| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
kernfs: fix xattr race condition with multiple superblocks
Multiple superblocks with different namespaces can share the same
kernfs_node when kernfs_test_super() finds a matching root but
different namespace. This means multiple inodes from different
superblocks can reference the same kernfs_node->iattr->xattrs
structure.
The VFS layer only holds per-inode locks during xattr operations,
which is insufficient to serialize concurrent xattr modifications on
the shared kernfs_node. This can lead to race conditions in
simple_xattr_set() where the lookup->replace/remove sequence is not
atomic with respect to operations from other superblocks.
Fix this by protecting xattr operations with the existing hashed
kernfs_locks->open_file_mutex[] array, which is already used to
protect per-node open file data. The hashed mutex array provides
scalable per-node serialization (scaled by CPU count, up to 1024 locks
on 32+ CPU systems) with zero memory overhead.
Changes:
- Rename open_file_mutex[] to node_mutex[] to reflect dual purpose
- Add kernfs_node_lock_ptr() and kernfs_node_lock() helpers
- Protect simple_xattr_set() calls in kernfs_xattr_set() and
kernfs_vfs_user_xattr_set() with the hashed mutex
- Update file.c to use new helpers via compatibility wrappers
- Update documentation to explain the extended lock usage |
| Concurrent execution using shared resource with improper synchronization ('race condition') in Windows DNS allows an unauthorized attacker to execute code over a network. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: midi: Serialize output teardown with event_input
event_process_midi() borrows msynth->output_rfile.output and then
passes the substream to dump_midi() and snd_rawmidi_kernel_write()
without synchronizing with the output open/close transition.
midisynth_use() also publishes output_rfile before
snd_rawmidi_output_params() has finished.
The last midisynth_unuse() can therefore release the same rawmidi file
and free substream->runtime before snd_rawmidi_kernel_write1() takes
its runtime buffer reference. That leaves the event_input path using a
stale substream or runtime and can end in a NULL-deref or use-after-free.
Fix this with two pieces of synchronization. Keep a short IRQ-safe
spinlock only for publishing or clearing output_rfile and for pairing
the output snapshot with an snd_use_lock_t reference. Once
event_process_midi() has taken that in-flight reference, it drops the
spinlock before calling snd_seq_dump_var_event(), dump_midi(), or
snd_rawmidi_kernel_write(). midisynth_unuse() now detaches the visible
rawmidi file under the same spinlock, waits for the in-flight writers
to drain, and only then drains and releases the saved file.
midisynth_use() likewise opens into a local snd_rawmidi_file and
publishes it only after snd_rawmidi_output_params() succeeds.
The buggy scenario involves two paths, with each column showing the
order within that path:
event_input path: last unuse path:
1. event_process_midi() snapshots 1. midisynth_unuse() starts
output_rfile.output. tearing down output_rfile.
2. dump_midi() reaches 2. snd_rawmidi_kernel_release()
snd_rawmidi_kernel_write() closes the output file.
before runtime is pinned. 3. close_substream() frees
3. The callback keeps using substream->runtime.
the borrowed substream.
Validation reproduced this kernel report:
KASAN null-ptr-deref in snd_rawmidi_kernel_write1+0x56/0x360
RIP: 0033:0x7fde7dd0837f
RIP: 0010:snd_rawmidi_kernel_write1+0x56/0x360 |
| In the Linux kernel, the following vulnerability has been resolved:
kcm: use WRITE_ONCE() when changing lower socket callbacks
kcm_attach() replaces a live lower TCP socket's sk_data_ready and
sk_write_space callbacks with KCM handlers, and kcm_unattach() restores
them later. Those callback-pointer updates are still plain stores even
though the same fields can be read and invoked concurrently on other
CPUs.
If another CPU observes an older callback snapshot after the live field
has already been restored, callback execution can run with a mismatched
target and sk_user_data state, leading to stale or misdirected wakeups.
