Linux: >> Linux Kernel >> 3.18.76 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sysfs: Fix attempting to call device_add multiple times
device_add shall not be called multiple times as stated in its
documentation:
'Do not call this routine or device_register() more than once for
any device structure'
Syzkaller reports a bug as follows [1]:
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:33!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
[...]
Call Trace:
<TASK>
__list_add include/linux/list.h:69 [inline]
list_add_tail include/linux/list.h:102 [inline]
kobj_kset_join lib/kobject.c:164 [inline]
kobject_add_internal+0x18f/0x8f0 lib/kobject.c:214
kobject_add_varg lib/kobject.c:358 [inline]
kobject_add+0x150/0x1c0 lib/kobject.c:410
device_add+0x368/0x1e90 drivers/base/core.c:3452
hci_conn_add_sysfs+0x9b/0x1b0 net/bluetooth/hci_sysfs.c:53
hci_le_cis_estabilished_evt+0x57c/0xae0 net/bluetooth/hci_event.c:6799
hci_le_meta_evt+0x2b8/0x510 net/bluetooth/hci_event.c:7110
hci_event_func net/bluetooth/hci_event.c:7440 [inline]
hci_event_packet+0x63d/0xfd0 net/bluetooth/hci_event.c:7495
hci_rx_work+0xae7/0x1230 net/bluetooth/hci_core.c:4007
process_one_work+0x991/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
For kernels built with CONFIG_PREEMPT_RCU=y, the following scenario can
result in a NULL-pointer dereference:
CPU1 CPU2
rcu_preempt_deferred_qs_irqrestore rcu_print_task_exp_stall
if (special.b.blocked) READ_ONCE(rnp->exp_tasks) != NULL
raw_spin_lock_rcu_node
np = rcu_next_node_entry(t, rnp)
if (&t->rcu_node_entry == rnp->exp_tasks)
WRITE_ONCE(rnp->exp_tasks, np)
....
raw_spin_unlock_irqrestore_rcu_node
raw_spin_lock_irqsave_rcu_node
t = list_entry(rnp->exp_tasks->prev,
struct task_struct, rcu_node_entry)
(if rnp->exp_tasks is NULL, this
will dereference a NULL pointer)
The problem is that CPU2 accesses the rcu_node structure's->exp_tasks
field without holding the rcu_node structure's ->lock and CPU2 did
not observe CPU1's change to rcu_node structure's ->exp_tasks in time.
Therefore, if CPU1 sets rcu_node structure's->exp_tasks pointer to NULL,
then CPU2 might dereference that NULL pointer.
This commit therefore holds the rcu_node structure's ->lock while
accessing that structure's->exp_tasks field.
[ paulmck: Apply Frederic Weisbecker feedback. ]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: fix use-after-free bug in brcmf_netdev_start_xmit()
> ret = brcmf_proto_tx_queue_data(drvr, ifp->ifidx, skb);
may be schedule, and then complete before the line
> ndev->stats.tx_bytes += skb->len;
[ 46.912801] ==================================================================
[ 46.920552] BUG: KASAN: use-after-free in brcmf_netdev_start_xmit+0x718/0x8c8 [brcmfmac]
[ 46.928673] Read of size 4 at addr ffffff803f5882e8 by task systemd-resolve/328
[ 46.935991]
[ 46.937514] CPU: 1 PID: 328 Comm: systemd-resolve Tainted: G O 5.4.199-[REDACTED] #1
[ 46.947255] Hardware name: [REDACTED]
[ 46.954568] Call trace:
[ 46.957037] dump_backtrace+0x0/0x2b8
[ 46.960719] show_stack+0x24/0x30
[ 46.964052] dump_stack+0x128/0x194
[ 46.967557] print_address_description.isra.0+0x64/0x380
[ 46.972877] __kasan_report+0x1d4/0x240
[ 46.976723] kasan_report+0xc/0x18
[ 46.980138] __asan_report_load4_noabort+0x18/0x20
[ 46.985027] brcmf_netdev_start_xmit+0x718/0x8c8 [brcmfmac]
[ 46.990613] dev_hard_start_xmit+0x1bc/0xda0
[ 46.994894] sch_direct_xmit+0x198/0xd08
[ 46.998827] __qdisc_run+0x37c/0x1dc0
[ 47.002500] __dev_queue_xmit+0x1528/0x21f8
[ 47.006692] dev_queue_xmit+0x24/0x30
[ 47.010366] neigh_resolve_output+0x37c/0x678
[ 47.014734] ip_finish_output2+0x598/0x2458
[ 47.018927] __ip_finish_output+0x300/0x730
[ 47.023118] ip_output+0x2e0/0x430
[ 47.026530] ip_local_out+0x90/0x140
[ 47.030117] igmpv3_sendpack+0x14c/0x228
[ 47.034049] igmpv3_send_cr+0x384/0x6b8
[ 47.037895] igmp_ifc_timer_expire+0x4c/0x118
[ 47.042262] call_timer_fn+0x1cc/0xbe8
[ 47.046021] __run_timers+0x4d8/0xb28
[ 47.049693] run_timer_softirq+0x24/0x40
[ 47.053626] __do_softirq+0x2c0/0x117c
[ 47.057387] irq_exit+0x2dc/0x388
[ 47.060715] __handle_domain_irq+0xb4/0x158
[ 47.064908] gic_handle_irq+0x58/0xb0
