Linux: >> Linux Kernel >> 6.12.37 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: fix memory leak in error path of hci_alloc_dev()
Early failures in Bluetooth HCI UART configuration leak SRCU percpu
memory.
When device initialization fails before hci_register_dev() completes,
the HCI_UNREGISTER flag is never set. As a result, when the device
reference count reaches zero, bt_host_release() evaluates this flag as
false and falls back to a direct kfree(hdev).
Because hci_release_dev() is bypassed, the SRCU struct initialized
early in hci_alloc_dev() is never cleaned up, resulting in a leak of
percpu memory.
Fix the leak by explicitly calling cleanup_srcu_struct() in the
fallback (unregistered) branch of bt_host_release() before freeing
the device.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: bnep: reject short frames before parsing
A BNEP peer can send a short BNEP SDU. bnep_rx_frame() reads the
packet type byte immediately and, for control packets, reads the control
opcode and setup UUID-size byte before proving that those bytes are
present. bnep_rx_control() also dereferences the control opcode without
rejecting an empty control payload.
Use skb_pull_data() for the fixed fields in bnep_rx_frame() so a NULL
return gates each dereference. Split the control handler so the frame
path can pass an opcode that has already been pulled, and keep the
byte-buffer wrapper for extension control payloads.
For BNEP_SETUP_CONN_REQ, name the UUID-size byte before pulling the
setup payload. struct bnep_setup_conn_req carries destination and source
service UUIDs after that byte, each uuid_size bytes, so the parser now
documents that tuple explicitly instead of leaving the pull length as an
opaque multiplication.
Validation reproduced this kernel report:
KASAN slab-out-of-bounds in bnep_rx_frame.isra.0+0x130c/0x1790
The buggy address belongs to the object at ffff88800c0f7908 which belongs
to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of allocated 1-byte
region [ffff88800c0f7908, ffff88800c0f7909)
Read of size 1
Call trace:
dump_stack_lvl+0xb3/0x140 (?:?)
print_address_description+0x57/0x3a0 (?:?)
bnep_rx_frame+0x130c/0x1790 (net/bluetooth/bnep/core.c:306)
print_report+0xb9/0x2b0 (?:?)
__virt_addr_valid+0x1ba/0x3a0 (?:?)
srso_alias_return_thunk+0x5/0xfbef5 (?:?)
kasan_addr_to_slab+0x21/0x60 (?:?)
kasan_report+0xe0/0x110 (?:?)
process_one_work+0xfce/0x17e0 (kernel/workqueue.c:3200)
worker_thread+0x65c/0xe40 (?:?)
__kthread_parkme+0x184/0x230 (?:?)
kthread+0x35e/0x470 (?:?)
_raw_spin_unlock_irq+0x28/0x50 (?:?)
ret_from_fork+0x586/0x870 (?:?)
__switch_to+0x74f/0xdc0 (?:?)
ret_from_fork_asm+0x1a/0x30 (?:?)
CVSS Score
7.1
EPSS Score
0.003
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: validate skb length in MCC handlers
The RFCOMM MCC handlers cast skb->data to protocol-specific structs
without validating skb->len first. A malicious remote device can send
truncated MCC frames and trigger out-of-bounds reads in these handlers.
Fix this by using skb_pull_data() to validate and access the required
data before dereferencing it.
rfcomm_recv_rpn() requires special handling since ETSI TS 07.10 allows
1-byte RPN requests. Handle this by validating only the DLCI byte first,
and validating the full struct only when len > 1.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: MGMT: validate advertising TLV before type checks
tlv_data_is_valid() reads each advertising data field length from
data[i], then inspects data[i + 1] for managed EIR types before
checking that the current field still fits inside the supplied buffer.
A malformed field whose length byte is the last byte of the buffer can
therefore make the parser read one byte past the advertising data.
KASAN reported the following when a malformed MGMT_OP_ADD_ADVERTISING
request reached that path:
BUG: KASAN: vmalloc-out-of-bounds in tlv_data_is_valid()
Read of size 1
Call trace:
tlv_data_is_valid()
add_advertising()
hci_mgmt_cmd()
hci_sock_sendmsg()
Move the existing element-length check before any type-octet inspection
so each non-empty element is proven to contain its type byte before the
parser looks at data[i + 1].
CVSS Score
7.1
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()
rfcomm_get_sock_by_channel() scans rfcomm_sk_list under the list lock,
but returns the selected listener after dropping that lock without
taking a reference. rfcomm_connect_ind() then locks the listener,
queues a child socket on it, and may notify it after unlocking it.
The buggy scenario involves two paths, with each column showing the
order within that path:
rfcomm_connect_ind(): listener close:
1. Find parent in 1. close() enters
rfcomm_get_sock_by_channel() rfcomm_sock_release().
2. Drop rfcomm_sk_list.lock 2. rfcomm_sock_shutdown()
without pinning parent. closes the listener.
3. Call lock_sock(parent) and 3. rfcomm_sock_kill()
bt_accept_enqueue(parent, unlinks and puts parent.
sk, true).
4. Read parent flags and may 4. parent can be freed.
call sk_state_change().
If close wins the race, parent can be freed before
rfcomm_connect_ind() reaches lock_sock(), bt_accept_enqueue(), or the
deferred-setup callback.
Take a reference on the listener before leaving rfcomm_sk_list.lock.
After lock_sock() succeeds, recheck that it is still in BT_LISTEN
before queueing a child, cache the deferred-setup bit while the parent
is locked, and drop the reference after the last parent use.
KASAN reported a slab-use-after-free in lock_sock_nested() from
rfcomm_connect_ind(), with the freeing stack going through
rfcomm_sock_kill() and rfcomm_sock_release().
