The local variable 'sensitivity' was never clamped to 0 or
POWERSAVE_BIAS_MAX because the return value of clamp() was not used. Fix
this by assigning the clamped value back to 'sensitivity'.
Cc: stable(a)vger.kernel.org
Fixes: 9c5320c8ea8b ("cpufreq: AMD "frequency sensitivity feedback" powersave bias for ondemand governor")
Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev>
---
drivers/cpufreq/amd_freq_sensitivity.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/cpufreq/amd_freq_sensitivity.c b/drivers/cpufreq/amd_freq_sensitivity.c
index 13fed4b9e02b..713ccf24c97d 100644
--- a/drivers/cpufreq/amd_freq_sensitivity.c
+++ b/drivers/cpufreq/amd_freq_sensitivity.c
@@ -76,7 +76,7 @@ static unsigned int amd_powersave_bias_target(struct cpufreq_policy *policy,
sensitivity = POWERSAVE_BIAS_MAX -
(POWERSAVE_BIAS_MAX * (d_reference - d_actual) / d_reference);
- clamp(sensitivity, 0, POWERSAVE_BIAS_MAX);
+ sensitivity = clamp(sensitivity, 0, POWERSAVE_BIAS_MAX);
/* this workload is not CPU bound, so choose a lower freq */
if (sensitivity < od_tuners->powersave_bias) {
--
Thorsten Blum <thorsten.blum(a)linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6 9D84 7336 78FD 8DFE EAD4
The local variable 'curr_energy' was never clamped to
PAC_193X_MIN_POWER_ACC or PAC_193X_MAX_POWER_ACC because the return
value of clamp() was not used. Fix this by assigning the clamped value
back to 'curr_energy'.
Cc: stable(a)vger.kernel.org
Fixes: 0fb528c8255b ("iio: adc: adding support for PAC193x")
Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev>
---
drivers/iio/adc/pac1934.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/pac1934.c b/drivers/iio/adc/pac1934.c
index 48df16509260..256488d3936b 100644
--- a/drivers/iio/adc/pac1934.c
+++ b/drivers/iio/adc/pac1934.c
@@ -665,7 +665,8 @@ static int pac1934_reg_snapshot(struct pac1934_chip_info *info,
/* add the power_acc field */
curr_energy += inc;
- clamp(curr_energy, PAC_193X_MIN_POWER_ACC, PAC_193X_MAX_POWER_ACC);
+ curr_energy = clamp(curr_energy, PAC_193X_MIN_POWER_ACC,
+ PAC_193X_MAX_POWER_ACC);
reg_data->energy_sec_acc[cnt] = curr_energy;
}
--
Thorsten Blum <thorsten.blum(a)linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6 9D84 7336 78FD 8DFE EAD4
The local variable 'val' was never clamped to -75000 or 180000 because
the return value of clamp_val() was not used. Fix this by assigning the
clamped value back to 'val', and use clamp() instead of clamp_val().
Cc: stable(a)vger.kernel.org
Fixes: a557a92e6881 ("net: phy: marvell-88q2xxx: add support for temperature sensor")
Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev>
---
drivers/net/phy/marvell-88q2xxx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/phy/marvell-88q2xxx.c b/drivers/net/phy/marvell-88q2xxx.c
index f3d83b04c953..201dee1a1698 100644
--- a/drivers/net/phy/marvell-88q2xxx.c
+++ b/drivers/net/phy/marvell-88q2xxx.c
@@ -698,7 +698,7 @@ static int mv88q2xxx_hwmon_write(struct device *dev,
switch (attr) {
case hwmon_temp_max:
- clamp_val(val, -75000, 180000);
+ val = clamp(val, -75000, 180000);
val = (val / 1000) + 75;
val = FIELD_PREP(MDIO_MMD_PCS_MV_TEMP_SENSOR3_INT_THRESH_MASK,
val);
--
Thorsten Blum <thorsten.blum(a)linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6 9D84 7336 78FD 8DFE EAD4
Hi,
This Linux kernel patch series introduces support for error recovery for
passthrough PCI devices on System Z (s390x).
Background
----------
For PCI devices on s390x an operating system receives platform specific
error events from firmware rather than through AER.Today for
passthrough/userspace devices, we don't attempt any error recovery and
ignore any error events for the devices. The passthrough/userspace devices
are managed by the vfio-pci driver. The driver does register error handling
callbacks (error_detected), and on an error trigger an eventfd to
userspace. But we need a mechanism to notify userspace
(QEMU/guest/userspace drivers) about the error event.
