The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 8d63c83d8eb922f6c316320f50c82fa88d099bea
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091724-unrivaled-crystal-942a@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8d63c83d8eb922f6c316320f50c82fa88d099bea Mon Sep 17 00:00:00 2001
From: Alan Stern <stern(a)rowland.harvard.edu>
Date: Mon, 25 Aug 2025 12:00:22 -0400
Subject: [PATCH] USB: gadget: dummy-hcd: Fix locking bug in RT-enabled kernels
Yunseong Kim and the syzbot fuzzer both reported a problem in
RT-enabled kernels caused by the way dummy-hcd mixes interrupt
management and spin-locking. The pattern was:
local_irq_save(flags);
spin_lock(&dum->lock);
...
spin_unlock(&dum->lock);
... // calls usb_gadget_giveback_request()
local_irq_restore(flags);
The code was written this way because usb_gadget_giveback_request()
needs to be called with interrupts disabled and the private lock not
held.
While this pattern works fine in non-RT kernels, it's not good when RT
is enabled. RT kernels handle spinlocks much like mutexes; in particular,
spin_lock() may sleep. But sleeping is not allowed while local
interrupts are disabled.
To fix the problem, rewrite the code to conform to the pattern used
elsewhere in dummy-hcd and other UDC drivers:
spin_lock_irqsave(&dum->lock, flags);
...
spin_unlock(&dum->lock);
usb_gadget_giveback_request(...);
spin_lock(&dum->lock);
...
spin_unlock_irqrestore(&dum->lock, flags);
This approach satisfies the RT requirements.
Signed-off-by: Alan Stern <stern(a)rowland.harvard.edu>
Cc: stable <stable(a)kernel.org>
Fixes: b4dbda1a22d2 ("USB: dummy-hcd: disable interrupts during req->complete")
Reported-by: Yunseong Kim <ysk(a)kzalloc.com>
Closes: <https://lore.kernel.org/linux-usb/5b337389-73b9-4ee4-a83e-7e82bf5af87a@kzal…>
Reported-by: syzbot+8baacc4139f12fa77909(a)syzkaller.appspotmail.com
Closes: <https://lore.kernel.org/linux-usb/68ac2411.050a0220.37038e.0087.GAE@google.…>
Tested-by: syzbot+8baacc4139f12fa77909(a)syzkaller.appspotmail.com
CC: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
CC: stable(a)vger.kernel.org
Reviewed-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Link: https://lore.kernel.org/r/bb192ae2-4eee-48ee-981f-3efdbbd0d8f0@rowland.harv…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index 21dbfb0b3bac..1cefca660773 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -765,8 +765,7 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
if (!dum->driver)
return -ESHUTDOWN;
- local_irq_save(flags);
- spin_lock(&dum->lock);
+ spin_lock_irqsave(&dum->lock, flags);
list_for_each_entry(iter, &ep->queue, queue) {
if (&iter->req != _req)
continue;
@@ -776,15 +775,16 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
retval = 0;
break;
}
- spin_unlock(&dum->lock);
if (retval == 0) {
dev_dbg(udc_dev(dum),
"dequeued req %p from %s, len %d buf %p\n",
req, _ep->name, _req->length, _req->buf);
+ spin_unlock(&dum->lock);
usb_gadget_giveback_request(_ep, _req);
+ spin_lock(&dum->lock);
}
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&dum->lock, flags);
return retval;
}
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 64961557efa1b98f375c0579779e7eeda1a02c42
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091751-almanac-unused-2e7b@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 64961557efa1b98f375c0579779e7eeda1a02c42 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 24 Jul 2025 15:12:05 +0200
Subject: [PATCH] phy: ti: omap-usb2: fix device leak at unbind
Make sure to drop the reference to the control device taken by
of_find_device_by_node() during probe when the driver is unbound.
Fixes: 478b6c7436c2 ("usb: phy: omap-usb2: Don't use omap_get_control_dev()")
Cc: stable(a)vger.kernel.org # 3.13
Cc: Roger Quadros <rogerq(a)kernel.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20250724131206.2211-3-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/phy/ti/phy-omap-usb2.c b/drivers/phy/ti/phy-omap-usb2.c
index c1a0ef979142..c444bb2530ca 100644
--- a/drivers/phy/ti/phy-omap-usb2.c
+++ b/drivers/phy/ti/phy-omap-usb2.c
@@ -363,6 +363,13 @@ static void omap_usb2_init_errata(struct omap_usb *phy)
phy->flags |= OMAP_USB2_DISABLE_CHRG_DET;
}
+static void omap_usb2_put_device(void *_dev)
+{
+ struct device *dev = _dev;
+
+ put_device(dev);
+}
+
static int omap_usb2_probe(struct platform_device *pdev)
{
struct omap_usb *phy;
@@ -373,6 +380,7 @@ static int omap_usb2_probe(struct platform_device *pdev)
struct device_node *control_node;
struct platform_device *control_pdev;
const struct usb_phy_data *phy_data;
+ int ret;
phy_data = device_get_match_data(&pdev->dev);
if (!phy_data)
@@ -423,6 +431,11 @@ static int omap_usb2_probe(struct platform_device *pdev)
return -EINVAL;
}
phy->control_dev = &control_pdev->dev;
+
+ ret = devm_add_action_or_reset(&pdev->dev, omap_usb2_put_device,
+ phy->control_dev);
+ if (ret)
+ return ret;
} else {
if (of_property_read_u32_index(node,
"syscon-phy-power", 1,
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 8d63c83d8eb922f6c316320f50c82fa88d099bea
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091723-stack-cargo-2b1d@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8d63c83d8eb922f6c316320f50c82fa88d099bea Mon Sep 17 00:00:00 2001
From: Alan Stern <stern(a)rowland.harvard.edu>
Date: Mon, 25 Aug 2025 12:00:22 -0400
Subject: [PATCH] USB: gadget: dummy-hcd: Fix locking bug in RT-enabled kernels
Yunseong Kim and the syzbot fuzzer both reported a problem in
RT-enabled kernels caused by the way dummy-hcd mixes interrupt
management and spin-locking. The pattern was:
local_irq_save(flags);
spin_lock(&dum->lock);
...
