From: Steven Rostedt <rostedt(a)goodmis.org>
The fix to use a per CPU buffer to read user space tested only the writes
to trace_marker. But it appears that the selftests are missing tests to
the trace_maker_raw file. The trace_maker_raw file is used by applications
that writes data structures and not strings into the file, and the tools
read the raw ring buffer to process the structures it writes.
The fix that reads the per CPU buffers passes the new per CPU buffer to
the trace_marker file writes, but the update to the trace_marker_raw write
read the data from user space into the per CPU buffer, but then still used
then passed the user space address to the function that records the data.
Pass in the per CPU buffer and not the user space address.
TODO: Add a test to better test trace_marker_raw.
Cc: stable(a)vger.kernel.org
Cc: Masami Hiramatsu <mhiramat(a)kernel.org>
Cc: Mark Rutland <mark.rutland(a)arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Link: https://lore.kernel.org/20251011035243.386098147@kernel.org
Fixes: 64cf7d058a00 ("tracing: Have trace_marker use per-cpu data to read user space")
Reported-by: syzbot+9a2ede1643175f350105(a)syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68e973f5.050a0220.1186a4.0010.GAE@google.com/
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0fd582651293..bbb89206a891 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7497,12 +7497,12 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
if (tr == &global_trace) {
guard(rcu)();
list_for_each_entry_rcu(tr, &marker_copies, marker_list) {
- written = write_raw_marker_to_buffer(tr, ubuf, cnt);
+ written = write_raw_marker_to_buffer(tr, buf, cnt);
if (written < 0)
break;
}
} else {
- written = write_raw_marker_to_buffer(tr, ubuf, cnt);
+ written = write_raw_marker_to_buffer(tr, buf, cnt);
}
return written;
--
2.51.0
The patch titled
Subject: mm: prevent poison consumption when splitting THP
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-prevent-poison-consumption-when-splitting-thp.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Qiuxu Zhuo <qiuxu.zhuo(a)intel.com>
Subject: mm: prevent poison consumption when splitting THP
Date: Sat, 11 Oct 2025 15:55:19 +0800
When performing memory error injection on a THP (Transparent Huge Page)
mapped to userspace on an x86 server, the kernel panics with the following
trace. The expected behavior is to terminate the affected process instead
of panicking the kernel, as the x86 Machine Check code can recover from an
in-userspace #MC.
mce: [Hardware Error]: CPU 0: Machine Check Exception: f Bank 3: bd80000000070134
mce: [Hardware Error]: RIP 10:<ffffffff8372f8bc> {memchr_inv+0x4c/0xf0}
mce: [Hardware Error]: TSC afff7bbff88a ADDR 1d301b000 MISC 80 PPIN 1e741e77539027db
mce: [Hardware Error]: PROCESSOR 0:d06d0 TIME 1758093249 SOCKET 0 APIC 0 microcode 80000320
mce: [Hardware Error]: Run the above through 'mcelog --ascii'
mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel
Kernel panic - not syncing: Fatal local machine check
The root cause of this panic is that handling a memory failure triggered
by an in-userspace #MC necessitates splitting the THP. The splitting
process employs a mechanism, implemented in
try_to_map_unused_to_zeropage(), which reads the sub-pages of the THP to
identify zero-filled pages. However, reading the sub-pages results in a
second in-kernel #MC, occurring before the initial memory_failure()
completes, ultimately leading to a kernel panic. See the kernel panic
call trace on the two #MCs.
First Machine Check occurs // [1]
memory_failure() // [2]
try_to_split_thp_page()
split_huge_page()
split_huge_page_to_list_to_order()
__folio_split() // [3]
remap_page()
remove_migration_ptes()
remove_migration_pte()
try_to_map_unused_to_zeropage() // [4]
memchr_inv() // [5]
Second Machine Check occurs // [6]
Kernel panic
[1] Triggered by accessing a hardware-poisoned THP in userspace, which is
typically recoverable by terminating the affected process.
[2] Call folio_set_has_hwpoisoned() before try_to_split_thp_page().
[3] Pass the RMP_USE_SHARED_ZEROPAGE remap flag to remap_page().
[4] Try to map the unused THP to zeropage.
[5] Re-access sub-pages of the hw-poisoned THP in the kernel.
[6] Triggered in-kernel, leading to a panic kernel.
