Linux: >> Linux Kernel >> 5.14.17 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
In vti6_tnl_lookup(), when an exact match for a tunnel fails,
the code falls back to searching for wildcard tunnels:
- Tunnels matching the packet's local address, with any remote address
wildcard remote).
- Tunnels matching the packet's remote address, with any local address
(wildcard local).
However, vti6 stores all these different types of tunnels in the same
hash table (ip6n->tnls_r_l) prone to hash collisions.
The bug is that the fallback search loops in vti6_tnl_lookup() were
missing checks to ensure that the candidate tunnel actually has
a wildcard address.
CVSS Score
9.8
EPSS Score
0.006
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: reject BR/EDR signaling packets over MTUsig
net/bluetooth/l2cap_core.c:l2cap_sig_channel() accepts BR/EDR
signaling packets up to the channel MTU and dispatches each command
without enforcing the signaling MTU (MTUsig). A Bluetooth BR/EDR peer
within radio range can send a fixed-channel CID 0x0001 packet that is
larger than MTUsig and contains many L2CAP_ECHO_REQ commands before
pairing. In a real-radio stock-kernel run, one 681-byte signaling
packet containing 168 zero-length ECHO_REQ commands made the target
transmit 168 ECHO_RSP frames over about 220 ms.
Impact: a Bluetooth BR/EDR peer within radio range, before pairing, can
force 168 ECHO_RSP frames from one 681-byte fixed-channel signaling
packet containing packed ECHO_REQ commands.
Define Linux's BR/EDR signaling MTU as the spec minimum of 48 bytes and
reject any larger signaling packet with one L2CAP_COMMAND_REJECT_RSP
carrying L2CAP_REJ_MTU_EXCEEDED before any command is dispatched.
The Bluetooth Core spec wording for MTUExceeded says the reject
identifier shall match the first request command in the packet, and
that packets containing only responses shall be silently discarded.
Linux intentionally deviates from that prescription: silently
discarding desynchronizes the peer because the remote stack never
learns its responses were dropped, and locating the first request
command requires walking command headers past MTUsig, i.e. processing
bytes from a packet we have already decided is too large to process.
We therefore always emit one reject and use the identifier from the
first command header, a single fixed-offset byte read.
The unrestricted BR/EDR signaling parser and ECHO_REQ response path both
trace to the initial git import; no later introducing commit is
available for a Fixes tag.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_tunnel: fix use-after-free on object destroy
nft_tunnel_obj_destroy() calls metadata_dst_free() which directly
kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets
that took a reference via dst_hold() in nft_tunnel_obj_eval() and
are still queued (e.g. in a netem qdisc) are left with a dangling
pointer. When these packets are eventually dequeued, dst_release()
operates on freed memory.
Replace metadata_dst_free() with dst_release() so the metadata_dst
is freed only after all references are dropped. The dst subsystem
already handles metadata_dst cleanup in dst_destroy() when
DST_METADATA is set.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: fix krealloc() memory leak
Don't just overwrite the original pointer passed to krealloc()
with its return value without checking latter:
MEM = krealloc(MEM, SZ, GFP);
If krealloc() returns NULL, that erases the pointer
to the still allocated memory, hence leaks this memory.
Instead, use a temporary variable, check it's not NULL
and only then assign it to the original pointer:
TMP = krealloc(MEM, SZ, GFP);
if (!TMP) return;
MEM = TMP;
While on it, use krealloc_array().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
zram: fix use-after-free in zram_bvec_write_partial()
zram_read_page() picks the sync or async backing device read path based on
whether the parent bio is NULL. zram_bvec_write_partial() passes its
parent bio down, so for ZRAM_WB slots the read is dispatched
asynchronously and zram_read_page() returns 0 while the bio is still in
flight. The caller then runs memcpy_from_bvec(), zram_write_page() and
__free_page() on the buffer, leaving the async read to write into a freed
page.
zram_bvec_read_partial() was switched to NULL in commit 4e3c87b9421d
("zram: fix synchronous reads") for the same reason; the write_partial
counterpart was missed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
fuse: limit FUSE_NOTIFY_RETRIEVE to uptodate folios
FUSE_NOTIFY_RETRIEVE must be limited to uptodate folios; !uptodate folios
can contain uninitialized data.
Since FUSE_NOTIFY_RETRIEVE is intended to only return data that is already
in the page cache and not wait for data from the FUSE daemon, treat
!uptodate folios as if they weren't present.
This only has security impact on systems that don't enable automatic
zero-initialization of all page allocations via
CONFIG_INIT_ON_ALLOC_DEFAULT_ON or init_on_alloc=1.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
net: phonet: free phonet_device after RCU grace period
phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.
Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: Fix NULL pointer dereference in rpmsg callback
A NULL pointer dereference was observed on Hawi at boot when the DSP
sends a glink message before fastrpc_rpmsg_probe() has completed
initialization:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000178
pc : _raw_spin_lock_irqsave+0x34/0x8c
lr : fastrpc_rpmsg_callback+0x3c/0xcc [fastrpc]
...
Call trace:
_raw_spin_lock_irqsave+0x34/0x8c (P)
fastrpc_rpmsg_callback+0x3c/0xcc [fastrpc]
qcom_glink_native_rx+0x538/0x6a4
qcom_glink_smem_intr+0x14/0x24 [qcom_glink_smem]
The faulting address 0x178 corresponds to the lock variable inside
struct fastrpc_channel_ctx, confirming that cctx is NULL when
fastrpc_rpmsg_callback() attempts to take the spinlock.
There are two issues here. First, dev_set_drvdata() is called before
spin_lock_init() and idr_init(), leaving a window where the callback
can retrieve a valid cctx pointer but operate on an uninitialized
spinlock. Second, the rpmsg channel becomes live as soon as the driver
is bound, so fastrpc_rpmsg_callback() can fire before dev_set_drvdata()
is called at all, resulting in dev_get_drvdata() returning NULL.
Fix both issues by moving all cctx initialization ahead of
dev_set_drvdata() so the structure is fully initialized before it
becomes visible to the callback, and add a NULL check in
fastrpc_rpmsg_callback() as a guard against any remaining window.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: fix DMA address corruption due to find_vma misuse
fastrpc_get_args() uses find_vma() to look up the VMA for a user-provided
pointer and compute a DMA address offset. When the address falls in a gap
before the returned VMA, (ptr & PAGE_MASK) - vma->vm_start underflows,
corrupting the DMA address sent to the DSP.
Replace find_vma() with vma_lookup(), which returns NULL when the address
is not contained within any VMA.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Validate XDomain request packet size before type cast
tb_xdp_handle_request() casts the received packet buffer to
protocol-specific structs without verifying that the allocation
is large enough for the target type. A peer can send a minimal
XDomain packet that passes the generic header length check but is
shorter than the struct accessed after the cast, causing out-of-
bounds reads from the kmemdup allocation.
Plumb the packet length through xdomain_request_work and validate
it against the expected struct size before each cast.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-06-25