Linux: >> Linux Kernel >> 4.16 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
seg6: Fix validation of nexthop addresses
The kernel currently validates that the length of the provided nexthop
address does not exceed the specified length. This can lead to the
kernel reading uninitialized memory if user space provided a shorter
length than the specified one.
Fix by validating that the provided length exactly matches the specified
one.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-10
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: at91: Fix possible out-of-boundary access
at91_gpio_probe() doesn't check that given OF alias is not available or
something went wrong when trying to get it. This might have consequences
when accessing gpio_chips array with that value as an index. Note, that
BUG() can be compiled out and hence won't actually perform the required
checks.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-07-10
In the Linux kernel, the following vulnerability has been resolved:
bpf: Avoid __bpf_prog_ret0_warn when jit fails
syzkaller reported an issue:
WARNING: CPU: 3 PID: 217 at kernel/bpf/core.c:2357 __bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357
Modules linked in:
CPU: 3 UID: 0 PID: 217 Comm: kworker/u32:6 Not tainted 6.15.0-rc4-syzkaller-00040-g8bac8898fe39
RIP: 0010:__bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357
Call Trace:
<TASK>
bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
__bpf_prog_run include/linux/filter.h:718 [inline]
bpf_prog_run include/linux/filter.h:725 [inline]
cls_bpf_classify+0x74a/0x1110 net/sched/cls_bpf.c:105
...
When creating bpf program, 'fp->jit_requested' depends on bpf_jit_enable.
This issue is triggered because of CONFIG_BPF_JIT_ALWAYS_ON is not set
and bpf_jit_enable is set to 1, causing the arch to attempt JIT the prog,
but jit failed due to FAULT_INJECTION. As a result, incorrectly
treats the program as valid, when the program runs it calls
`__bpf_prog_ret0_warn` and triggers the WARN_ON_ONCE(1).
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-10
In the Linux kernel, the following vulnerability has been resolved:
btrfs: exit after state insertion failure at btrfs_convert_extent_bit()
If insert_state() state failed it returns an error pointer and we call
extent_io_tree_panic() which will trigger a BUG() call. However if
CONFIG_BUG is disabled, which is an uncommon and exotic scenario, then
we fallthrough and call cache_state() which will dereference the error
pointer, resulting in an invalid memory access.
So jump to the 'out' label after calling extent_io_tree_panic(), it also
makes the code more clear besides dealing with the exotic scenario where
CONFIG_BUG is disabled.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-10
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: b53: do not enable EEE on bcm63xx
BCM63xx internal switches do not support EEE, but provide multiple RGMII
ports where external PHYs may be connected. If one of these PHYs are EEE
capable, we may try to enable EEE for the MACs, which then hangs the
system on access of the (non-existent) EEE registers.
Fix this by checking if the switch actually supports EEE before
attempting to configure it.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-10
In the Linux kernel, the following vulnerability has been resolved:
riscv: save the SR_SUM status over switches
When threads/tasks are switched we need to ensure the old execution's
SR_SUM state is saved and the new thread has the old SR_SUM state
restored.
The issue was seen under heavy load especially with the syz-stress tool
running, with crashes as follows in schedule_tail:
Unable to handle kernel access to user memory without uaccess routines
at virtual address 000000002749f0d0
Oops [#1]
Modules linked in:
CPU: 1 PID: 4875 Comm: syz-executor.0 Not tainted
5.12.0-rc2-syzkaller-00467-g0d7588ab9ef9 #0
Hardware name: riscv-virtio,qemu (DT)
epc : schedule_tail+0x72/0xb2 kernel/sched/core.c:4264
ra : task_pid_vnr include/linux/sched.h:1421 [inline]
ra : schedule_tail+0x70/0xb2 kernel/sched/core.c:4264
epc : ffffffe00008c8b0 ra : ffffffe00008c8ae sp : ffffffe025d17ec0
gp : ffffffe005d25378 tp : ffffffe00f0d0000 t0 : 0000000000000000
t1 : 0000000000000001 t2 : 00000000000f4240 s0 : ffffffe025d17ee0
s1 : 000000002749f0d0 a0 : 000000000000002a a1 : 0000000000000003
a2 : 1ffffffc0cfac500 a3 : ffffffe0000c80cc a4 : 5ae9db91c19bbe00
a5 : 0000000000000000 a6 : 0000000000f00000 a7 : ffffffe000082eba
s2 : 0000000000040000 s3 : ffffffe00eef96c0 s4 : ffffffe022c77fe0
s5 : 0000000000004000 s6 : ffffffe067d74e00 s7 : ffffffe067d74850
s8 : ffffffe067d73e18 s9 : ffffffe067d74e00 s10: ffffffe00eef96e8
s11: 000000ae6cdf8368 t3 : 5ae9db91c19bbe00 t4 : ffffffc4043cafb2
t5 : ffffffc4043cafba t6 : 0000000000040000
status: 0000000000000120 badaddr: 000000002749f0d0 cause:
000000000000000f
Call Trace:
[<ffffffe00008c8b0>] schedule_tail+0x72/0xb2 kernel/sched/core.c:4264
[<ffffffe000005570>] ret_from_exception+0x0/0x14
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace b5f8f9231dc87dda ]---
The issue comes from the put_user() in schedule_tail
(kernel/sched/core.c) doing the following:
asmlinkage __visible void schedule_tail(struct task_struct *prev)
{
...
