Linux: >> Linux Kernel >> 2.6.19.6 Security Vulnerabilities
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:
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:
USB: dwc3: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Note, the root dentry for the debugfs directory for the device needs to
be saved so we don't have to keep looking it up, which required a bit
more refactoring to properly create and remove it when needed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: isp1362: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: sl811: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: lpc32xx_udc: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18