Linux: >> Linux Kernel >> 6.6.142 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix memory leaks in beacon template setup
The functions ath11k_mac_setup_bcn_tmpl_ema() and
ath11k_mac_setup_bcn_tmpl_mbssid() allocate memory for beacon templates
but fail to free it when parameter setup returns an error.
Since beacon templates must be released during normal execution, they
must also be released in the error handling paths to prevent memory
leaks.
Fix this by using unified exit paths with proper cleanup in the respective
error paths.
Compile tested only. Issue found using a prototype static analysis tool
and code review.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bus: fsl-mc: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.
Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.
Note that calling match() from __driver_attach() without the device lock
held is intentional. [1]
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: Fix memory leak after mt76_connac_mcu_alloc_sta_req()
mt76_connac_mcu_alloc_sta_req() allocates an skb which is expected to
be freed eventually by mt76_mcu_skb_send_msg(). However, currently if
an intermediate function fails before sending, the allocated skb is
leaked.
Specifically, mt76_connac_mcu_sta_wed_update() and
mt76_connac_mcu_sta_key_tlv() may fail, leading to an immediate memory
leak in the error path.
Fix this by explicitly freeing the skb in these error paths.
Commit 7c0f63fe37a5 ("wifi: mt76: mt7996: fix memory leak on
mt7996_mcu_sta_key_tlv error") made a similar change.
Compile tested only. Issue found using a prototype static analysis tool
and code review.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf: Do not allow deleting local storage in NMI
Currently, local storage may deadlock when deferring freeing selem or
local storage through kfree_rcu(), call_rcu() or call_rcu_tasks_trace()
in NMI or reentrant. Since deleting selem in NMI is an unlikely use
case, partially mitigate it by returning error when calling from
bpf_xxx_storage_delete() helpers in NMI. Note that, it is still possible
to deadlock through reentrant. A full mitigation requires returning
error when irqs_disabled() is true, which, however is too heavy-handed
for bpf_xxx_storage_delete().
The long-term solution requires _nolock versions of call_rcu. Another
possible solution is to defer the free through irq_work [0], but it
would grow the size of selem, which is non-ideal.
The check is only needed in bpf_selem_unlink(), which is used by helpers
and syscalls. bpf_selem_unlink_nofail() is fine as it is called during
map and owner tear down that never run in NMI or reentrant.
[0] https://lore.kernel.org/bpf/20260205190233.912-1-alexei.starovoitov@gmail.com/
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: libertas: don't kill URBs in interrupt context
Serialization for the TX path was enforced by calling
usb_kill_urb()/usb_kill_anchored_urbs(), to prevent transmission before
a previous URB was completed. usb_tx_block() can be called from
interrupt context (e.g. in the HCD giveback path), so we can't always
use it to kill in-flight URBs.
Prevent sleeping during interrupt context by checking the tx_submitted
anchor for existing URBs. We now return -EBUSY, to indicate there's
a pending request.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix use-after-free in offloaded map/prog info fill
When querying info for an offloaded BPF map or program,
bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns()
obtain the network namespace with get_net(dev_net(offmap->netdev)).
However, the associated netdev's netns may be racing with teardown
during netns destruction. If the netns refcount has already reached 0,
get_net() performs a refcount_t increment on 0, triggering:
refcount_t: addition on 0; use-after-free.
Although rtnl_lock and bpf_devs_lock ensure the netdev pointer remains
valid, they cannot prevent the netns refcount from reaching zero.
Fix this by using maybe_get_net() instead of get_net(). maybe_get_net()
uses refcount_inc_not_zero() and returns NULL if the refcount is already
zero, which causes ns_get_path_cb() to fail and the caller to return
-ENOENT -- the correct behavior when the netns is being destroyed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix ld_{abs,ind} failure path analysis in subprogs
Usage of ld_{abs,ind} instructions got extended into subprogs some time
ago via commit 09b28d76eac4 ("bpf: Add abnormal return checks."). These
are only allowed in subprograms when the latter are BTF annotated and
have scalar return types.
The code generator in bpf_gen_ld_abs() has an abnormal exit path (r0=0 +
exit) from legacy cBPF times. While the enforcement is on scalar return
types, the verifier must also simulate the path of abnormal exit if the
packet data load via ld_{abs,ind} failed.
This is currently not the case. Fix it by having the verifier simulate
both success and failure paths, and extend it in similar ways as we do
for tail calls. The success path (r0=unknown, continue to next insn) is
pushed onto stack for later validation and the r0=0 and return to the
caller is done on the fall-through side.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
net: pull headers in qdisc_pkt_len_segs_init()
Most ndo_start_xmit() methods expects headers of gso packets
to be already in skb->head.
net/core/tso.c users are particularly at risk, because tso_build_hdr()
does a memcpy(hdr, skb->data, hdr_len);
qdisc_pkt_len_segs_init() already does a dissection of gso packets.
Use pskb_may_pull() instead of skb_header_pointer() to make
sure drivers do not have to reimplement this.
Some malicious packets could be fed, detect them so that we can
drop them sooner with a new SKB_DROP_REASON_SKB_BAD_GSO drop_reason.
