unregister:
v4l2_device_unregister(&dev->v4l2_dev);
+ dev_dbg(&intf->dev, "failed=%d\n", ret);
+ return ret;
err_v4l2_ctrl_handler_free_tx:
v4l2_ctrl_handler_free(&dev->tx_ctrl_handler);
err_v4l2_ctrl_handler_free_rx:
--
The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: ebfc8542ad62d066771e46c8aa30f5624b89cad8
Gitweb: https://git.kernel.org/tip/ebfc8542ad62d066771e46c8aa30f5624b89cad8
Author: Adrian Hunter <adrian.hunter(a)intel.com>
AuthorDate: Mon, 13 Oct 2025 10:22:42 +03:00
Committer: Peter Zijlstra <peterz(a)infradead.org>
CommitterDate: Tue, 14 Oct 2025 10:38:09 +02:00
perf/core: Fix address filter match with backing files
It was reported that Intel PT address filters do not work in Docker
containers. That relates to the use of overlayfs.
overlayfs records the backing file in struct vm_area_struct vm_file,
instead of the user file that the user mmapped. In order for an address
filter to match, it must compare to the user file inode. There is an
existing helper file_user_inode() for that situation.
Use file_user_inode() instead of file_inode() to get the inode for address
filter matching.
Example:
Setup:
# cd /root
# mkdir test ; cd test ; mkdir lower upper work merged
# cp `which cat` lower
# mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
# perf record --buildid-mmap -e intel_pt//u --filter 'filter * @ /root/test/merged/cat' -- /root/test/merged/cat /proc/self/maps
...
55d61d246000-55d61d2e1000 r-xp 00018000 00:1a 3418 /root/test/merged/cat
...
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.015 MB perf.data ]
# perf buildid-cache --add /root/test/merged/cat
Before:
Address filter does not match so there are no control flow packets
# perf script --itrace=e
# perf script --itrace=b | wc -l
0
# perf script -D | grep 'TIP.PGE' | wc -l
0
#
After:
Address filter does match so there are control flow packets
# perf script --itrace=e
# perf script --itrace=b | wc -l
235
# perf script -D | grep 'TIP.PGE' | wc -l
57
#
With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels. FMODE_BACKING that it depends on was added
in v6.5. This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.
Closes: https://lore.kernel.org/linux-perf-users/aBCwoq7w8ohBRQCh@fremen.lan
Reported-by: Edd Barrett <edd(a)theunixzoo.co.uk>
Signed-off-by: Adrian Hunter <adrian.hunter(a)intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Acked-by: Amir Goldstein <amir73il(a)gmail.com>
Cc: stable(a)vger.kernel.org # 6.8
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7541f6f..cd63ec8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9492,7 +9492,7 @@ static bool perf_addr_filter_match(struct perf_addr_filter *filter,
if (!filter->path.dentry)
return false;
- if (d_inode(filter->path.dentry) != file_inode(file))
+ if (d_inode(filter->path.dentry) != file_user_inode(file))
return false;
if (filter->offset > offset + size)