Security Vulnerabilities - CVEs Published In October 2025
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Check instead of asserting on nested TSC scaling support
Check for nested TSC scaling support on nested SVM VMRUN instead of
asserting that TSC scaling is exposed to L1 if L1's MSR_AMD64_TSC_RATIO
has diverged from KVM's default. Userspace can trigger the WARN at will
by writing the MSR and then updating guest CPUID to hide the feature
(modifying guest CPUID is allowed anytime before KVM_RUN). E.g. hacking
KVM's state_test selftest to do
vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0);
vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR);
after restoring state in a new VM+vCPU yields an endless supply of:
------------[ cut here ]------------
WARNING: CPU: 164 PID: 62565 at arch/x86/kvm/svm/nested.c:699
nested_vmcb02_prepare_control+0x3d6/0x3f0 [kvm_amd]
Call Trace:
<TASK>
enter_svm_guest_mode+0x114/0x560 [kvm_amd]
nested_svm_vmrun+0x260/0x330 [kvm_amd]
vmrun_interception+0x29/0x30 [kvm_amd]
svm_invoke_exit_handler+0x35/0x100 [kvm_amd]
svm_handle_exit+0xe7/0x180 [kvm_amd]
kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm]
kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm]
__se_sys_ioctl+0x7a/0xc0
__x64_sys_ioctl+0x21/0x30
do_syscall_64+0x41/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x45ca1b
Note, the nested #VMEXIT path has the same flaw, but needs a different
fix and will be handled separately.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
OPP: Fix potential null ptr dereference in dev_pm_opp_get_required_pstate()
"opp" pointer is dereferenced before the IS_ERR_OR_NULL() check. Fix it by
removing the dereference to cache opp_table and dereference it directly
where opp_table is used.
This fixes the following smatch warning:
drivers/opp/core.c:232 dev_pm_opp_get_required_pstate() warn: variable
dereferenced before IS_ERR check 'opp' (see line 230)
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
md: don't dereference mddev after export_rdev()
Except for initial reference, mddev->kobject is referenced by
rdev->kobject, and if the last rdev is freed, there is no guarantee that
mddev is still valid. Hence mddev should not be used anymore after
export_rdev().
This problem can be triggered by following test for mdadm at very
low rate:
New file: mdadm/tests/23rdev-lifetime
devname=${dev0##*/}
devt=`cat /sys/block/$devname/dev`
pid=""
runtime=2
clean_up_test() {
pill -9 $pid
echo clear > /sys/block/md0/md/array_state
}
trap 'clean_up_test' EXIT
add_by_sysfs() {
while true; do
echo $devt > /sys/block/md0/md/new_dev
done
}
remove_by_sysfs(){
while true; do
echo remove > /sys/block/md0/md/dev-${devname}/state
done
}
echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed"
add_by_sysfs &
pid="$pid $!"
remove_by_sysfs &
pid="$pid $!"
sleep $runtime
exit 0
Test cmd:
./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime
Test result:
general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP
CPU: 0 PID: 1292 Comm: test Tainted: G D W 6.5.0-rc2-00121-g01e55c376936 #562
RIP: 0010:md_wakeup_thread+0x9e/0x320 [md_mod]
Call Trace:
<TASK>
mddev_unlock+0x1b6/0x310 [md_mod]
rdev_attr_store+0xec/0x190 [md_mod]
sysfs_kf_write+0x52/0x70
kernfs_fop_write_iter+0x19a/0x2a0
vfs_write+0x3b5/0x770
ksys_write+0x74/0x150
__x64_sys_write+0x22/0x30
do_syscall_64+0x40/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fix this problem by don't dereference mddev after export_rdev().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: wcd938x: fix missing mbhc init error handling
MBHC initialisation can fail so add the missing error handling to avoid
dereferencing an error pointer when later configuring the jack:
Unable to handle kernel paging request at virtual address fffffffffffffff8
pc : wcd_mbhc_start+0x28/0x380 [snd_soc_wcd_mbhc]
lr : wcd938x_codec_set_jack+0x28/0x48 [snd_soc_wcd938x]
Call trace:
wcd_mbhc_start+0x28/0x380 [snd_soc_wcd_mbhc]
wcd938x_codec_set_jack+0x28/0x48 [snd_soc_wcd938x]
snd_soc_component_set_jack+0x28/0x8c [snd_soc_core]
qcom_snd_wcd_jack_setup+0x7c/0x19c [snd_soc_qcom_common]
sc8280xp_snd_init+0x20/0x2c [snd_soc_sc8280xp]
snd_soc_link_init+0x28/0x90 [snd_soc_core]
snd_soc_bind_card+0x628/0xbfc [snd_soc_core]
snd_soc_register_card+0xec/0x104 [snd_soc_core]
devm_snd_soc_register_card+0x4c/0xa4 [snd_soc_core]
sc8280xp_platform_probe+0xf0/0x108 [snd_soc_sc8280xp]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
net: cdc_ncm: Deal with too low values of dwNtbOutMaxSize
Currently in cdc_ncm_check_tx_max(), if dwNtbOutMaxSize is lower than
the calculated "min" value, but greater than zero, the logic sets
tx_max to dwNtbOutMaxSize. This is then used to allocate a new SKB in
cdc_ncm_fill_tx_frame() where all the data is handled.