Proposal
--------
We can expose this error information (currently only the PCI Error Code)
via a device feature. Userspace can then obtain the error information
via VFIO_DEVICE_FEATURE ioctl and take appropriate actions such as driving
a device reset.
This is how a typical flow for passthrough devices to a VM would work:
For passthrough devices to a VM, the driver bound to the device on the host
is vfio-pci. vfio-pci driver does support the error_detected() callback
(vfio_pci_core_aer_err_detected()), and on an PCI error s390x recovery
code on the host will call the vfio-pci error_detected() callback. The
vfio-pci error_detected() callback will notify userspace/QEMU via an
eventfd, and return PCI_ERS_RESULT_CAN_RECOVER. At this point the s390x
error recovery on the host will skip any further action(see patch 6) and
let userspace drive the error recovery.
Once userspace/QEMU is notified, it then injects this error into the VM
so device drivers in the VM can take recovery actions. For example for a
passthrough NVMe device, the VM's OS NVMe driver will access the device.
At this point the VM's NVMe driver's error_detected() will drive the
recovery by returning PCI_ERS_RESULT_NEED_RESET, and the s390x error
recovery in the VM's OS will try to do a reset. Resets are privileged
operations and so the VM will need intervention from QEMU to perform the
reset. QEMU will invoke the VFIO_DEVICE_RESET ioctl to now notify the
host that the VM is requesting a reset of the device. The vfio-pci driver
on the host will then perform the reset on the device to recover it.
Thanks
Farhan
ChangeLog
---------
v5 series https://lore.kernel.org/all/20251113183502.2388-1-alifm@linux.ibm.com/
v5 -> v6
- Rebase on 6.18 + Lukas's PCI: Universal error recoverability of
devices series (https://lore.kernel.org/all/cover.1763483367.git.lukas@wunner.de/)
- Re-work config space accessibility check to pci_dev_save_and_disable() (patch 3).
This avoids saving the config space, in the reset path, if the device's config space is
corrupted or inaccessible.
v4 series https://lore.kernel.org/all/20250924171628.826-1-alifm@linux.ibm.com/
v4 -> v5
- Rebase on 6.18-rc5
- Move bug fixes to the beginning of the series (patch 1 and 2). These patches
were posted as a separate fixes series
https://lore.kernel.org/all/a14936ac-47d6-461b-816f-0fd66f869b0f@linux.ibm.…
- Add matching pci_put_dev() for pci_get_slot() (patch 6).
v3 series https://lore.kernel.org/all/20250911183307.1910-1-alifm@linux.ibm.com/
v3 -> v4
- Remove warn messages for each PCI capability not restored (patch 1)
- Check PCI_COMMAND and PCI_STATUS register for error value instead of device id
(patch 1)
- Fix kernel crash in patch 3
- Added reviewed by tags
- Address comments from Niklas's (patches 4, 5, 7)
- Fix compilation error non s390x system (patch 8)
- Explicitly align struct vfio_device_feature_zpci_err (patch 8)
v2 series https://lore.kernel.org/all/20250825171226.1602-1-alifm@linux.ibm.com/
v2 -> v3
- Patch 1 avoids saving any config space state if the device is in error
(suggested by Alex)
- Patch 2 adds additional check only for FLR reset to try other function
reset method (suggested by Alex).
- Patch 3 fixes a bug in s390 for resetting PCI devices with multiple
functions. Creates a new flag pci_slot to allow per function slot.
- Patch 4 fixes a bug in s390 for resource to bus address translation.
- Rebase on 6.17-rc5
v1 series https://lore.kernel.org/all/20250813170821.1115-1-alifm@linux.ibm.com/
v1 - > v2
- Patches 1 and 2 adds some additional checks for FLR/PM reset to
try other function reset method (suggested by Alex).
- Patch 3 fixes a bug in s390 for resetting PCI devices with multiple
functions.
- Patch 7 adds a new device feature for zPCI devices for the VFIO_DEVICE_FEATURE
ioctl. The ioctl is used by userspace to retriece any PCI error
information for the device (suggested by Alex).
- Patch 8 adds a reset_done() callback for the vfio-pci driver, to
restore the state of the device after a reset.