Use WRITE_ONCE() for the callback replacement and restore operations so
these shared callback fields follow the same visibility contract already
established by the earlier 4022 fixes. |
| Use after free in Windows Bind Filter Driver allows an authorized attacker to elevate privileges locally. |
| Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally. |
| Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Backup Engine allows an authorized attacker to elevate privileges locally. |
| Nozomi Networks Labs identified a CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in the configuration and process-image management functionality of KUNBUS piControl in version 2.6.2 that allows a local authenticated attacker to trigger use-after-free and invalid pointer dereferences on kernel configuration objects, resulting in kernel memory corruption and denial of service, by issuing concurrent crafted requests through the piControl character device. |
| Nozomi Networks Labs identified a CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in the event notification functionality of KUNBUS piControl in version 2.6.2 that allows a local authenticated attacker to corrupt kernel heap and event-list state and disclose a small amount of adjacent kernel memory, resulting in kernel memory corruption and denial of service, by issuing concurrent crafted requests from multiple threads through the piControl character device. |
| In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix race in unix socket mediation when peer_path is used
The holding a reference to the peer_sk is not enough to ensure access
to the peer sk path. Accessing the path outside of the state lock
allows for a race with unix_release_sock(). Fix this by taking the
state lock and getting a reference to the path under lock.
Ideally for connected sockets we would cache this information so we
don't have to take the lock here. But for now just fix the race. |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix lack of locking around modifications of net->cells_dyn_ino
Fix the lack of locking around modifications of net->cells_dyn_ino by
taking net->cells_lock exclusively. This also requires to cell to be
removed from net->cells_dyn_ino in afs_destroy_cell_work() rather than in
afs_cell_destroy() as the latter runs in RCU cleanup context and sleeping
locks cannot be taken there. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: Fix division by zero in initialize_timer()
A userspace-driven ALSA timer (SND_UTIMER) lets an unprivileged user set
the backing snd_timer's hardware resolution to an arbitrary 64-bit value
via SNDRV_TIMER_IOCTL_CREATE. snd_utimer_create() only rejects zero.
When such a timer is bound to a sequencer queue, initialize_timer()
computes the tick period as
tmr->ticks = 1000000000 / (r * freq);
where r is that user-controlled resolution and freq is the sequencer
update rate in Hz, clamped to MIN_FREQUENCY..MAX_FREQUENCY (10..6250).
A resolution of 2^63 makes the 64-bit product r * freq wrap to zero for
any even freq, including DEFAULT_FREQUENCY (1000), so the division faults
with a divide-by-zero.
The division runs under tmr->lock with interrupts disabled, so the oops
leaves the spinlock held and hangs the CPU. It is reachable by an
unprivileged user with access to /dev/snd/timer and /dev/snd/seq.
Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 7 UID: 1000 PID: 456 Comm: alsa_seq_utimer Not tainted 7.2.0-rc4+
RIP: 0010:initialize_timer.constprop.0+0x20a/0x2d0
snd_seq_timer_start+0x15e/0x2b0
snd_seq_control_queue+0x56f/0xba0
snd_seq_write+0x3e0/0x730
Reject an overflowing product with check_mul_overflow() and fall back to
a single tick, which also avoids feeding a wrapped-but-nonzero divisor
(e.g. 2^63 * 1000 mod 2^64 == 0, or other resolutions wrapping to a small
value) into the period computation. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: sja1105: round up PTP perout pin duration
pin_duration is converted from the user-provided period to SJA1105
clock ticks and is later passed as the cycle_time argument to
future_base_time().
Very small period values may become zero after the conversion,
which can lead to a division by zero in future_base_time().
Round zero pin_duration up to 1 tick so that the smallest unsupported
periods use the minimum non-zero hardware duration instead of passing
zero to future_base_time(). |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (aspeed-g6-pwm-tach) Guard fan RPM calculation against divide-by-zero
Sashiko reports:
In the aspeed-g6-pwm-tacho driver, the aspeed_tach_val_to_rpm() function
calculates the fan RPM using the tachometer value. However, it does not
check if the tachometer value is zero before performing the division.