For small values of dwNtbOutMaxSize the memory allocated during
alloc_skb(dwNtbOutMaxSize, GFP_ATOMIC) will have the same size, due to
how size is aligned at alloc time:
size = SKB_DATA_ALIGN(size);
size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
Thus we hit the same bug that we tried to squash with
commit 2be6d4d16a084 ("net: cdc_ncm: Allow for dwNtbOutMaxSize to be unset or zero")
Low values of dwNtbOutMaxSize do not cause an issue presently because at
alloc_skb() time more memory (512b) is allocated than required for the
SKB headers alone (320b), leaving some space (512b - 320b = 192b)
for CDC data (172b).
However, if more elements (for example 3 x u64 = [24b]) were added to
one of the SKB header structs, say 'struct skb_shared_info',
increasing its original size (320b [320b aligned]) to something larger
(344b [384b aligned]), then suddenly the CDC data (172b) no longer
fits in the spare SKB data area (512b - 384b = 128b).
Consequently the SKB bounds checking semantics fails and panics:
skbuff: skb_over_panic: text:ffffffff831f755b len:184 put:172 head:ffff88811f1c6c00 data:ffff88811f1c6c00 tail:0xb8 end:0x80 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:113!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 57 Comm: kworker/0:2 Not tainted 5.15.106-syzkaller-00249-g19c0ed55a470 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Workqueue: mld mld_ifc_work
RIP: 0010:skb_panic net/core/skbuff.c:113 [inline]
RIP: 0010:skb_over_panic+0x14c/0x150 net/core/skbuff.c:118
[snip]
Call Trace:
<TASK>
skb_put+0x151/0x210 net/core/skbuff.c:2047
skb_put_zero include/linux/skbuff.h:2422 [inline]
cdc_ncm_ndp16 drivers/net/usb/cdc_ncm.c:1131 [inline]
cdc_ncm_fill_tx_frame+0x11ab/0x3da0 drivers/net/usb/cdc_ncm.c:1308
cdc_ncm_tx_fixup+0xa3/0x100
Deal with too low values of dwNtbOutMaxSize, clamp it in the range
[USB_CDC_NCM_NTB_MIN_OUT_SIZE, CDC_NCM_NTB_MAX_SIZE_TX]. We ensure
enough data space is allocated to handle CDC data by making sure
dwNtbOutMaxSize is not smaller than USB_CDC_NCM_NTB_MIN_OUT_SIZE.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Fix deadloop issue on reading trace_pipe
Soft lockup occurs when reading file 'trace_pipe':
watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [cat:4488]
[...]
RIP: 0010:ring_buffer_empty_cpu+0xed/0x170
RSP: 0018:ffff88810dd6fc48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff93d1aaeb
RDX: ffff88810a280040 RSI: 0000000000000008 RDI: ffff88811164b218
RBP: ffff88811164b218 R08: 0000000000000000 R09: ffff88815156600f
R10: ffffed102a2acc01 R11: 0000000000000001 R12: 0000000051651901
R13: 0000000000000000 R14: ffff888115e49500 R15: 0000000000000000
[...]
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d853c2000 CR3: 000000010dcd8000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__find_next_entry+0x1a8/0x4b0
? peek_next_entry+0x250/0x250
? down_write+0xa5/0x120
? down_write_killable+0x130/0x130
trace_find_next_entry_inc+0x3b/0x1d0
tracing_read_pipe+0x423/0xae0
? tracing_splice_read_pipe+0xcb0/0xcb0
vfs_read+0x16b/0x490
ksys_read+0x105/0x210
? __ia32_sys_pwrite64+0x200/0x200
? switch_fpu_return+0x108/0x220
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x61/0xc6
Through the vmcore, I found it's because in tracing_read_pipe(),
ring_buffer_empty_cpu() found some buffer is not empty but then it
cannot read anything due to "rb_num_of_entries() == 0" always true,
Then it infinitely loop the procedure due to user buffer not been
filled, see following code path:
tracing_read_pipe() {
... ...
waitagain:
tracing_wait_pipe() // 1. find non-empty buffer here
trace_find_next_entry_inc() // 2. loop here try to find an entry
__find_next_entry()
ring_buffer_empty_cpu(); // 3. find non-empty buffer
peek_next_entry() // 4. but peek always return NULL
ring_buffer_peek()
rb_buffer_peek()
rb_get_reader_page()
// 5. because rb_num_of_entries() == 0 always true here
// then return NULL
// 6. user buffer not been filled so goto 'waitgain'
// and eventually leads to an deadloop in kernel!!!