- Patch 9 removes the pcie check for triggering VFIO_PCI_ERR_IRQ_INDEX.
Farhan Ali (9):
PCI: Allow per function PCI slots
s390/pci: Add architecture specific resource/bus address translation
PCI: Avoid saving config space state if inaccessible
PCI: Add additional checks for flr reset
s390/pci: Update the logic for detecting passthrough device
s390/pci: Store PCI error information for passthrough devices
vfio-pci/zdev: Add a device feature for error information
vfio: Add a reset_done callback for vfio-pci driver
vfio: Remove the pcie check for VFIO_PCI_ERR_IRQ_INDEX
arch/s390/include/asm/pci.h | 29 ++++++++
arch/s390/pci/pci.c | 75 +++++++++++++++++++++
arch/s390/pci/pci_event.c | 107 +++++++++++++++++-------------
drivers/pci/host-bridge.c | 4 +-
drivers/pci/pci.c | 19 +++++-
drivers/pci/slot.c | 25 ++++++-
drivers/vfio/pci/vfio_pci_core.c | 20 ++++--
drivers/vfio/pci/vfio_pci_intrs.c | 3 +-
drivers/vfio/pci/vfio_pci_priv.h | 9 +++
drivers/vfio/pci/vfio_pci_zdev.c | 45 ++++++++++++-
include/linux/pci.h | 1 +
include/uapi/linux/vfio.h | 15 +++++
12 files changed, 291 insertions(+), 61 deletions(-)
--
2.43.0
The macro FAN_FROM_REG evaluates its arguments multiple times. When used
in lockless contexts involving shared driver data, this leads to
Time-of-Check to Time-of-Use (TOCTOU) race conditions, potentially
causing divide-by-zero errors.
Convert the macro to a static function. This guarantees that arguments
are evaluated only once (pass-by-value), preventing the race
conditions.
Additionally, in store_fan_div, move the calculation of the minimum
limit inside the update lock. This ensures that the read-modify-write
sequence operates on consistent data.
Adhere to the principle of minimal changes by only converting macros
that evaluate arguments multiple times and are used in lockless
contexts.
Link: https://lore.kernel.org/all/CALbr=LYJ_ehtp53HXEVkSpYoub+XYSTU8Rg=o1xxMJ8=5z…
Fixes: 9873964d6eb2 ("[PATCH] HWMON: w83791d: New hardware monitoring driver for the Winbond W83791D")
Cc: stable(a)vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02(a)gmail.com>
---
Based on the discussion in the link, I will submit a series of patches to
address TOCTOU issues in the hwmon subsystem by converting macros to
functions or adjusting locking where appropriate.
---
drivers/hwmon/w83791d.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/hwmon/w83791d.c b/drivers/hwmon/w83791d.c
index ace854b370a0..996e36951f9d 100644
--- a/drivers/hwmon/w83791d.c
+++ b/drivers/hwmon/w83791d.c
@@ -218,9 +218,14 @@ static u8 fan_to_reg(long rpm, int div)
return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}
-#define FAN_FROM_REG(val, div) ((val) == 0 ? -1 : \
- ((val) == 255 ? 0 : \
- 1350000 / ((val) * (div))))
+static int fan_from_reg(int val, int div)
+{
+ if (val == 0)
+ return -1;
+ if (val == 255)
+ return 0;
+ return 1350000 / (val * div);
+}
/* for temp1 which is 8-bit resolution, LSB = 1 degree Celsius */
#define TEMP1_FROM_REG(val) ((val) * 1000)
@@ -521,7 +526,7 @@ static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
struct w83791d_data *data = w83791d_update_device(dev); \
int nr = sensor_attr->index; \
return sprintf(buf, "%d\n", \
- FAN_FROM_REG(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \
+ fan_from_reg(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \
}
show_fan_reg(fan);
@@ -585,10 +590,10 @@ static ssize_t store_fan_div(struct device *dev, struct device_attribute *attr,
if (err)
return err;
+ mutex_lock(&data->update_lock);
/* Save fan_min */
- min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
+ min = fan_from_reg(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
- mutex_lock(&data->update_lock);
data->fan_div[nr] = div_to_reg(nr, val);
switch (nr) {
--
2.43.0
The driver_override_show() function reads the driver_override string
without holding the device_lock. However, driver_override_store() uses
driver_set_override(), which modifies and frees the string while holding
the device_lock.