if (current->set_child_tid)
put_user(task_pid_vnr(current), current->set_child_tid);
...
}
the put_user() macro causes the code sequence to come out as follows:
1: __enable_user_access()
2: reg = task_pid_vnr(current);
3: *current->set_child_tid = reg;
4: __disable_user_access()
The problem is that we may have a sleeping function as argument which
could clear SR_SUM causing the panic above. This was fixed by
evaluating the argument of the put_user() macro outside the user-enabled
section in commit 285a76bb2cf5 ("riscv: evaluate put_user() arg before
enabling user access")"
In order for riscv to take advantage of unsafe_get/put_XXX() macros and
to avoid the same issue we had with put_user() and sleeping functions we
must ensure code flow can go through switch_to() from within a region of
code with SR_SUM enabled and come back with SR_SUM still enabled. This
patch addresses the problem allowing future work to enable full use of
unsafe_get/put_XXX() macros without needing to take a CSR bit flip cost
on every access. Make switch_to() save and restore SR_SUM.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-09
In the Linux kernel, the following vulnerability has been resolved:
tty: serial: uartlite: register uart driver in init
When two instances of uart devices are probing, a concurrency race can
occur. If one thread calls uart_register_driver function, which first
allocates and assigns memory to 'uart_state' member of uart_driver
structure, the other instance can bypass uart driver registration and
call ulite_assign. This calls uart_add_one_port, which expects the uart
driver to be fully initialized. This leads to a kernel panic due to a
null pointer dereference:
[ 8.143581] BUG: kernel NULL pointer dereference, address: 00000000000002b8
[ 8.156982] #PF: supervisor write access in kernel mode
[ 8.156984] #PF: error_code(0x0002) - not-present page
[ 8.156986] PGD 0 P4D 0
...
[ 8.180668] RIP: 0010:mutex_lock+0x19/0x30
[ 8.188624] Call Trace:
[ 8.188629] ? __die_body.cold+0x1a/0x1f
[ 8.195260] ? page_fault_oops+0x15c/0x290
[ 8.209183] ? __irq_resolve_mapping+0x47/0x80
[ 8.209187] ? exc_page_fault+0x64/0x140
[ 8.209190] ? asm_exc_page_fault+0x22/0x30
[ 8.209196] ? mutex_lock+0x19/0x30
[ 8.223116] uart_add_one_port+0x60/0x440
[ 8.223122] ? proc_tty_register_driver+0x43/0x50
[ 8.223126] ? tty_register_driver+0x1ca/0x1e0
[ 8.246250] ulite_probe+0x357/0x4b0 [uartlite]
To prevent it, move uart driver registration in to init function. This
will ensure that uart_driver is always registered when probe function
is called.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-09
In the Linux kernel, the following vulnerability has been resolved:
bcache: fix NULL pointer in cache_set_flush()
1. LINE#1794 - LINE#1887 is some codes about function of
bch_cache_set_alloc().
2. LINE#2078 - LINE#2142 is some codes about function of
register_cache_set().
3. register_cache_set() will call bch_cache_set_alloc() in LINE#2098.
1794 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1795 {
...