[ 47.068581] el0_irq_naked+0x50/0x5c
[ 47.072162]
[ 47.073665] Allocated by task 328:
[ 47.077083] save_stack+0x24/0xb0
[ 47.080410] __kasan_kmalloc.isra.0+0xc0/0xe0
[ 47.084776] kasan_slab_alloc+0x14/0x20
[ 47.088622] kmem_cache_alloc+0x15c/0x468
[ 47.092643] __alloc_skb+0xa4/0x498
[ 47.096142] igmpv3_newpack+0x158/0xd78
[ 47.099987] add_grhead+0x210/0x288
[ 47.103485] add_grec+0x6b0/0xb70
[ 47.106811] igmpv3_send_cr+0x2e0/0x6b8
[ 47.110657] igmp_ifc_timer_expire+0x4c/0x118
[ 47.115027] call_timer_fn+0x1cc/0xbe8
[ 47.118785] __run_timers+0x4d8/0xb28
[ 47.122457] run_timer_softirq+0x24/0x40
[ 47.126389] __do_softirq+0x2c0/0x117c
[ 47.130142]
[ 47.131643] Freed by task 180:
[ 47.134712] save_stack+0x24/0xb0
[ 47.138041] __kasan_slab_free+0x108/0x180
[ 47.142146] kasan_slab_free+0x10/0x18
[ 47.145904] slab_free_freelist_hook+0xa4/0x1b0
[ 47.150444] kmem_cache_free+0x8c/0x528
[ 47.154292] kfree_skbmem+0x94/0x108
[ 47.157880] consume_skb+0x10c/0x5a8
[ 47.161466] __dev_kfree_skb_any+0x88/0xa0
[ 47.165598] brcmu_pkt_buf_free_skb+0x44/0x68 [brcmutil]
[ 47.171023] brcmf_txfinalize+0xec/0x190 [brcmfmac]
[ 47.176016] brcmf_proto_bcdc_txcomplete+0x1c0/0x210 [brcmfmac]
[ 47.182056] brcmf_sdio_sendfromq+0x8dc/0x1e80 [brcmfmac]
[ 47.187568] brcmf_sdio_dpc+0xb48/0x2108 [brcmfmac]
[ 47.192529] brcmf_sdio_dataworker+0xc8/0x238 [brcmfmac]
[ 47.197859] process_one_work+0x7fc/0x1a80
[ 47.201965] worker_thread+0x31c/0xc40
[ 47.205726] kthread+0x2d8/0x370
[ 47.208967] ret_from_fork+0x10/0x18
[ 47.212546]
[ 47.214051] The buggy address belongs to the object at ffffff803f588280
[ 47.214051] which belongs to the cache skbuff_head_cache of size 208
[ 47.227086] The buggy address is located 104 bytes inside of
[ 47.227086] 208-byte region [ffffff803f588280, ffffff803f588350)
[ 47.238814] The buggy address belongs to the page:
[ 47.243618] page:ffffffff00dd6200 refcount:1 mapcou
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
net: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory
Fixes the below NULL pointer dereference:
[...]
[ 14.471200] Call Trace:
[ 14.471562] <TASK>
[ 14.471882] lock_acquire+0x245/0x2e0
[ 14.472416] ? remove_wait_queue+0x12/0x50
[ 14.473014] ? _raw_spin_lock_irqsave+0x17/0x50
[ 14.473681] _raw_spin_lock_irqsave+0x3d/0x50
[ 14.474318] ? remove_wait_queue+0x12/0x50
[ 14.474907] remove_wait_queue+0x12/0x50
[ 14.475480] sk_stream_wait_memory+0x20d/0x340
[ 14.476127] ? do_wait_intr_irq+0x80/0x80
[ 14.476704] do_tcp_sendpages+0x287/0x600
[ 14.477283] tcp_bpf_push+0xab/0x260
[ 14.477817] tcp_bpf_sendmsg_redir+0x297/0x500
[ 14.478461] ? __local_bh_enable_ip+0x77/0xe0
[ 14.479096] tcp_bpf_send_verdict+0x105/0x470
[ 14.479729] tcp_bpf_sendmsg+0x318/0x4f0
[ 14.480311] sock_sendmsg+0x2d/0x40
[ 14.480822] ____sys_sendmsg+0x1b4/0x1c0
[ 14.481390] ? copy_msghdr_from_user+0x62/0x80
[ 14.482048] ___sys_sendmsg+0x78/0xb0
[ 14.482580] ? vmf_insert_pfn_prot+0x91/0x150
[ 14.483215] ? __do_fault+0x2a/0x1a0
[ 14.483738] ? do_fault+0x15e/0x5d0
[ 14.484246] ? __handle_mm_fault+0x56b/0x1040
[ 14.484874] ? lock_is_held_type+0xdf/0x130
[ 14.485474] ? find_held_lock+0x2d/0x90
[ 14.486046] ? __sys_sendmsg+0x41/0x70
[ 14.486587] __sys_sendmsg+0x41/0x70
[ 14.487105] ? intel_pmu_drain_pebs_core+0x350/0x350
[ 14.487822] do_syscall_64+0x34/0x80
[ 14.488345] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]
The test scenario has the following flow:
thread1 thread2
----------- ---------------
tcp_bpf_sendmsg
tcp_bpf_send_verdict
tcp_bpf_sendmsg_redir sock_close
tcp_bpf_push_locked __sock_release
tcp_bpf_push //inet_release
do_tcp_sendpages sock->ops->release
sk_stream_wait_memory // tcp_close
sk_wait_event sk->sk_prot->close
release_sock(__sk);
***
lock_sock(sk);
__tcp_close
sock_orphan(sk)
sk->sk_wq = NULL
release_sock
****
lock_sock(__sk);
remove_wait_queue(sk_sleep(sk), &wait);
sk_sleep(sk)
//NULL pointer dereference
&rcu_dereference_raw(sk->sk_wq)->wait
While waiting for memory in thread1, the socket is released with its wait
queue because thread2 has closed it. This caused by tcp_bpf_send_verdict
didn't increase the f_count of psock->sk_redir->sk_socket->file in thread1.
