Linux: >> Linux Kernel >> 6.11.8 Security Vulnerabilities
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:
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
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown
mtk_free_dev() calls metadata_dst_free() which frees the metadata_dst
with kfree() immediately, bypassing the RCU grace period.
In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from
the skb to the metadata_dst. This function requires RCU read-side
protection and the dst must remain valid until all RCU readers complete.
Since metadata_dst_free() calls kfree() directly, a use-after-free can
occur if any skb still holds a noref pointer to the dst when the driver
tears it down.
Replace metadata_dst_free() with dst_release() which properly goes
through the refcount path: when the refcount drops to zero, it schedules
the actual free via call_rcu_hurry(), ensuring all RCU readers have
completed before the memory is freed.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options
This patch restricts setting Loose Source and Record Route (LSRR)
and Strict Source and Record Route (SSRR) IP options to users
with CAP_NET_RAW capability.
This prevents unprivileged applications from forcing packets to route
through attacker-controlled nodes to leak TCP ISN and possibly other
protocol information.
While LSRR and SSRR are commonly filtered in many network environments,
they may still be supported and forwarded along some network paths.
RFC 7126 (Recommendations on Filtering of IPv4 Packets Containing
IPv4 Options) recommend to drop these options in 4.3 and 4.4.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()
The TX metadata area resides in the UMEM buffer which is memory-mapped
and concurrently writable by userspace. In xsk_skb_metadata(),
csum_start and csum_offset are read from shared memory for bounds
validation, then read again for skb assignment. A malicious userspace
application can race to overwrite these values between the two reads,
bypassing the bounds check and causing out-of-bounds memory access
during checksum computation in the transmit path.
Fix this by reading csum_start and csum_offset into local variables
once, then using the local copies for both validation and assignment.
Note that other metadata fields (flags, launch_time) and the cached
csum fields may be mutually inconsistent due to concurrent userspace
writes, but this is benign: the only security-critical invariant is
that each field's validated value is the same one used, which local
caching guarantees.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
net: phy: clean the sfp upstream if phy probing fails
Sashiko reported that we don't call sfp_bus_del_upstream() in the probe
failure path, so let's add it, otherwise the sfp-bus is left with a
dangling 'upstream' field, that may be used later on during SFP events.
This issue existed before the generic phylib sfp support, back when
drivers were calling phy_sfp_probe themselves.
CVSS Score
8.8
EPSS Score
0.002
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
net: add pskb_may_pull() to skb_gro_receive_list()
skb_gro_receive_list() calls skb_pull(skb, skb_gro_offset(skb)) without
first ensuring the data is in the linear area via pskb_may_pull(). When
the skb arrives via napi_gro_frags(), skb_headlen can be 0 (all data in
page fragments) while skb_gro_offset is non-zero (after IP+TCP header
parsing). The skb_pull() then decrements skb->len by skb_gro_offset
but skb->data_len stays unchanged, hitting BUG_ON(skb->len < skb->data_len)
in __skb_pull().
The UDP fraglist GRO path already contains this guard at
udp_offload.c:749. Adding it to skb_gro_receive_list() itself provides
centralized protection for all callers (TCP, UDP, and any future
protocols), and ensures the precondition of skb_pull() is satisfied
before it is called.
On pskb_may_pull() failure, set NAPI_GRO_CB(skb)->flush = 1 so the
skb is not held as a new GRO head and is instead delivered through the
normal receive path, matching the UDP handling.
CVSS Score
7.5
EPSS Score
0.005
Published
2026-06-25