1860 if (!(c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL)) ||
1861 mempool_init_slab_pool(&c->search, 32, bch_search_cache) ||
1862 mempool_init_kmalloc_pool(&c->bio_meta, 2,
1863 sizeof(struct bbio) + sizeof(struct bio_vec) *
1864 bucket_pages(c)) ||
1865 mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
1866 bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio),
1867 BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER) ||
1868 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1869 !(c->moving_gc_wq = alloc_workqueue("bcache_gc",
1870 WQ_MEM_RECLAIM, 0)) ||
1871 bch_journal_alloc(c) ||
1872 bch_btree_cache_alloc(c) ||
1873 bch_open_buckets_alloc(c) ||
1874 bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
1875 goto err;
^^^^^^^^
1876
...
1883 return c;
1884 err:
1885 bch_cache_set_unregister(c);
^^^^^^^^^^^^^^^^^^^^^^^^^^^
1886 return NULL;
1887 }
...
2078 static const char *register_cache_set(struct cache *ca)
2079 {
...
2098 c = bch_cache_set_alloc(&ca->sb);
2099 if (!c)
2100 return err;
^^^^^^^^^^
...
2128 ca->set = c;
2129 ca->set->cache[ca->sb.nr_this_dev] = ca;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
2138 return NULL;
2139 err:
2140 bch_cache_set_unregister(c);
2141 return err;
2142 }
(1) If LINE#1860 - LINE#1874 is true, then do 'goto err'(LINE#1875) and
call bch_cache_set_unregister()(LINE#1885).
(2) As (1) return NULL(LINE#1886), LINE#2098 - LINE#2100 would return.
(3) As (2) has returned, LINE#2128 - LINE#2129 would do *not* give the
value to c->cache[], it means that c->cache[] is NULL.
LINE#1624 - LINE#1665 is some codes about function of cache_set_flush().
As (1), in LINE#1885 call
bch_cache_set_unregister()
---> bch_cache_set_stop()
---> closure_queue()
-.-> cache_set_flush() (as below LINE#1624)
1624 static void cache_set_flush(struct closure *cl)
1625 {
...
1654 for_each_cache(ca, c, i)
1655 if (ca->alloc_thread)
^^
1656 kthread_stop(ca->alloc_thread);
...
1665 }
(4) In LINE#1655 ca is NULL(see (3)) in cache_set_flush() then the
kernel crash occurred as below:
[ 846.712887] bcache: register_cache() error drbd6: cannot allocate memory
[ 846.713242] bcache: register_bcache() error : failed to register device
[ 846.713336] bcache: cache_set_free() Cache set 2f84bdc1-498a-4f2f-98a7-01946bf54287 unregistered
[ 846.713768] BUG: unable to handle kernel NULL pointer dereference at 00000000000009f8
[ 846.714790] PGD 0 P4D 0
[ 846.715129] Oops: 0000 [#1] SMP PTI
[ 846.715472] CPU: 19 PID: 5057 Comm: kworker/19:16 Kdump: loaded Tainted: G OE --------- - - 4.18.0-147.5.1.el8_1.5es.3.x86_64 #1
[ 846.716082] Hardware name: ESPAN GI-25212/X11DPL-i, BIOS 2.1 06/15/2018
[ 846.716451] Workqueue: events cache_set_flush [bcache]
[ 846.716808] RIP: 0010:cache_set_flush+0xc9/0x1b0 [bcache]
[ 846.717155] Code: 00 4c 89 a5 b0 03 00 00 48 8b 85 68 f6 ff ff a8 08 0f 84 88 00 00 00 31 db 66 83 bd 3c f7 ff ff 00 48 8b 85 48 ff ff ff 74 28 <48> 8b b8 f8 09 00 0
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-09
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix use-after-free in vhci_flush()
syzbot reported use-after-free in vhci_flush() without repro. [0]
From the splat, a thread close()d a vhci file descriptor while
its device was being used by iotcl() on another thread.
Once the last fd refcnt is released, vhci_release() calls
hci_unregister_dev(), hci_free_dev(), and kfree() for struct
vhci_data, which is set to hci_dev->dev->driver_data.
The problem is that there is no synchronisation after unlinking
hdev from hci_dev_list in hci_unregister_dev(). There might be
another thread still accessing the hdev which was fetched before
the unlink operation.
We can use SRCU for such synchronisation.
Let's run hci_dev_reset() under SRCU and wait for its completion
in hci_unregister_dev().
Another option would be to restore hci_dev->destruct(), which was
removed in commit 587ae086f6e4 ("Bluetooth: Remove unused
hci-destruct cb"). However, this would not be a good solution, as
we should not run hci_unregister_dev() while there are in-flight
ioctl() requests, which could lead to another data-race KCSAN splat.
Note that other drivers seem to have the same problem, for exmaple,
virtbt_remove().