We should check if SOCK_DEAD flag is set on wakeup in sk_stream_wait_memory
before accessing the wait queue.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Protect against send buffer overflow in NFSv2 READ
Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply at the same time.
Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.
A client can force this shrinkage on TCP by sending a correctly-
formed RPC Call header contained in an RPC record that is
excessively large. The full maximum payload size cannot be
constructed in that case.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
ACPICA: Fix error code path in acpi_ds_call_control_method()
A use-after-free in acpi_ps_parse_aml() after a failing invocaion of
acpi_ds_call_control_method() is reported by KASAN [1] and code
inspection reveals that next_walk_state pushed to the thread by
acpi_ds_create_walk_state() is freed on errors, but it is not popped
from the thread beforehand. Thus acpi_ds_get_current_walk_state()
called by acpi_ps_parse_aml() subsequently returns it as the new
walk state which is incorrect.
To address this, make acpi_ds_call_control_method() call
acpi_ds_pop_walk_state() to pop next_walk_state from the thread before
returning an error.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
scsi: fcoe: Fix transport not deattached when fcoe_if_init() fails
fcoe_init() calls fcoe_transport_attach(&fcoe_sw_transport), but when
fcoe_if_init() fails, &fcoe_sw_transport is not detached and leaves freed
&fcoe_sw_transport on fcoe_transports list. This causes panic when
reinserting module.
BUG: unable to handle page fault for address: fffffbfff82e2213
RIP: 0010:fcoe_transport_attach+0xe1/0x230 [libfcoe]
Call Trace:
<TASK>
do_one_initcall+0xd0/0x4e0
load_module+0x5eee/0x7210
...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
parisc: led: Fix potential null-ptr-deref in start_task()
start_task() calls create_singlethread_workqueue() and not checked the
ret value, which may return NULL. And a null-ptr-deref may happen:
start_task()
create_singlethread_workqueue() # failed, led_wq is NULL
queue_delayed_work()
queue_delayed_work_on()
__queue_delayed_work() # warning here, but continue
__queue_work() # access wq->flags, null-ptr-deref
Check the ret value and return -ENOMEM if it is NULL.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
drivers/md/md-bitmap: check the return value of md_bitmap_get_counter()
Check the return value of md_bitmap_get_counter() in case it returns
NULL pointer, which will result in a null pointer dereference.
v2: update the check to include other dereference
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
net/tunnel: wait until all sk_user_data reader finish before releasing the sock
There is a race condition in vxlan that when deleting a vxlan device
during receiving packets, there is a possibility that the sock is
released after getting vxlan_sock vs from sk_user_data. Then in
later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got
NULL pointer dereference. e.g.
#0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757
#1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d
#2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48
#3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b
#4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb
#5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542
#6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62
[exception RIP: vxlan_ecn_decapsulate+0x3b]
RIP: ffffffffc1014e7b RSP: ffffa25ec6978cb0 RFLAGS: 00010246
RAX: 0000000000000008 RBX: ffff8aa000888000 RCX: 0000000000000000
RDX: 000000000000000e RSI: ffff8a9fc7ab803e RDI: ffff8a9fd1168700
RBP: ffff8a9fc7ab803e R8: 0000000000700000 R9: 00000000000010ae
R10: ffff8a9fcb748980 R11: 0000000000000000 R12: ffff8a9fd1168700
R13: ffff8aa000888000 R14: 00000000002a0000 R15: 00000000000010ae
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan]
#8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507
#9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45
#10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807
#11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951
#12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde
#13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b
#14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139
#15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a
#16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3
#17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca
#18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3
Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh
Fix this by waiting for all sk_user_data reader to finish before
releasing the sock.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18