In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_ct: bail out on template ct in get eval
I noticed this issue while looking at a historic syzbot report [1].
A rule like the one below is enough to trigger the bug:
table ip t {
chain pre {
type filter hook prerouting priority raw;
ct zone set 1
ct original saddr 1.2.3.4 accept
}
}
The first expression attaches a per-cpu template ct via
nft_ct_set_zone_eval() (nf_ct_tmpl_alloc -> kzalloc, tuple is all
zero, nf_ct_l3num(ct) == 0). The next expression then calls
nft_ct_get_eval() on the same skb, treats the template as a real ct
and hits the 16-byte memcpy path. With dreg at NFT_REG32_15 this
overflows past struct nft_regs on the kernel stack; with smaller
dreg values it silently clobbers adjacent registers.
Reject template ct at the eval entry and in nft_ct_get_fast_eval(),
mirroring the check nft_ct_set_eval() already has. Additionally,
bound the address copy in NFT_CT_SRC / NFT_CT_DST by priv->len
instead of by nf_ct_l3num(ct): nf_ct_get_tuple() zeroes the tuple
before pkt_to_tuple() fills in only the protocol-relevant leading
bytes, so the trailing bytes of tuple->{src,dst}.u3.all are
well-defined zero. priv->len is validated at rule load, so the
copy size is now bounded by the destination register rather than
by an untrusted field on the conntrack.
[1]: https://syzkaller.appspot.com/bug?id=389cf09cb72926114fce90dc85a2c3231dcb647c
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack_irc: fix possible out-of-bounds read
When parsing fails after we've matched the command string we
should bail out instead of trying to match a different command.
This helper should be deprecated, given prevalence of TLS I doubt it has
any relevance in 2026.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: Fix not releasing hdev reference on iso_conn_big_sync
hci_get_route() returns a reference-counted hci_dev pointer via
hci_dev_hold(). The function exits normally or with an error without ever
releasing it.
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.
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 (?:?)
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.
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].
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().
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: enforce HE/EHT cap/oper consistency
Xiang Mei reports that mac80211 could crash if eht_cap is set
but eht_oper isn't. Rather than fixing that for the individual
user(s), enforce that both HE/EHT have consistent elements.
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).