If the hardware reports a tachometer value of 0 (which can happen due to
an extremely fast pulse, a stuck edge, or a hardware glitch), the
calculated tach_div evaluates to 0. The subsequent call to do_div() with
tach_div as the divisor triggers a divide-by-zero exception, leading to
a kernel panic.
Check the divisor against zero to fix the problem. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix writethrough to use collection offload
Fix writethrough write to set NETFS_RREQ_OFFLOAD_COLLECTION on the request
so that collection is processed asynchronously rather than only right at
the end - and also so that asynchronous O_SYNC writes get collected at all. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/boot: Validate console=uart8250 baud rate to fix early boot hang
When the baud rate is empty, 0, invalid, or overflows to 0 when stored
as an int, the system will hang during early boot because of a division
by zero in early_serial_init().
Fall back to DEFAULT_BAUD when the resulting baud rate is 0 to prevent
an early system hang. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mwifiex: fix permanently busy scans after multiple roam iterations
In order for the firmware to sleep, the driver has to confirm a
previously received sleep request. The normal sequence of evets goes
like this:
EVENT_SLEEP -> adapter->ps_state = PS_STATE_PRE_SLEEP -> sleep-confirm
-> SLEEP -> EVENT_AWAKE -> AWAKE.
Before sending the sleep-confirm command, the driver must make sure
there are no commands either running or waiting to be completed.
mwifiex_ret_802_11_associate() unconditionally sets
ps_state = PS_STATE_AWAKE when it processes the association command
response, outside of the normal powersave management flow. If
EVENT_SLEEP arrives while the association command is in flight,
ps_state is PRE_SLEEP when the association command response is parsed,
and the forced AWAKE overwrites it. The deferred sleep-confirm is
never sent.
A subsequent scan_start command is correctly acknowledged, but the
firmware doesn't generate scan_result events. The scan request never
finishes, and additional requests from userspace fail with -EBUSY.
After testing on both IW412 and W8997, I could only trigger the bug on
the IW412 and observed the firmwares behave differently. On the IW412
the firmware still sends EVENT_SLEEP while the authentication /
association process is ongoing. A W8997 under the same
conditions seems to suppress power-save for the duration of the
association, so PRE_SLEEP never coincided with the association response
even after extended periods of testing using the loops
described below (>12hours).
On the IW412, the delay between commands that triggers an EVENT_SLEEP
was empirically determined to be ~20ms. This delay can naturally occur
when the driver is outputting debugging information
(debug_mask = 0x00000037), in which situation the busy scans issue is
repeatable while running "test 1)" as described below. If the delay
between commands is less than ~20ms, the firmware stays awake and
the issue was not reproducible running the same test.
The host_mlme=false path also behaves differently. In this case, the
entire authentication / association transaction is executed by one
command (HostCmd_CMD_802_11_ASSOCIATE), and the firmware doesn't emit
EVENT_SLEEP while the command is running.
Remove the assignment so the ps_state is only manipulated in the paths
that are related to powersave event handling and on the main workqueue
for correct sleep confirmation.
The following loop tests were performed (with debugging output enabled):
1) force roaming between two AP's, one 5GHz and one 2.4GHz, same
SSID. Use wpa_cli to trigger the roaming behavior, sleep 2s
between iterations.
2) force a disconnection to AP 1 and a connection to AP 2, test
scan. Use wpa_cli to trigger the connection changes, sleep 2s
between iterations.
Each test ran in each device for at least 3 hours. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: sdhci-esdhc-imx: disable irq during suspend to fix unhandled interrupt
When using WIFI out-of-band wakeup, an "irq xxx: nobody cared" warning
occurs. This happens because the usdhc interrupt is not disabled during
system suspend when device_may_wakeup() returns false.