This can result in a concurrent use-after-free if the string is freed
by the store function while being read by the show function.
Fix this by holding the device_lock around the read operation.
Fixes: 1f86a00c1159 ("bus/fsl-mc: add support for 'driver_override' in the mc-bus")
Cc: stable(a)vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02(a)gmail.com>
---
I verified this with a stress test that continuously writes/reads the
attribute. It triggered KASAN and leaked bytes like a0 f4 81 9f a3 ff ff
(likely kernel pointers). Since driver_override is world-readable (0644),
this allows unprivileged users to leak kernel pointers and bypass KASLR.
Similar races were fixed in other buses (e.g., commits 9561475db680 and
91d44c1afc61). Currently, 9 of 11 buses handle this correctly; this patch
fixes one of the remaining two.
---
drivers/bus/fsl-mc/fsl-mc-bus.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 25845c04e562..a97baf2cbcdd 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -202,8 +202,12 @@ static ssize_t driver_override_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+ ssize_t len;
- return sysfs_emit(buf, "%s\n", mc_dev->driver_override);
+ device_lock(dev);
+ len = sysfs_emit(buf, "%s\n", mc_dev->driver_override);
+ device_unlock(dev);
+ return len;
}
static DEVICE_ATTR_RW(driver_override);
--
2.43.0
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To opt-out, reply “Not Interested”.
The patch titled
Subject: ocfs2: fix kernel BUG in ocfs2_find_victim_chain
has been added to the -mm mm-nonmm-unstable branch. Its filename is
ocfs2-fix-kernel-bug-in-ocfs2_find_victim_chain.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-nonmm-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: Prithvi Tambewagh <activprithvi(a)gmail.com>
Subject: ocfs2: fix kernel BUG in ocfs2_find_victim_chain
Date: Mon, 1 Dec 2025 18:37:11 +0530
syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the
`cl_next_free_rec` field of the allocation chain list (next free slot in
the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec)
condition in ocfs2_find_victim_chain() and panicking the kernel.
To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(),
just before calling ocfs2_find_victim_chain(), the code block in it being
executed when either of the following conditions is true:
1. `cl_next_free_rec` is equal to 0, indicating that there are no free
chains in the allocation chain list
2. `cl_next_free_rec` is greater than `cl_count` (the total number of
chains in the allocation chain list)
Either of them being true is indicative of the fact that there are no
chains left for usage.
This is addressed using ocfs2_error(), which prints
the error log for debugging purposes, rather than panicking the kernel.
Link: https://lkml.kernel.org/r/20251201130711.143900-1-activprithvi@gmail.com
Signed-off-by: Prithvi Tambewagh <activprithvi(a)gmail.com>
Reported-by: syzbot+96d38c6e1655c1420a72(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
Tested-by: syzbot+96d38c6e1655c1420a72(a)syzkaller.appspotmail.com
Reviewed-by: Joseph Qi <joseph.qi(a)linux.alibaba.com>
Cc: Mark Fasheh <mark(a)fasheh.com>
Cc: Joel Becker <jlbec(a)evilplan.org>
Cc: Junxiao Bi <junxiao.bi(a)oracle.com>
Cc: Changwei Ge <gechangwei(a)live.cn>
Cc: Jun Piao <piaojun(a)huawei.com>
Cc: Heming Zhao <heming.zhao(a)suse.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/ocfs2/suballoc.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/fs/ocfs2/suballoc.c~ocfs2-fix-kernel-bug-in-ocfs2_find_victim_chain
+++ a/fs/ocfs2/suballoc.c
@@ -1993,6 +1993,16 @@ static int ocfs2_claim_suballoc_bits(str
}
cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
+ if (!le16_to_cpu(cl->cl_next_free_rec) ||
+ le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
+ status = ocfs2_error(ac->ac_inode->i_sb,
+ "Chain allocator dinode %llu has invalid next "
+ "free chain record %u, but only %u total\n",
+ (unsigned long long)le64_to_cpu(fe->i_blkno),
+ le16_to_cpu(cl->cl_next_free_rec),
+ le16_to_cpu(cl->cl_count));
+ goto bail;
+ }
victim = ocfs2_find_victim_chain(cl);
ac->ac_chain = victim;
_
Patches currently in -mm which might be from activprithvi(a)gmail.com are
ocfs2-fix-kernel-bug-in-ocfs2_find_victim_chain.patch