In Step[2], memory_failure() sets the poisoned flag on the sub-page of the
THP by TestSetPageHWPoison() before calling try_to_split_thp_page().
As suggested by David Hildenbrand, fix this panic by not accessing to the
poisoned sub-page of the THP during zeropage identification, while
continuing to scan unaffected sub-pages of the THP for possible zeropage
mapping. This prevents a second in-kernel #MC that would cause kernel
panic in Step[4].
[ Credits to Andrew Zaborowski <andrew.zaborowski(a)intel.com> for his
original fix that prevents passing the RMP_USE_SHARED_ZEROPAGE flag
to remap_page() in Step[3] if the THP has the has_hwpoisoned flag set,
avoiding access to the entire THP for zero-page identification. ]
Link: https://lkml.kernel.org/r/20251011075520.320862-1-qiuxu.zhuo@intel.com
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo(a)intel.com>
Reported-by: Farrah Chen <farrah.chen(a)intel.com>
Suggested-by: David Hildenbrand <david(a)redhat.com>
Tested-by: Farrah Chen <farrah.chen(a)intel.com>
Tested-by: Qiuxu Zhuo <qiuxu.zhuo(a)intel.com>
Acked-by: Lance Yang <lance.yang(a)linux.dev>
Cc: Baolin Wang <baolin.wang(a)linux.alibaba.com>
Cc: Barry Song <baohua(a)kernel.org>
Cc: Dev Jain <dev.jain(a)arm.com>
Cc: Jiaqi Yan <jiaqiyan(a)google.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: "Luck, Tony" <tony.luck(a)intel.com>
Cc: Mariano Pache <npache(a)redhat.com>
Cc: Miaohe Lin <linmiaohe(a)huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi(a)gmail.com>
Cc: Ryan Roberts <ryan.roberts(a)arm.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/huge_memory.c | 3 +++
mm/migrate.c | 3 ++-
2 files changed, 5 insertions(+), 1 deletion(-)
--- a/mm/huge_memory.c~mm-prevent-poison-consumption-when-splitting-thp
+++ a/mm/huge_memory.c
@@ -4109,6 +4109,9 @@ static bool thp_underused(struct folio *
if (khugepaged_max_ptes_none == HPAGE_PMD_NR - 1)
return false;
+ if (folio_contain_hwpoisoned_page(folio))
+ return false;
+
for (i = 0; i < folio_nr_pages(folio); i++) {
if (pages_identical(folio_page(folio, i), ZERO_PAGE(0))) {
if (++num_zero_pages > khugepaged_max_ptes_none)
--- a/mm/migrate.c~mm-prevent-poison-consumption-when-splitting-thp
+++ a/mm/migrate.c
@@ -301,8 +301,9 @@ static bool try_to_map_unused_to_zeropag
struct page *page = folio_page(folio, idx);
pte_t newpte;
- if (PageCompound(page))
+ if (PageCompound(page) || PageHWPoison(page))
return false;
+
VM_BUG_ON_PAGE(!PageAnon(page), page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(pte_present(old_pte), page);
_
Patches currently in -mm which might be from qiuxu.zhuo(a)intel.com are
mm-prevent-poison-consumption-when-splitting-thp.patch
This fixes a couple of different problems, that can cause RTC (alarm)
irqs to be missing when generating UIE interrupts.
The first commit fixes a long-standing problem, which has been
documented in a comment since 2010. This fixes a race that could cause
UIE irqs to stop being generated, which was easily reproduced by
timing the use of RTC_UIE_ON ioctl with the seconds tick in the RTC.
The last commit ensures that RTC (alarm) irqs are enabled whenever
RTC_UIE_ON ioctl is used.
The driver specific commits avoids kernel warnings about unbalanced
enable_irq/disable_irq, which gets triggered on first RTC_UIE_ON with
the last commit. Before this series, the same warning should be seen
on initial RTC_AIE_ON with those drivers.
Signed-off-by: Esben Haabendal <esben(a)geanix.com>
---
Changes in v2:
- Dropped patch for rtc-st-lpc driver.