The sequence of events leading to this issue:
1. System enters suspend without disabling usdhc interrupt
(because device_may_wakeup() returns false for usdhc device)
2. WIFI out-of-band wakeup triggers system resume via GPIO interrupt
3. WIFI sends a Card interrupt before usdhc has fully resumed
4. usdhc is still in runtime suspend state and cannot handle the
interrupt properly
5. The unhandled interrupt triggers "nobody cared" warning
Fix this by unconditionally disabling the usdhc interrupt during suspend
and re-enabling it during resume, regardless of the wakeup capability.
This ensures no interrupts are processed during the suspend/resume
transition. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: atm: ueagle-atm: wait for pre-firmware load in .disconnect()
ueagle-atm uses the asynchronous request_firmware_nowait() in .probe(),
but does not wait for its completion, not even in .disconnect(); so, if the
device is unplugged meanwhile, its teardown runs concurrently with that.
Even though this inconsistency is worth addressing on its own, it has also
triggered several bug reports in syzbot over the years (some auto-closed)
where the firmware sysfs fallback mechanism (CONFIG_FW_LOADER_USER_HELPER)
creates a firmware subdirectory in the device directory during its removal,
which might hit unexpected conditions in kernfs, apparently, depending at
which point the add and remove operations raced. (See links.)
The pattern is:
usb ?-?: Direct firmware load for ueagle-atm/eagle?.fw failed with error -2
usb ?-?: Falling back to sysfs fallback for: ueagle-atm/eagle?.fw
<ERROR>
Call trace:
...
kernfs_create_dir_ns
sysfs_create_dir_ns
create_dir
kobject_add_internal
kobject_add_varg
kobject_add
class_dir_create_and_add
get_device_parent
device_add
fw_load_sysfs_fallback
fw_load_from_user_helper
firmware_fallback_sysfs
_request_firmware
request_firmware_work_func
...
(Some variations are observed, after fw_load_sysfs_fallback(), e.g., [1].)
While the kernfs side is being looked at, the ueagle-atm side can be fixed
by waiting for the pre-firmware load in the .disconnect() handler.
This change has a similar approach to previous work by Andrey Tsygunka [2]
(wait_for_completion() in .disconnect()), but it is relatively different in
design/implementation; using the Originally-by tag for credit assignment.
This has been tested with:
- synthetic reproducer to check the error path;
- USB gadget (virtual device) to check the firmware upload path;
- QEMU device emulator to check the device ID re-enumeration path;
(The latter two were written by Claude; no other code/text in this commit.)
Links (year first reported):
2025 https://syzbot.org/bug?extid=ce1e5a1b4e086b43e56d
2025 https://syzbot.org/bug?extid=9af8471255ac36e34fd4
2024 https://syzbot.org/bug?extid=306212936b13e520679d
2023 https://syzkaller.appspot.com/bug?extid=457452d30bcdda75ead2
2022 https://syzbot.org/bug?extid=782984d6f1701b526edb
2021 https://syzbot.org/bug?id=f3f221579f4ef7e9691281f3c6f56c05f83e8490
2021 https://syzbot.org/bug?id=84d86f0d71394829df6fc53daf6642c045983881
2021 https://syzbot.org/bug?id=3302dc1c0e2b9c94f2e8edb404eabc9267bc6f90
[1] https://syzkaller.appspot.com/bug?extid=457452d30bcdda75ead2
[2] https://lore.kernel.org/lkml/20250410093146.3776801-2-aitsygunka@yandex.ru/ |
| In the Linux kernel, the following vulnerability has been resolved:
vduse: Fix race in vduse_dev_msg_sync and vduse_dev_read_iter
There is one race case in vduse_dev_msg_sync and vduse_dev_read_iter:
vduse_dev_read_iter():
lock(msg_lock);
dequeue_msg(send_list);
unlock(msg_lock);
vduse_dev_msg_sync():
wait_timeout() finish
lock(msg_lock);
check msg->complete is false
list_del(msg); <- double list_del() crash!
To fix this case, we shall ensure vduse_msg is on send_list or recv_list
outside the msg_lock critical section. |
