Linux: >> Linux Kernel >> 6.1.16 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
media: netup_unidvb: fix use-after-free at del_timer()
When Universal DVB card is detaching, netup_unidvb_dma_fini()
uses del_timer() to stop dma->timeout timer. But when timer
handler netup_unidvb_dma_timeout() is running, del_timer()
could not stop it. As a result, the use-after-free bug could
happen. The process is shown below:
(cleanup routine) | (timer routine)
| mod_timer(&dev->tx_sim_timer, ..)
netup_unidvb_finidev() | (wait a time)
netup_unidvb_dma_fini() | netup_unidvb_dma_timeout()
del_timer(&dma->timeout); |
| ndev->pci_dev->dev //USE
Fix by changing del_timer() to del_timer_sync().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
media: az6007: Fix null-ptr-deref in az6007_i2c_xfer()
In az6007_i2c_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach az6007_i2c_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.
Similar commit:
commit 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix memleak due to fentry attach failure
If it fails to attach fentry, the allocated bpf trampoline image will be
left in the system. That can be verified by checking /proc/kallsyms.
This meamleak can be verified by a simple bpf program as follows:
SEC("fentry/trap_init")
int fentry_run()
{
return 0;
}
It will fail to attach trap_init because this function is freed after
kernel init, and then we can find the trampoline image is left in the
system by checking /proc/kallsyms.
$ tail /proc/kallsyms
ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf]
ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf]
$ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'"
[2522] FUNC 'trap_init' type_id=119 linkage=static
$ echo $((6442453466 & 0x7fffffff))
2522
Note that there are two left bpf trampoline images, that is because the
libbpf will fallback to raw tracepoint if -EINVAL is returned.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
jfs: jfs_dmap: Validate db_l2nbperpage while mounting
In jfs_dmap.c at line 381, BLKTODMAP is used to get a logical block
number inside dbFree(). db_l2nbperpage, which is the log2 number of
blocks per page, is passed as an argument to BLKTODMAP which uses it
for shifting.
Syzbot reported a shift out-of-bounds crash because db_l2nbperpage is
too big. This happens because the large value is set without any
validation in dbMount() at line 181.
Thus, make sure that db_l2nbperpage is correct while mounting.
Max number of blocks per page = Page size / Min block size
=> log2(Max num_block per page) = log2(Page size / Min block size)
= log2(Page size) - log2(Min block size)
=> Max db_l2nbperpage = L2PSIZE - L2MINBLOCKSIZE
CVSS Score
7.1
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
ublk: fail to recover device if queue setup is interrupted
In ublk_ctrl_end_recovery(), if wait_for_completion_interruptible() is
interrupted by signal, queues aren't setup successfully yet, so we
have to fail UBLK_CMD_END_USER_RECOVERY, otherwise kernel oops can be
triggered.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Load L1's TSC multiplier based on L1 state, not L2 state
When emulating nested VM-Exit, load L1's TSC multiplier if L1's desired
ratio doesn't match the current ratio, not if the ratio L1 is using for
L2 diverges from the default. Functionally, the end result is the same
as KVM will run L2 with L1's multiplier if L2's multiplier is the default,
i.e. checking that L1's multiplier is loaded is equivalent to checking if
L2 has a non-default multiplier.
However, the assertion that TSC scaling is exposed to L1 is flawed, as
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: 10 PID: 206939 at arch/x86/kvm/svm/nested.c:1105
nested_svm_vmexit+0x6af/0x720 [kvm_amd]
Call Trace:
nested_svm_exit_handled+0x102/0x1f0 [kvm_amd]
svm_handle_exit+0xb9/0x180 [kvm_amd]
kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm]
kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm]
? trace_hardirqs_off+0x4d/0xa0
__se_sys_ioctl+0x7a/0xc0
__x64_sys_ioctl+0x21/0x30
do_syscall_64+0x41/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Unlike the nested VMRUN path, hoisting the svm->tsc_scaling_enabled check
into the if-statement is wrong as KVM needs to ensure L1's multiplier is
loaded in the above scenario. Alternatively, the WARN_ON() could simply
be deleted, but that would make KVM's behavior even more subtle, e.g. it's
not immediately obvious why it's safe to write MSR_AMD64_TSC_RATIO when
checking only tsc_ratio_msr.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211_hwsim: Fix possible NULL dereference
In a call to mac80211_hwsim_select_tx_link() the sta pointer might
be NULL, thus need to check that it is not NULL before accessing it.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()
r5l_flush_stripe_to_raid() will check if the list 'flushing_ios' is
empty, and then submit 'flush_bio', however, r5l_log_flush_endio()
is clearing the list first and then clear the bio, which will cause
null-ptr-deref:
T1: submit flush io
raid5d
handle_active_stripes
r5l_flush_stripe_to_raid
// list is empty
// add 'io_end_ios' to the list
bio_init
submit_bio
// io1
T2: io1 is done
r5l_log_flush_endio
list_splice_tail_init
// clear the list
T3: submit new flush io
...
r5l_flush_stripe_to_raid
// list is empty
// add 'io_end_ios' to the list
bio_init
bio_uninit
// clear bio->bi_blkg
submit_bio
// null-ptr-deref
Fix this problem by clearing bio before clearing the list in
r5l_log_flush_endio().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: slab-out-of-bounds read in brcmf_get_assoc_ies()
Fix a slab-out-of-bounds read that occurs in kmemdup() called from
brcmf_get_assoc_ies().