CVSS Score
8.4
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: fix use-after-free bugs in mt7996_mac_dump_work()
When the mt7996 pci chip is detaching, the mt7996_crash_data is
released in mt7996_coredump_unregister(). However, the work item
dump_work may still be running or pending, leading to UAF bugs
when the already freed crash_data is dereferenced again in
mt7996_mac_dump_work().
The race condition can occur as follows:
CPU 0 (removal path) | CPU 1 (workqueue)
mt7996_pci_remove() | mt7996_sys_recovery_set()
mt7996_unregister_device() | mt7996_reset()
mt7996_coredump_unregister() | queue_work()
vfree(dev->coredump.crash_data) | mt7996_mac_dump_work()
| crash_data-> // UAF
Fix this by ensuring dump_work is properly canceled before
the crash_data is deallocated. Add cancel_work_sync() in
mt7996_unregister_device() to synchronize with any pending
or executing dump work.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_fw: fix NULL dereference of "old" filters before change()
Like pointed out by Sashiko [1], since commit ed76f5edccc9 ("net: sched:
protect filter_chain list with filter_chain_lock mutex") TC filters are
added to a shared block and published to datapath before their ->change()
function is called. This is a problem for cls_fw: an invalid filter
created with the "old" method can still classify some packets before it
is destroyed by the validation logic added by Xiang.
Therefore, insisting with repeated runs of the following script:
# ip link add dev crash0 type dummy
# ip link set dev crash0 up
# mausezahn crash0 -c 100000 -P 10 \
> -A 4.3.2.1 -B 1.2.3.4 -t udp "dp=1234" -q &
# sleep 1
# tc qdisc add dev crash0 egress_block 1 clsact
# tc filter add block 1 protocol ip prio 1 matchall \
> action skbedit mark 65536 continue
# tc filter add block 1 protocol ip prio 2 fw
# ip link del dev crash0
can still make fw_classify() hit the WARN_ON() in [2]:
WARNING: ./include/net/pkt_cls.h:88 at fw_classify+0x244/0x250 [cls_fw], CPU#18: mausezahn/1399
Modules linked in: cls_fw(E) act_skbedit(E)
CPU: 18 UID: 0 PID: 1399 Comm: mausezahn Tainted: G E 7.0.0-rc6-virtme #17 PREEMPT(full)
Tainted: [E]=UNSIGNED_MODULE
Hardware name: Red Hat KVM, BIOS 1.16.3-2.el9 04/01/2014
RIP: 0010:fw_classify+0x244/0x250 [cls_fw]
Code: 5c 49 c7 45 00 00 00 00 00 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 5b b8 ff ff ff ff 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 90 <0f> 0b 90 eb a0 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffd1b7026bf8a8 EFLAGS: 00010202
RAX: ffff8c5ac9c60800 RBX: ffff8c5ac99322c0 RCX: 0000000000000004
RDX: 0000000000000001 RSI: ffff8c5b74d7a000 RDI: ffff8c5ac8284f40
RBP: ffffd1b7026bf8d0 R08: 0000000000000000 R09: ffffd1b7026bf9b0
R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000010000
R13: ffffd1b7026bf930 R14: ffff8c5ac8284f40 R15: 0000000000000000
FS: 00007fca40c37740(0000) GS:ffff8c5b74d7a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fca40e822a0 CR3: 0000000005ca0001 CR4: 0000000000172ef0
Call Trace:
<TASK>
tcf_classify+0x17d/0x5c0
tc_run+0x9d/0x150
__dev_queue_xmit+0x2ab/0x14d0
ip_finish_output2+0x340/0x8f0
ip_output+0xa4/0x250
raw_sendmsg+0x147d/0x14b0
__sys_sendto+0x1cc/0x1f0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x126/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fca40e822ba
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
RSP: 002b:00007ffc248a42c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055ef233289d0 RCX: 00007fca40e822ba
RDX: 000000000000001e RSI: 000055ef23328c30 RDI: 0000000000000003
RBP: 000055ef233289d0 R08: 00007ffc248a42d0 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000001e
R13: 00000000000186a0 R14: 0000000000000000 R15: 00007fca41043000
</TASK>
irq event stamp: 1045778
hardirqs last enabled at (1045784): [<ffffffff864ec042>] __up_console_sem+0x52/0x60
hardirqs last disabled at (1045789): [<ffffffff864ec027>] __up_console_sem+0x37/0x60
softirqs last enabled at (1045426): [<ffffffff874d48c7>] __alloc_skb+0x207/0x260
softirqs last disabled at (1045434): [<ffffffff874fe8f8>] __dev_queue_xmit+0x78/0x14d0
Then, because of the value in the packet's mark, dereference on 'q->handle'
with NULL 'q' occurs:
BUG: kernel NULL pointer dereference, address: 0000000000000038
[...]
RIP: 0010:fw_classify+0x1fe/0x250 [cls_fw]
[...]
Skip "old-style" classification on shared blocks, so that the NULL
dereference is fixed and WARN_ON() is not hit anymore in the short
lifetime of invalid cls_fw "old-style" filters.
[1] https://sashiko.dev/#/patchset/2
---truncated---
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24