}
By some analyzing, I found that when resetting ringbuffer, the 'entries'
of its pages are not all cleared (see rb_reset_cpu()). Then when reducing
the ringbuffer, and if some reduced pages exist dirty 'entries' data, they
will be added into 'cpu_buffer->overrun' (see rb_remove_pages()), which
cause wrong 'overrun' count and eventually cause the deadloop issue.
To fix it, we need to clear every pages in rb_reset_cpu().
CVSS Score
7.1
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix skb_copy_ubufs() vs BIG TCP
David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy
using hugepages, and skb length bigger than ~68 KB.
skb_copy_ubufs() assumed it could copy all payload using up to
MAX_SKB_FRAGS order-0 pages.
This assumption broke when BIG TCP was able to put up to 512 KB per skb.
We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45
and limit gso_max_size to 180000.
A solution is to use higher order pages if needed.
v2: add missing __GFP_COMP, or we leak memory.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
nvme-core: fix dev_pm_qos memleak
Call dev_pm_qos_hide_latency_tolerance() in the error unwind patch to
avoid following kmemleak:-
blktests (master) # kmemleak-clear; ./check nvme/044;
blktests (master) # kmemleak-scan ; kmemleak-show
nvme/044 (Test bi-directional authentication) [passed]
runtime 2.111s ... 2.124s
unreferenced object 0xffff888110c46240 (size 96):
comm "nvme", pid 33461, jiffies 4345365353 (age 75.586s)
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 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000069ac2cec>] kmalloc_trace+0x25/0x90
[<000000006acc66d5>] dev_pm_qos_update_user_latency_tolerance+0x6f/0x100
[<00000000cc376ea7>] nvme_init_ctrl+0x38e/0x410 [nvme_core]
[<000000007df61b4b>] 0xffffffffc05e88b3
[<00000000d152b985>] 0xffffffffc05744cb
[<00000000f04a4041>] vfs_write+0xc5/0x3c0
[<00000000f9491baf>] ksys_write+0x5f/0xe0
[<000000001c46513d>] do_syscall_64+0x3b/0x90
[<00000000ecf348fe>] entry_SYSCALL_64_after_hwframe+0x72/0xdc
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
Registering a kprobe on __rcu_irq_enter_check_tick() can cause kernel
stack overflow as shown below. This issue can be reproduced by enabling
CONFIG_NO_HZ_FULL and booting the kernel with argument "nohz_full=",
and then giving the following commands at the shell prompt:
# cd /sys/kernel/tracing/
# echo 'p:mp1 __rcu_irq_enter_check_tick' >> kprobe_events
# echo 1 > events/kprobes/enable
This commit therefore adds __rcu_irq_enter_check_tick() to the kprobes
blacklist using NOKPROBE_SYMBOL().
Insufficient stack space to handle exception!