spin_unlock(&dum->lock);
... // calls usb_gadget_giveback_request()
local_irq_restore(flags);
The code was written this way because usb_gadget_giveback_request()
needs to be called with interrupts disabled and the private lock not
held.
While this pattern works fine in non-RT kernels, it's not good when RT
is enabled. RT kernels handle spinlocks much like mutexes; in particular,
spin_lock() may sleep. But sleeping is not allowed while local
interrupts are disabled.
To fix the problem, rewrite the code to conform to the pattern used
elsewhere in dummy-hcd and other UDC drivers:
spin_lock_irqsave(&dum->lock, flags);
...
spin_unlock(&dum->lock);
usb_gadget_giveback_request(...);
spin_lock(&dum->lock);
...
spin_unlock_irqrestore(&dum->lock, flags);
This approach satisfies the RT requirements.
Signed-off-by: Alan Stern <stern(a)rowland.harvard.edu>
Cc: stable <stable(a)kernel.org>
Fixes: b4dbda1a22d2 ("USB: dummy-hcd: disable interrupts during req->complete")
Reported-by: Yunseong Kim <ysk(a)kzalloc.com>
Closes: <https://lore.kernel.org/linux-usb/5b337389-73b9-4ee4-a83e-7e82bf5af87a@kzal…>
Reported-by: syzbot+8baacc4139f12fa77909(a)syzkaller.appspotmail.com
Closes: <https://lore.kernel.org/linux-usb/68ac2411.050a0220.37038e.0087.GAE@google.…>
Tested-by: syzbot+8baacc4139f12fa77909(a)syzkaller.appspotmail.com
CC: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
CC: stable(a)vger.kernel.org
Reviewed-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Link: https://lore.kernel.org/r/bb192ae2-4eee-48ee-981f-3efdbbd0d8f0@rowland.harv…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index 21dbfb0b3bac..1cefca660773 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -765,8 +765,7 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
if (!dum->driver)
return -ESHUTDOWN;
- local_irq_save(flags);
- spin_lock(&dum->lock);
+ spin_lock_irqsave(&dum->lock, flags);
list_for_each_entry(iter, &ep->queue, queue) {
if (&iter->req != _req)
continue;
@@ -776,15 +775,16 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
retval = 0;
break;
}
- spin_unlock(&dum->lock);
if (retval == 0) {
dev_dbg(udc_dev(dum),
"dequeued req %p from %s, len %d buf %p\n",
req, _ep->name, _req->length, _req->buf);
+ spin_unlock(&dum->lock);
usb_gadget_giveback_request(_ep, _req);
+ spin_lock(&dum->lock);
}
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&dum->lock, flags);
return retval;
}
Fix a memory leak in netpoll and introduce netconsole selftests that
expose the issue when running with kmemleak detection enabled.
This patchset includes a selftest for netpoll with multiple concurrent
users (netconsole + bonding), which simulates the scenario from test[1]
that originally demonstrated the issue allegedly fixed by commit
efa95b01da18 ("netpoll: fix use after free") - a commit that is now
being reverted.
Sending this to "net" branch because this is a fix, and the selftest
might help with the backports validation.
Link: https://lore.kernel.org/lkml/96b940137a50e5c387687bb4f57de8b0435a653f.14048… [1]
Signed-off-by: Breno Leitao <leitao(a)debian.org>
---
Changes in v4:
- Added an additional selftest to test multiple netpoll users in
parallel
- Link to v3: https://lore.kernel.org/r/20250905-netconsole_torture-v3-0-875c7febd316@deb…
Changes in v3:
- This patchset is a merge of the fix and the selftest together as
recommended by Jakub.
Changes in v2:
- Reuse the netconsole creation from lib_netcons.sh. Thus, refactoring
the create_dynamic_target() (Jakub)
- Move the "wait" to after all the messages has been sent.