[0]:
BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline]
BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937
Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718
CPU: 1 UID: 0 PID: 6718 Comm: syz.1.219 Not tainted 6.16.0-rc1-syzkaller-00196-g08207f42d3ff #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xd2/0x2b0 mm/kasan/report.c:521
kasan_report+0x118/0x150 mm/kasan/report.c:634
skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline]
skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937
skb_queue_purge include/linux/skbuff.h:3368 [inline]
vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69
hci_dev_do_reset net/bluetooth/hci_core.c:552 [inline]
hci_dev_reset+0x420/0x5c0 net/bluetooth/hci_core.c:592
sock_do_ioctl+0xd9/0x300 net/socket.c:1190
sock_ioctl+0x576/0x790 net/socket.c:1311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf5b98e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcf5c7b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcf5bbb6160 RCX: 00007fcf5b98e929
RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000009
RBP: 00007fcf5ba10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcf5bbb6160 R15: 00007ffd6353d528
</TASK>
Allocated by task 6535:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
vhci_open+0x57/0x360 drivers/bluetooth/hci_vhci.c:635
misc_open+0x2bc/0x330 drivers/char/misc.c:161
chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414
do_dentry_open+0xdf0/0x1970 fs/open.c:964
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/name
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-09
In the Linux kernel, the following vulnerability has been resolved:
atm: Release atm_dev_mutex after removing procfs in atm_dev_deregister().
syzbot reported a warning below during atm_dev_register(). [0]
Before creating a new device and procfs/sysfs for it, atm_dev_register()
looks up a duplicated device by __atm_dev_lookup(). These operations are
done under atm_dev_mutex.
However, when removing a device in atm_dev_deregister(), it releases the
mutex just after removing the device from the list that __atm_dev_lookup()
iterates over.
So, there will be a small race window where the device does not exist on
the device list but procfs/sysfs are still not removed, triggering the
splat.
Let's hold the mutex until procfs/sysfs are removed in
atm_dev_deregister().
[0]:
proc_dir_entry 'atm/atmtcp:0' already registered
WARNING: CPU: 0 PID: 5919 at fs/proc/generic.c:377 proc_register+0x455/0x5f0 fs/proc/generic.c:377
Modules linked in:
CPU: 0 UID: 0 PID: 5919 Comm: syz-executor284 Not tainted 6.16.0-rc2-syzkaller-00047-g52da431bf03b #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:proc_register+0x455/0x5f0 fs/proc/generic.c:377
Code: 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 a2 01 00 00 48 8b 44 24 10 48 c7 c7 20 c0 c2 8b 48 8b b0 d8 00 00 00 e8 0c 02 1c ff 90 <0f> 0b 90 90 48 c7 c7 80 f2 82 8e e8 0b de 23 09 48 8b 4c 24 28 48
RSP: 0018:ffffc9000466fa30 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817ae248
RDX: ffff888026280000 RSI: ffffffff817ae255 RDI: 0000000000000001
RBP: ffff8880232bed48 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888076ed2140
R13: dffffc0000000000 R14: ffff888078a61340 R15: ffffed100edda444
FS: 00007f38b3b0c6c0(0000) GS:ffff888124753000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f38b3bdf953 CR3: 0000000076d58000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
proc_create_data+0xbe/0x110 fs/proc/generic.c:585
atm_proc_dev_register+0x112/0x1e0 net/atm/proc.c:361
atm_dev_register+0x46d/0x890 net/atm/resources.c:113
atmtcp_create+0x77/0x210 drivers/atm/atmtcp.c:369
atmtcp_attach drivers/atm/atmtcp.c:403 [inline]
atmtcp_ioctl+0x2f9/0xd60 drivers/atm/atmtcp.c:464
do_vcc_ioctl+0x12c/0x930 net/atm/ioctl.c:159
sock_do_ioctl+0x115/0x280 net/socket.c:1190
sock_ioctl+0x227/0x6b0 net/socket.c:1311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f38b3b74459
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f38b3b0c198 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f38b3bfe318 RCX: 00007f38b3b74459
RDX: 0000000000000000 RSI: 0000000000006180 RDI: 0000000000000005
RBP: 00007f38b3bfe310 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 65732f636f72702f R11: 0000000000000246 R12: 00007f38b3bcb0ac
R13: 00007f38b3b0c1a0 R14: 0000200000000200 R15: 00007f38b3bcb03b
</TASK>
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-09