ESR: 0x00000000f2000004 -- BRK (AArch64)
FAR: 0x0000ffffccf3e510
Task stack: [0xffff80000ad30000..0xffff80000ad38000]
IRQ stack: [0xffff800008050000..0xffff800008058000]
Overflow stack: [0xffff089c36f9f310..0xffff089c36fa0310]
CPU: 5 PID: 190 Comm: bash Not tainted 6.2.0-rc2-00320-g1f5abbd77e2c #19
Hardware name: linux,dummy-virt (DT)
pstate: 400003c5 (nZcv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __rcu_irq_enter_check_tick+0x0/0x1b8
lr : ct_nmi_enter+0x11c/0x138
sp : ffff80000ad30080
x29: ffff80000ad30080 x28: ffff089c82e20000 x27: 0000000000000000
x26: 0000000000000000 x25: ffff089c02a8d100 x24: 0000000000000000
x23: 00000000400003c5 x22: 0000ffffccf3e510 x21: ffff089c36fae148
x20: ffff80000ad30120 x19: ffffa8da8fcce148 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: ffffa8da8e44ea6c
x14: ffffa8da8e44e968 x13: ffffa8da8e03136c x12: 1fffe113804d6809
x11: ffff6113804d6809 x10: 0000000000000a60 x9 : dfff800000000000
x8 : ffff089c026b404f x7 : 00009eec7fb297f7 x6 : 0000000000000001
x5 : ffff80000ad30120 x4 : dfff800000000000 x3 : ffffa8da8e3016f4
x2 : 0000000000000003 x1 : 0000000000000000 x0 : 0000000000000000
Kernel panic - not syncing: kernel stack overflow
CPU: 5 PID: 190 Comm: bash Not tainted 6.2.0-rc2-00320-g1f5abbd77e2c #19
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0xf8/0x108
show_stack+0x20/0x30
dump_stack_lvl+0x68/0x84
dump_stack+0x1c/0x38
panic+0x214/0x404
add_taint+0x0/0xf8
panic_bad_stack+0x144/0x160
handle_bad_stack+0x38/0x58
__bad_stack+0x78/0x7c
__rcu_irq_enter_check_tick+0x0/0x1b8
arm64_enter_el1_dbg.isra.0+0x14/0x20
el1_dbg+0x2c/0x90
el1h_64_sync_handler+0xcc/0xe8
el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8
arm64_enter_el1_dbg.isra.0+0x14/0x20
el1_dbg+0x2c/0x90
el1h_64_sync_handler+0xcc/0xe8
el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8
arm64_enter_el1_dbg.isra.0+0x14/0x20
el1_dbg+0x2c/0x90
el1h_64_sync_handler+0xcc/0xe8
el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8
[...]
el1_dbg+0x2c/0x90
el1h_64_sync_handler+0xcc/0xe8
el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8
arm64_enter_el1_dbg.isra.0+0x14/0x20
el1_dbg+0x2c/0x90
el1h_64_sync_handler+0xcc/0xe8
el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8
arm64_enter_el1_dbg.isra.0+0x14/0x20
el1_dbg+0x2c/0x90
el1h_64_sync_handler+0xcc/0xe8
el1h_64_sync+0x64/0x68
__rcu_irq_enter_check_tick+0x0/0x1b8
el1_interrupt+0x28/0x60
el1h_64_irq_handler+0x18/0x28
el1h_64_irq+0x64/0x68
__ftrace_set_clr_event_nolock+0x98/0x198
__ftrace_set_clr_event+0x58/0x80
system_enable_write+0x144/0x178
vfs_write+0x174/0x738
ksys_write+0xd0/0x188
__arm64_sys_write+0x4c/0x60
invoke_syscall+0x64/0x180
el0_svc_common.constprop.0+0x84/0x160
do_el0_svc+0x48/0xe8
el0_svc+0x34/0xd0
el0t_64_sync_handler+0xb8/0xc0
el0t_64_sync+0x190/0x194
SMP: stopping secondary CPUs
Kernel Offset: 0x28da86000000 from 0xffff800008000000
PHYS_OFFSET: 0xfffff76600000000
CPU features: 0x00000,01a00100,0000421b
Memory Limit: none
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
drivers/perf: hisi: Don't migrate perf to the CPU going to teardown
The driver needs to migrate the perf context if the current using CPU going
to teardown. By the time calling the cpuhp::teardown() callback the
cpu_online_mask() hasn't updated yet and still includes the CPU going to
teardown. In current driver's implementation we may migrate the context
to the teardown CPU and leads to the below calltrace:
...
[ 368.104662][ T932] task:cpuhp/0 state:D stack: 0 pid: 15 ppid: 2 flags:0x00000008
[ 368.113699][ T932] Call trace:
[ 368.116834][ T932] __switch_to+0x7c/0xbc
[ 368.120924][ T932] __schedule+0x338/0x6f0
[ 368.125098][ T932] schedule+0x50/0xe0
[ 368.128926][ T932] schedule_preempt_disabled+0x18/0x24
[ 368.134229][ T932] __mutex_lock.constprop.0+0x1d4/0x5dc
[ 368.139617][ T932] __mutex_lock_slowpath+0x1c/0x30
[ 368.144573][ T932] mutex_lock+0x50/0x60
[ 368.148579][ T932] perf_pmu_migrate_context+0x84/0x2b0
[ 368.153884][ T932] hisi_pcie_pmu_offline_cpu+0x90/0xe0 [hisi_pcie_pmu]
[ 368.160579][ T932] cpuhp_invoke_callback+0x2a0/0x650
[ 368.165707][ T932] cpuhp_thread_fun+0xe4/0x190
[ 368.170316][ T932] smpboot_thread_fn+0x15c/0x1a0
[ 368.175099][ T932] kthread+0x108/0x13c
[ 368.179012][ T932] ret_from_fork+0x10/0x18
...
Use function cpumask_any_but() to find one correct active cpu to fixes
this issue.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07