- Link to v1: https://lore.kernel.org/r/20250902-netconsole_torture-v1-1-03c6066598e9@deb…
---
Breno Leitao (4):
net: netpoll: fix incorrect refcount handling causing incorrect cleanup
selftest: netcons: refactor target creation
selftest: netcons: create a torture test
selftest: netcons: add test for netconsole over bonded interfaces
net/core/netpoll.c | 7 +-
tools/testing/selftests/drivers/net/Makefile | 2 +
.../selftests/drivers/net/lib/sh/lib_netcons.sh | 197 ++++++++++++++++++---
.../selftests/drivers/net/netcons_over_bonding.sh | 76 ++++++++
.../selftests/drivers/net/netcons_torture.sh | 127 +++++++++++++
5 files changed, 384 insertions(+), 25 deletions(-)
---
base-commit: 5e87fdc37f8dc619549d49ba5c951b369ce7c136
change-id: 20250902-netconsole_torture-8fc23f0aca99
Best regards,
--
Breno Leitao <leitao(a)debian.org>
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 a5c98e8b1398534ae1feb6e95e2d3ee5215538ed
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091756-glare-cyclic-9298@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a5c98e8b1398534ae1feb6e95e2d3ee5215538ed Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman(a)linux.intel.com>
Date: Tue, 2 Sep 2025 13:53:05 +0300
Subject: [PATCH] xhci: dbc: Fix full DbC transfer ring after several
reconnects
Pending requests will be flushed on disconnect, and the corresponding
TRBs will be turned into No-op TRBs, which are ignored by the xHC
controller once it starts processing the ring.
If the USB debug cable repeatedly disconnects before ring is started
then the ring will eventually be filled with No-op TRBs.
No new transfers can be queued when the ring is full, and driver will
print the following error message:
"xhci_hcd 0000:00:14.0: failed to queue trbs"
This is a normal case for 'in' transfers where TRBs are always enqueued
in advance, ready to take on incoming data. If no data arrives, and
device is disconnected, then ring dequeue will remain at beginning of
the ring while enqueue points to first free TRB after last cancelled
No-op TRB.
s
Solve this by reinitializing the rings when the debug cable disconnects
and DbC is leaving the configured state.
Clear the whole ring buffer and set enqueue and dequeue to the beginning
of ring, and set cycle bit to its initial state.
Cc: stable(a)vger.kernel.org
Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver")
Signed-off-by: Mathias Nyman <mathias.nyman(a)linux.intel.com>
Link: https://lore.kernel.org/r/20250902105306.877476-3-mathias.nyman@linux.intel…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index d0faff233e3e..63edf2d8f245 100644
--- a/drivers/usb/host/xhci-dbgcap.c
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -462,6 +462,25 @@ static void xhci_dbc_ring_init(struct xhci_ring *ring)
xhci_initialize_ring_info(ring);
}
+static int xhci_dbc_reinit_ep_rings(struct xhci_dbc *dbc)
+{
+ struct xhci_ring *in_ring = dbc->eps[BULK_IN].ring;
+ struct xhci_ring *out_ring = dbc->eps[BULK_OUT].ring;
+
+ if (!in_ring || !out_ring || !dbc->ctx) {
+ dev_warn(dbc->dev, "Can't re-init unallocated endpoints\n");
+ return -ENODEV;
+ }
+
+ xhci_dbc_ring_init(in_ring);
+ xhci_dbc_ring_init(out_ring);
+
+ /* set ep context enqueue, dequeue, and cycle to initial values */
+ xhci_dbc_init_ep_contexts(dbc);
+
+ return 0;
+}
+
static struct xhci_ring *
xhci_dbc_ring_alloc(struct device *dev, enum xhci_ring_type type, gfp_t flags)
{
@@ -885,7 +904,7 @@ static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
dev_info(dbc->dev, "DbC cable unplugged\n");
dbc->state = DS_ENABLED;
xhci_dbc_flush_requests(dbc);
-
+ xhci_dbc_reinit_ep_rings(dbc);
return EVT_DISC;
}
@@ -895,7 +914,7 @@ static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
writel(portsc, &dbc->regs->portsc);
dbc->state = DS_ENABLED;
xhci_dbc_flush_requests(dbc);
-
+ xhci_dbc_reinit_ep_rings(dbc);
return EVT_DISC;
}
Hi,
I would like to request backport of these two commits to 6.6.y:
b5b4287accd702f562a49a60b10dbfaf7d40270f ("riscv: mm: Use hint address in mmap if available")
2116988d5372aec51f8c4fb85bf8e305ecda47a0 ("riscv: mm: Do not restrict mmap address based on hint")
Together, they amount to disabling arch_get_mmap_end and
arch_get_mmap_base for riscv.
I would like to note that the first patch conflicts with commit
724103429a2d ("riscv: mm: Fixup compat arch_get_mmap_end") in the stable
linux-6.6.y branch. STACK_TOP_MAX should end up as TASK_SIZE, *not*
TASK_SIZE_64.
Thanks,
Vivian "dramforever" Wang
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.
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")
cc: stable(a)vger.kernel.org # v6.6
Signed-off-by: Donet Tom <donettom(a)linux.ibm.com>
---
include/linux/ksm.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
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)
--
2.51.0