Linux: >> Linux Kernel >> 6.16.2 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
drivers/base/memory: fix memory block reference leak in poison accounting
memblk_nr_poison_inc() and memblk_nr_poison_sub() look up a memory block
via find_memory_block_by_id(), which acquires a reference to the memory
block device.
Both helpers use the returned memory block without dropping that
reference, leaking the device reference on each successful lookup. Drop
the reference after updating nr_hwpoison.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
efi: Allocate runtime workqueue before ACPI init
Since commit
5894cf571e14 ("acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers")
ACPI PRM calls are delegated to a workqueue which runs in a kernel
thread, making it easier to detect and mitigate faulting memory accesses
performed by the firmware.
Rafael reports that such PRM accesses may occur before efisubsys_init()
executes, which is where the workqueue is allocated, leading to NULL
pointer dereferences. Since acpi_init() [which triggers the early PRM
accesses] executes as a subsys_initcall() as well, and has its own
dependencies that may be sensitive to initcall ordering, deferring
acpi_init() is not an option.
So instead, split off the workqueue allocation into its own postcore
initcall, as this is the only missing piece to allow EFI runtime calls
to be made. This ensures that EFI runtime call (including PRM calls) are
accessible to all code running at subsys_initcall() level.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs-schemes: call missing mem_cgroup_iter_break()
damon_sysfs_memcg_path_to_id() breaks mem_cgroup_iter() loop without
calling mem_cgroup_iter_break(). This leaks the cgroup reference. Fix
the issue by calling mem_cgroup_iter_break() before the break.
The issue was discovered [1] by Sashiko.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
sysfs: don't remove existing directory on update failure
When sysfs_update_group() is called for a named group and create_files()
fails (e.g. -ENOMEM), internal_create_group() calls kernfs_remove(kn) on
the group directory. In the update path, kn was obtained via
kernfs_find_and_get() and refers to a directory that already existed
before this call. Removing it silently destroys a sysfs group that the
caller did not create.
Only remove the directory if we created it ourselves. On update failure
the directory remains as it is left empty by remove_files() inside
create_files(), but can be repopulated by a retry.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: bnep: Fix UAF read of dev->name
bnep_add_connection() needs to keep holding the bnep_session_sem while
reading dev->name (just like bnep_get_connlist() does); otherwise the
bnep_session() thread can concurrently free the net_device, which can for
example be triggered by a concurrent bnep_del_connection().
(This UAF is fairly uninteresting from a security perspective;
calling bnep_add_connection() requires passing a capable(CAP_NET_ADMIN)
check. It also requires completely tearing down a netdev during a fairly
tight race window.)
CVSS Score
8.8
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
net: wwan: iosm: fix potential memory leaks in ipc_imem_init()
The memory allocated in ipc_protocol_init() is not freed on the error
paths that follow in ipc_imem_init(). Fix that by calling the
corresponding release function ipc_protocol_deinit() in the error path.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
mm/memory_hotplug: fix memory block reference leak on remove
Patch series "mm: Fix memory block leaks and locking", v2.
This series fixes two memory block device reference leaks and one locking
issue around the per-memory_block hwpoison counter.
This patch (of 2):
remove_memory_blocks_and_altmaps() looks up each memory block with
find_memory_block(), which acquires a reference to the memory block
device.
That reference is never dropped on this path, resulting in a leaked device
reference when removing memory blocks and their altmaps. Drop the
reference after retrieving mem->altmap and clearing mem->altmap, before
removing the memory block device.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mld: stop TX during firmware restart
When iwlwifi firmware crashes (e.g., NMI_INTERRUPT_UNKNOWN on Intel
BE201/Wi-Fi 7), iwl_mld_nic_error() sets mld->fw_status.in_hw_restart
to true. However, iwl_mld_tx_from_txq() does not check this flag before
dequeuing frames from mac80211 and pushing them to the transport layer.
Since the firmware is dead, iwl_trans_tx() returns -EIO for each frame,
which then gets freed immediately. Under high-throughput conditions
(e.g., Tailscale UDP traffic or active SSH sessions), this creates a
tight dequeue-send-fail-free loop that wastes CPU cycles and generates
rapid skb allocation churn, leading to memory pressure from slab
fragmentation.