- Link to v1: https://lore.kernel.org/r/20241203-rtc-uie-irq-fixes-v1-0-01286ecd9f3f@gean…
---
Esben Haabendal (5):
rtc: interface: Fix long-standing race when setting alarm
rtc: isl12022: Fix initial enable_irq/disable_irq balance
rtc: cpcap: Fix initial enable_irq/disable_irq balance
rtc: tps6586x: Fix initial enable_irq/disable_irq balance
rtc: interface: Ensure alarm irq is enabled when UIE is enabled
drivers/rtc/interface.c | 27 +++++++++++++++++++++++++++
drivers/rtc/rtc-cpcap.c | 1 +
drivers/rtc/rtc-isl12022.c | 1 +
drivers/rtc/rtc-tps6586x.c | 1 +
4 files changed, 30 insertions(+)
---
base-commit: 82f2b0b97b36ee3fcddf0f0780a9a0825d52fec3
change-id: 20241203-rtc-uie-irq-fixes-f2838782d0f8
Best regards,
--
Esben Haabendal <esben(a)geanix.com>
There're several different actual hardwares sold by Huawei, using the
same USB ID 12d1:3a07.
The first one we found, having a volume control named "Headset Playback
Volume", reports a min value -15360, and will mute iff setting it to
-15360. It can be simply fixed by quirk flag MIXER_PLAYBACK_MIN_MUTE,
which we have already submitted previously.[1]
The second one we found today, having a volume control named "PCM
Playback Volume", reports its min -11520 and res 256, and will mute
when less than -11008. Because of the already existing quirk flag, we
can just set its min to -11264, and the new minimum value will still
not be available to userspace, so that userspace's minimum will be the
correct -11008.
1. https://lore.kernel.org/all/20250903-sound-v1-3-d4ca777b8512@uniontech.com/
Tested-by: Guoli An <anguoli(a)uniontech.com>
Signed-off-by: Cryolitia PukNgae <cryolitia.pukngae(a)linux.dev>
---
sound/usb/mixer.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 34bcbfd8b54e66abc0229eefd354eb7bc4c01576..ae412e651faf905c9f7d600de8e19c51995cd3f9 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1189,6 +1189,13 @@ static void volume_control_quirks(struct usb_mixer_elem_info *cval,
cval->min = -14208; /* Mute under it */
}
break;
+ case USB_ID(0x12d1, 0x3a07): /* Huawei Technologies Co., Ltd. CM-Q3 */
+ if (!strcmp(kctl->id.name, "PCM Playback Volume")) {
+ usb_audio_info(chip,
+ "set volume quirk for Huawei Technologies Co., Ltd. CM-Q3\n");
+ cval->min = -11264; /* Mute under it */
+ }
+ break;
}
}
---
base-commit: 7e9827afc78073096149cf3565ba668fe2ef4831
change-id: 20251011-sound_quirk-6a8326325451
Best regards,
--
Cryolitia PukNgae <cryolitia.pukngae(a)linux.dev>
The __component_match_add function may assign the 'matchptr' pointer
the value ERR_PTR(-ENOMEM), which will subsequently be dereferenced.
The call stack leading to the error looks like this:
hda_component_manager_init
|-> component_match_add
|-> component_match_add_release
|-> __component_match_add ( ... ,**matchptr, ... )
|-> *matchptr = ERR_PTR(-ENOMEM); // assign
|-> component_master_add_with_match( ... match)
|-> component_match_realloc(match, match->num); // dereference
Add IS_ERR() check to prevent the crash.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: ae7abe36e352 ("ALSA: hda/realtek: Add CS35L41 support for Thinkpad laptops")
Cc: stable(a)vger.kernel.org
Signed-off-by: Denis Arefev <arefev(a)swemel.ru>
---
V1 -> V2:
Changed tag Fixes
Add print to log an error it as Stefan Binding <sbinding(a)opensource.cirrus.com> suggested
sound/hda/codecs/side-codecs/hda_component.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/sound/hda/codecs/side-codecs/hda_component.c b/sound/hda/codecs/side-codecs/hda_component.c
index bcf47a301697..603a9b8ca481 100644
--- a/sound/hda/codecs/side-codecs/hda_component.c
+++ b/sound/hda/codecs/side-codecs/hda_component.c
@@ -174,6 +174,10 @@ int hda_component_manager_init(struct hda_codec *cdc,
sm->match_str = match_str;
sm->index = i;
component_match_add(dev, &match, hda_comp_match_dev_name, sm);
+ if (IS_ERR(match)) {
+ codec_err(cdc, "Fail to add component %ld\n", PTR_ERR(match));
+ return PTR_ERR(match);
+ }
}
ret = component_master_add_with_match(dev, ops, match);
--
2.43.0
Return value of a function acpi_evaluate_dsm() is dereferenced without
checking for NULL, but it is usually checked for this function.
