Linux: >> Linux Kernel >> 5.4.148 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
drbd: Balance RCU calls in drbd_adm_dump_devices()
Make drbd_adm_dump_devices() call rcu_read_lock() before
rcu_read_unlock() is called. This has been detected by the Clang
thread-safety analyzer.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
fs/mbcache: cancel shrink work before destroying the cache
mb_cache_destroy() calls shrinker_free() and then frees all cache
entries and the cache itself, but it does not cancel the pending
c_shrink_work work item first.
If mb_cache_entry_create() schedules c_shrink_work via schedule_work()
and the work item is still pending or running when mb_cache_destroy()
runs, mb_cache_shrink_worker() will access the cache after its memory
has been freed, causing a use-after-free.
This is only reachable by a privileged user (root or CAP_SYS_ADMIN)
who can trigger the last put of a mounted ext2/ext4/ocfs2 filesystem.
Cancel the work item with cancel_work_sync() before calling
shrinker_free(), ensuring the worker has finished and will not be
rescheduled before the cache is torn down.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START
omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440).
Later, omfs_make_empty() uses
sbi->s_sys_blocksize - OMFS_DIR_START
as the length argument to memset(). Since s_sys_blocksize is u32,
a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes
an unsigned underflow there, wrapping to a value near 2^32. That drives
a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel
memory far beyond the backing block buffer.
Add the corresponding lower-bound check alongside the existing upper-bound
check in omfs_fill_super(), so that malformed images are rejected during
superblock validation before any filesystem data is processed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER
When protocol sets HCI_PROTO_DEFER, hci_conn_request_evt() calls
hci_connect_cfm(conn) without hdev->lock. Generally hci_connect_cfm()
assumes it is held, and if conn is deleted concurrently -> UAF.
Only SCO and ISO set HCI_PROTO_DEFER and only for defer setup listen,
and HCI_EV_CONN_REQUEST is not generated for ISO. In the non-deferred
listening socket code paths, hci_connect_cfm(conn) is called with
hdev->lock held.
Fix by holding the lock.
CVSS Score
8.8
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ppp: require CAP_NET_ADMIN in target netns for unattached ioctls
/dev/ppp open is currently authorized against file->f_cred->user_ns,
while unattached administrative ioctls operate on current->nsproxy->net_ns.
As a result, a local unprivileged user can create a new user namespace
with CLONE_NEWUSER, gain CAP_NET_ADMIN only in that new user namespace,
and still issue PPPIOCNEWUNIT, PPPIOCATTACH, or PPPIOCATTCHAN against
an inherited network namespace.
Require CAP_NET_ADMIN in the user namespace that owns the target network
namespace before handling unattached PPP administrative ioctls.
This preserves normal pppd operation in the network namespace it is
actually privileged in, while rejecting the userns-only inherited-netns
case.
CVSS Score
8.8
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix OOB in pcpu_init_value
An out-of-bounds read occurs when copying element from a
BPF_MAP_TYPE_CGROUP_STORAGE map to another pcpu map with the
same value_size that is not rounded up to 8 bytes.
The issue happens when:
1. A CGROUP_STORAGE map is created with value_size not aligned to
8 bytes (e.g., 4 bytes)
2. A pcpu map is created with the same value_size (e.g., 4 bytes)
3. Update element in 2 with data in 1
pcpu_init_value assumes that all sources are rounded up to 8 bytes,
and invokes copy_map_value_long to make a data copy, However, the
assumption doesn't stand since there are some cases where the source
may not be rounded up to 8 bytes, e.g., CGROUP_STORAGE, skb->data.
the verifier verifies exactly the size that the source claims, not
the size rounded up to 8 bytes by kernel, an OOB happens when the
source has only 4 bytes while the copy size(4) is rounded up to 8.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
net/rds: Restrict use of RDS/IB to the initial network namespace
Prevent using RDS/IB in network namespaces other than the initial one.
The existing RDS/IB code will not work properly in non-initial network
namespaces.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
dm cache: fix write hang in passthrough mode
The invalidate_remove() function has incomplete logic for handling write
hit bios after cache invalidation. It sets up the remapping for the
overwrite_bio but then drops it immediately without submission, causing
write operations to hang.
Fix by adding a new invalidate_committed() continuation that submits
the remapped writes to the cache origin after metadata commit completes,
while using the overwrite_endio hook to ensure proper completion
sequencing. This maintains existing coherency. Also improve error
handling in invalidate_complete() to preserve the original error status
instead of using bio_io_error() unconditionally.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ASoC: sti: use managed regmap_field allocations
The regmap_field objects allocated at player init are never freed and
may leak resources if the driver is removed.
Switch to devm_regmap_field_alloc() to automatically limit the lifetime
of the allocations the lifetime of the device.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/sun4i: backend: fix error pointer dereference
The function drm_atomic_get_plane_state() can return an error pointer
and is not checked for it. Add error pointer check.
Detected by Smatch:
drivers/gpu/drm/sun4i/sun4i_backend.c:496 sun4i_backend_atomic_check() error:
'plane_state' dereferencing possible ERR_PTR()
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24