CVSS Score
8.0
EPSS Score
0.003
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
wifi: fix leak if split 6 GHz scanning fails
rdev->int_scan_req is leaked if cfg80211_scan() fails. Note that it's
supposed to be released at ___cfg80211_scan_done() but this doesn't happen
as rdev->scan_req is NULL at that point, too, leading to the early return
from the freeing function.
unreferenced object 0xffff8881161d0800 (size 512):
comm "wpa_supplicant", pid 379, jiffies 4294749765
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 f0 81 13 16 81 88 ff ff ................
backtrace (crc c867fdb6):
kmemleak_alloc+0x89/0x90
__kmalloc_noprof+0x2fd/0x410
cfg80211_scan+0x133/0x730
nl80211_trigger_scan+0xc69/0x1cc0
genl_family_rcv_msg_doit+0x204/0x2f0
genl_rcv_msg+0x431/0x6b0
netlink_rcv_skb+0x143/0x3f0
genl_rcv+0x27/0x40
netlink_unicast+0x4f6/0x820
netlink_sendmsg+0x797/0xce0
__sock_sendmsg+0xc4/0x160
____sys_sendmsg+0x5e4/0x890
___sys_sendmsg+0xf8/0x180
__sys_sendmsg+0x136/0x1e0
__x64_sys_sendmsg+0x76/0xc0
x64_sys_call+0x13f0/0x17d0
Found by Linux Verification Center (linuxtesting.org).
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().
The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.
Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.
This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.
Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the reqsk due to its listener's close().
Let's wrap mod_timer() and refcount_set() with
preempt_disable_nested() and preempt_enable_nested().
Note that inet_ehash_insert() holds the normal spin_lock()
(mutex in PREEMPT_RT), so it must be called outside of
preempt_disable_nested(), but this is fine.
The lookup path just ignores 0 sk_refcnt entries in ehash
and tries to create another reqsk, but this will fail at
inet_ehash_insert().
[0]:
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28, CPU#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: e4 7d d1 0a 67 48 0f b9 3a eb 4a e8 38 3d 23 fd 48 8d 3d e1 7d d1 0a 67 48 0f b9 3a eb 37 e8 25 3d 23 fd 48 8d 3d de 7d d1 0a <67> 48 0f b9 3a eb 24 e8 12 3d 23 fd 48 8d 3d db 7d d1 0a 67 48 0f
RSP: 0000:ffffc90000157948 EFLAGS: 00010246
RAX: ffffffff84a1301b RBX: 0000000000000003 RCX: ffff88801ca98000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8f72ae00
RBP: ffffffff99ae3b01 R08: ffff88801ca98000 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880425ef568
R13: ffff8880425ef4f8 R14: ffff8880425ef578 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126386000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b46710e9c CR3: 000000000dbb6000 CR4: 00000000003526f0
Call Trace:
<TASK>
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
reqsk_put include/net/request_sock.h:136 [inline]
__inet_csk_reqsk_queue_drop+0x3ce/0x440 net/ipv4/inet_connection_sock.c:1007
reqsk_timer_handler+0x651/0xdf0 net/ipv4/inet_connection_sock.c:1137
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0x67/0x170 kernel/time/timer.c:2403
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1151
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
CVSS Score
9.8
EPSS Score
0.003
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: dummy: fix UMP event stack overread
The dummy sequencer port forwards events by copying an incoming
struct snd_seq_event into a stack temporary, rewriting source and
destination, and dispatching the temporary to subscribers. That legacy
event storage is smaller than struct snd_seq_ump_event.
When a UMP event reaches the dummy client, the copy leaves the UMP flag
set but only provides legacy-sized stack storage. The subscriber
delivery path then uses snd_seq_event_packet_size() and copies a
UMP-sized packet from that stack object, reading past the end of the
temporary.
Use the existing union __snd_seq_event storage and copy the packet size
reported for the incoming event before rewriting the common routing
fields. This preserves the full UMP packet for UMP events while keeping
legacy event handling unchanged.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
net/802/mrp: fix vector attribute parsing in mrp_pdu_parse_vecattr
In mrp_pdu_parse_vecattr(), vector attribute events are encoded three
per byte and valen tracks the number of events left to process.
The parser decrements valen after processing the first and second events
from each event byte, but not after processing the third one. When valen
is exactly a multiple of three, the loop continues after the last valid
event and consumes the next byte as a new event byte, applying a
spurious event to the MRP applicant state.
Additionally, when valen is zero the parser unconditionally consumes
attrlen bytes as FirstValue and advances the offset, even though per
IEEE 802.1ak a VectorAttribute with only a LeaveAllEvent has valen of
zero and no FirstValue or Vector fields. This corrupts the offset for
subsequent PDU parsing.
Also, when valen exceeds three the loop crosses byte boundaries but
the attribute value is not incremented between the last event of one
byte and the first event of the next. This causes the first event of
the next byte to use the same attribute value as the third event
rather than the next consecutive value.
Decrement valen after processing the third event, skip FirstValue
consumption when valen is zero, and increment the attribute value at
the end of each loop iteration.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing
When a listening SCTP server processes a COOKIE_ECHO chunk, the cached
peer INIT chunk embedded after the cookie is parsed and its parameters
are later walked by sctp_process_init() using sctp_walk_params().
However, the chunk header length of this cached INIT chunk was not
validated against the remaining buffer in the COOKIE_ECHO payload. If
the length field is inflated, the parameter walk can run beyond the
actual received data, leading to out-of-bounds reads and potential
memory corruption during later parameter handling (e.g. STATE_COOKIE
processing and kmemdup() copies).
Add a bounds check in sctp_unpack_cookie() to ensure the cached INIT
chunk length does not exceed the available data in the COOKIE_ECHO
buffer before it is used.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-06-25