acpi_evaluate_dsm() may return NULL, when acpi_evaluate_object() returns
acpi_status other than ACPI_SUCCESS, so add a check to prevent the crach.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 447106e92a0c ("ALSA: hda: cs35l41: Support mute notifications for CS35L41 HDA")
Cc: stable(a)vger.kernel.org
Signed-off-by: Denis Arefev <arefev(a)swemel.ru>
---
sound/hda/codecs/side-codecs/cs35l41_hda.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/hda/codecs/side-codecs/cs35l41_hda.c b/sound/hda/codecs/side-codecs/cs35l41_hda.c
index 37f2cdc8ce82..890ddb8cc66c 100644
--- a/sound/hda/codecs/side-codecs/cs35l41_hda.c
+++ b/sound/hda/codecs/side-codecs/cs35l41_hda.c
@@ -1426,6 +1426,8 @@ static int cs35l41_get_acpi_mute_state(struct cs35l41_hda *cs35l41, acpi_handle
if (cs35l41_dsm_supported(handle, CS35L41_DSM_GET_MUTE)) {
ret = acpi_evaluate_dsm(handle, &guid, 0, CS35L41_DSM_GET_MUTE, NULL);
+ if (!ret)
+ return -EINVAL;
mute = *ret->buffer.pointer;
dev_dbg(cs35l41->dev, "CS35L41_DSM_GET_MUTE: %d\n", mute);
}
--
2.43.0
In exfat_nls_to_ucs2(), if there is no NLS loss and the char-to-ucs2
conversion is successfully completed, the variable "i" will have the same
value as len.
However, exfat_nls_to_ucs2() checks p_cstring[i] to determine whether nls
is lost immediately after the while loop ends, so if len is FSLABEL_MAX,
"i" will also be FSLABEL_MAX immediately after the while loop ends,
resulting in an out-of-bounds read of 1 byte from the p_cstring stack
memory.
Therefore, to prevent this and properly determine whether nls has been
lost, it should be modified to check if "i" and len are equal, rather than
dereferencing p_cstring.
Cc: <stable(a)vger.kernel.org>
Reported-by: syzbot+98cc76a76de46b3714d4(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=98cc76a76de46b3714d4
Fixes: 370e812b3ec1 ("exfat: add nls operations")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
---
fs/exfat/nls.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c
index 8243d94ceaf4..de06abe426d7 100644
--- a/fs/exfat/nls.c
+++ b/fs/exfat/nls.c
@@ -616,7 +616,7 @@ static int exfat_nls_to_ucs2(struct super_block *sb,
unilen++;
}
- if (p_cstring[i] != '\0')
+ if (i != len)
lossy |= NLS_NAME_OVERLEN;
*uniname = '\0';
--
From: Steven Rostedt <rostedt(a)goodmis.org>
The fix to use a per CPU buffer to read user space tested only the writes
to trace_marker. But it appears that the selftests are missing tests to
the trace_maker_raw file. The trace_maker_raw file is used by applications
that writes data structures and not strings into the file, and the tools
read the raw ring buffer to process the structures it writes.
The fix that reads the per CPU buffers passes the new per CPU buffer to
the trace_marker file writes, but the update to the trace_marker_raw write
read the data from user space into the per CPU buffer, but then still used
then passed the user space address to the function that records the data.
Pass in the per CPU buffer and not the user space address.
TODO: Add a test to better test trace_marker_raw.
Cc: stable(a)vger.kernel.org
Fixes: 64cf7d058a00 ("tracing: Have trace_marker use per-cpu data to read user space")
Reported-by: syzbot+9a2ede1643175f350105(a)syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68e973f5.050a0220.1186a4.0010.GAE@google.com/
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0fd582651293..bbb89206a891 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7497,12 +7497,12 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
if (tr == &global_trace) {
guard(rcu)();
list_for_each_entry_rcu(tr, &marker_copies, marker_list) {
- written = write_raw_marker_to_buffer(tr, ubuf, cnt);
+ written = write_raw_marker_to_buffer(tr, buf, cnt);
if (written < 0)
break;
}
} else {
- written = write_raw_marker_to_buffer(tr, ubuf, cnt);
+ written = write_raw_marker_to_buffer(tr, buf, cnt);
}
return written;
--
2.51.0