The RX path already has this guard (iwl_mld_rx_mpdu checks
in_hw_restart at rx.c:1906), and so does the TXQ allocation worker
(iwl_mld_add_txqs_wk at tx.c:156). Add the same guard to
iwl_mld_tx_from_txq() to stop all TX during firmware restart.
Frames left in mac80211's TXQs are naturally drained after restart
completes, when queue reallocation triggers iwl_mld_tx_from_txq()
via iwl_mld_add_txq_list(), or when new upper-layer traffic invokes
wake_tx_queue.
Tested on ASUS Zenbook 14 UX3405CA with Intel BE201 (Wi-Fi 7) on
kernel 6.19.5 where the firmware crashes approximately every 10-15
minutes under Tailscale traffic.
CVSS Score
7.5
EPSS Score
0.003
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
idpf: fix read_dev_clk_lock spinlock init in idpf_ptp_init()
In idpf_ptp_init(), read_dev_clk_lock is initialized after
ptp_schedule_worker() had already been called (and after
idpf_ptp_settime64() could reach the lock). The PTP aux worker
fires immediately upon scheduling and can call into
idpf_ptp_read_src_clk_reg_direct(), which takes
spin_lock(&ptp->read_dev_clk_lock) on an uninitialized lock, triggering
the lockdep "non-static key" warning:
[12973.796587] idpf 0000:83:00.0: Device HW Reset initiated
[12974.094507] INFO: trying to register non-static key.
...
[12974.097208] Call Trace:
[12974.097213] <TASK>
[12974.097218] dump_stack_lvl+0x93/0xe0
[12974.097234] register_lock_class+0x4c4/0x4e0
[12974.097249] ? __lock_acquire+0x427/0x2290
[12974.097259] __lock_acquire+0x98/0x2290
[12974.097272] lock_acquire+0xc6/0x310
[12974.097281] ? idpf_ptp_read_src_clk_reg+0xb7/0x150 [idpf]
[12974.097311] ? lockdep_hardirqs_on_prepare+0xde/0x190
[12974.097318] ? finish_task_switch.isra.0+0xd2/0x350
[12974.097330] ? __pfx_ptp_aux_kworker+0x10/0x10 [ptp]
[12974.097343] _raw_spin_lock+0x30/0x40
[12974.097353] ? idpf_ptp_read_src_clk_reg+0xb7/0x150 [idpf]
[12974.097373] idpf_ptp_read_src_clk_reg+0xb7/0x150 [idpf]
[12974.097391] ? kthread_worker_fn+0x88/0x3d0
[12974.097404] ? kthread_worker_fn+0x4e/0x3d0
[12974.097411] idpf_ptp_update_cached_phctime+0x26/0x120 [idpf]
[12974.097428] ? _raw_spin_unlock_irq+0x28/0x50
[12974.097436] idpf_ptp_do_aux_work+0x15/0x20 [idpf]
[12974.097454] ptp_aux_kworker+0x20/0x40 [ptp]
[12974.097464] kthread_worker_fn+0xd5/0x3d0
[12974.097474] ? __pfx_kthread_worker_fn+0x10/0x10
[12974.097482] kthread+0xf4/0x130
[12974.097489] ? __pfx_kthread+0x10/0x10
[12974.097498] ret_from_fork+0x32c/0x410
[12974.097512] ? __pfx_kthread+0x10/0x10
[12974.097519] ret_from_fork_asm+0x1a/0x30
[12974.097540] </TASK>
Move the call to spin_lock_init() up a bit to make sure read_dev_clk_lock
is not touched before it's been initialized.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
netfs, afs: Fix write skipping in dir/link writepages
Fix netfs_write_single() and afs_single_writepages() to better handle a
write that would be skipped due to lock contention and WB_SYNC_NONE by
returning 1 from netfs_write_single() if it skipped and making
afs_single_writepages() skip also. If a skip occurs, the inode must be
re-marked as the VFS may have cleared the mark.
This is really only theoretical for directories in netfs_write_single() as
the only path to that is through afs_single_writepages() that takes the
->validate_lock around it, thereby serialising it.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19