The bug could occur when assoc_info->req_len, data from a URB provided
by a USB device, is bigger than the size of buffer which is defined as
WL_EXTRA_BUF_MAX.
Add the size check for req_len/resp_len of assoc_info.
Found by a modified version of syzkaller.
[ 46.592467][ T7] ==================================================================
[ 46.594687][ T7] BUG: KASAN: slab-out-of-bounds in kmemdup+0x3e/0x50
[ 46.596572][ T7] Read of size 3014656 at addr ffff888019442000 by task kworker/0:1/7
[ 46.598575][ T7]
[ 46.599157][ T7] CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #145
[ 46.601333][ T7] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 46.604360][ T7] Workqueue: events brcmf_fweh_event_worker
[ 46.605943][ T7] Call Trace:
[ 46.606584][ T7] dump_stack_lvl+0x8e/0xd1
[ 46.607446][ T7] print_address_description.constprop.0.cold+0x93/0x334
[ 46.608610][ T7] ? kmemdup+0x3e/0x50
[ 46.609341][ T7] kasan_report.cold+0x79/0xd5
[ 46.610151][ T7] ? kmemdup+0x3e/0x50
[ 46.610796][ T7] kasan_check_range+0x14e/0x1b0
[ 46.611691][ T7] memcpy+0x20/0x60
[ 46.612323][ T7] kmemdup+0x3e/0x50
[ 46.612987][ T7] brcmf_get_assoc_ies+0x967/0xf60
[ 46.613904][ T7] ? brcmf_notify_vif_event+0x3d0/0x3d0
[ 46.614831][ T7] ? lock_chain_count+0x20/0x20
[ 46.615683][ T7] ? mark_lock.part.0+0xfc/0x2770
[ 46.616552][ T7] ? lock_chain_count+0x20/0x20
[ 46.617409][ T7] ? mark_lock.part.0+0xfc/0x2770
[ 46.618244][ T7] ? lock_chain_count+0x20/0x20
[ 46.619024][ T7] brcmf_bss_connect_done.constprop.0+0x241/0x2e0
[ 46.620019][ T7] ? brcmf_parse_configure_security.isra.0+0x2a0/0x2a0
[ 46.620818][ T7] ? __lock_acquire+0x181f/0x5790
[ 46.621462][ T7] brcmf_notify_connect_status+0x448/0x1950
[ 46.622134][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 46.622736][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0
[ 46.623390][ T7] ? find_held_lock+0x2d/0x110
[ 46.623962][ T7] ? brcmf_fweh_event_worker+0x19f/0xc60
[ 46.624603][ T7] ? mark_held_locks+0x9f/0xe0
[ 46.625145][ T7] ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0
[ 46.625871][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0
[ 46.626545][ T7] brcmf_fweh_call_event_handler.isra.0+0x90/0x100
[ 46.627338][ T7] brcmf_fweh_event_worker+0x557/0xc60
[ 46.627962][ T7] ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
[ 46.628736][ T7] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 46.629396][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 46.629970][ T7] ? lockdep_hardirqs_on_prepare+0x273/0x3e0
[ 46.630649][ T7] process_one_work+0x92b/0x1460
[ 46.631205][ T7] ? pwq_dec_nr_in_flight+0x330/0x330
[ 46.631821][ T7] ? rwlock_bug.part.0+0x90/0x90
[ 46.632347][ T7] worker_thread+0x95/0xe00
[ 46.632832][ T7] ? __kthread_parkme+0x115/0x1e0
[ 46.633393][ T7] ? process_one_work+0x1460/0x1460
[ 46.633957][ T7] kthread+0x3a1/0x480
[ 46.634369][ T7] ? set_kthread_struct+0x120/0x120
[ 46.634933][ T7] ret_from_fork+0x1f/0x30
[ 46.635431][ T7]
[ 46.635687][ T7] Allocated by task 7:
[ 46.636151][ T7] kasan_save_stack+0x1b/0x40
[ 46.636628][ T7] __kasan_kmalloc+0x7c/0x90
[ 46.637108][ T7] kmem_cache_alloc_trace+0x19e/0x330
[ 46.637696][ T7] brcmf_cfg80211_attach+0x4a0/0x4040
[ 46.638275][ T7] brcmf_attach+0x389/0xd40
[ 46.638739][ T7] brcmf_usb_probe+0x12de/0x1690
[ 46.639279][ T7] usb_probe_interface+0x2aa/0x760
[ 46.639820][ T7] really_probe+0x205/0xb70
[ 46.640342][ T7] __driver_probe_device+0
---truncated---
CVSS Score
7.1
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
Here is the stack where we allocate percpu counter block:
+-< __alloc_percpu
+-< xt_percpu_counter_alloc
+-< find_check_entry # {arp,ip,ip6}_tables.c
+-< translate_table
And it can be leaked on this code path:
+-> ip6t_register_table
+-> translate_table # allocates percpu counter block
+-> xt_register_table # fails
there is no freeing of the counter block on xt_register_table fail.
Note: xt_percpu_counter_free should be called to free it like we do in
do_replace through cleanup_entry helper (or in __ip6t_unregister_table).
Probability of hitting this error path is low AFAICS (xt_register_table
can only return ENOMEM here, as it is not replacing anything, as we are
creating new netns, and it is hard to imagine that all previous
allocations succeeded and after that one in xt_register_table failed).
But it's worth fixing even the rare leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15