Linux: >> Linux Kernel >> 6.1.100 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
do_change_type(): refuse to operate on unmounted/not ours mounts
Ensure that propagation settings can only be changed for mounts located
in the caller's mount namespace. This change aligns permission checking
with the rest of mount(2).
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-30
In the Linux kernel, the following vulnerability has been resolved:
mptcp: make fallback action and fallback decision atomic
Syzkaller reported the following splat:
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 __mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 check_fully_established net/mptcp/options.c:982 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
Modules linked in:
CPU: 1 UID: 0 PID: 7704 Comm: syz.3.1419 Not tainted 6.16.0-rc3-gbd5ce2324dba #20 PREEMPT(voluntary)
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
RIP: 0010:mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
RIP: 0010:check_fully_established net/mptcp/options.c:982 [inline]
RIP: 0010:mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
Code: 24 18 e8 bb 2a 00 fd e9 1b df ff ff e8 b1 21 0f 00 e8 ec 5f c4 fc 44 0f b7 ac 24 b0 00 00 00 e9 54 f1 ff ff e8 d9 5f c4 fc 90 <0f> 0b 90 e9 b8 f4 ff ff e8 8b 2a 00 fd e9 8d e6 ff ff e8 81 2a 00
RSP: 0018:ffff8880a3f08448 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880180a8000 RCX: ffffffff84afcf45
RDX: ffff888090223700 RSI: ffffffff84afdaa7 RDI: 0000000000000001
RBP: ffff888017955780 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880180a8910 R14: ffff8880a3e9d058 R15: 0000000000000000
FS: 00005555791b8500(0000) GS:ffff88811c495000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2800b7 CR3: 0000000058e44000 CR4: 0000000000350ef0
Call Trace:
<IRQ>
tcp_reset+0x26f/0x2b0 net/ipv4/tcp_input.c:4432
tcp_validate_incoming+0x1057/0x1b60 net/ipv4/tcp_input.c:5975
tcp_rcv_established+0x5b5/0x21f0 net/ipv4/tcp_input.c:6166
tcp_v4_do_rcv+0x5dc/0xa70 net/ipv4/tcp_ipv4.c:1925
tcp_v4_rcv+0x3473/0x44a0 net/ipv4/tcp_ipv4.c:2363
ip_protocol_deliver_rcu+0xba/0x480 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x2f1/0x500 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_local_deliver+0x1be/0x560 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:469 [inline]
ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_rcv+0x514/0x810 net/ipv4/ip_input.c:567
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5975
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6088
process_backlog+0x301/0x1360 net/core/dev.c:6440
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7453
napi_poll net/core/dev.c:7517 [inline]
net_rx_action+0xb44/0x1010 net/core/dev.c:7644
handle_softirqs+0x1d0/0x770 kernel/softirq.c:579
do_softirq+0x3f/0x90 kernel/softirq.c:480
</IRQ>
<TASK>
__local_bh_enable_ip+0xed/0x110 kernel/softirq.c:407
local_bh_enable include/linux/bottom_half.h:33 [inline]
inet_csk_listen_stop+0x2c5/0x1070 net/ipv4/inet_connection_sock.c:1524
mptcp_check_listen_stop.part.0+0x1cc/0x220 net/mptcp/protocol.c:2985
mptcp_check_listen_stop net/mptcp/mib.h:118 [inline]
__mptcp_close+0x9b9/0xbd0 net/mptcp/protocol.c:3000
mptcp_close+0x2f/0x140 net/mptcp/protocol.c:3066
inet_release+0xed/0x200 net/ipv4/af_inet.c:435
inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:487
__sock_release+0xb3/0x270 net/socket.c:649
sock_close+0x1c/0x30 net/socket.c:1439
__fput+0x402/0xb70 fs/file_table.c:465
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xd4
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
HID: core: do not bypass hid_hw_raw_request
hid_hw_raw_request() is actually useful to ensure the provided buffer
and length are valid. Directly calling in the low level transport driver
function bypassed those checks and allowed invalid paramto be used.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
HID: core: ensure the allocated report buffer can contain the reserved report ID
When the report ID is not used, the low level transport drivers expect
the first byte to be 0. However, currently the allocated buffer not
account for that extra byte, meaning that instead of having 8 guaranteed
bytes for implement to be working, we only have 7.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: configfs: Fix OOB read on empty string write
When writing an empty string to either 'qw_sign' or 'landingPage'
sysfs attributes, the store functions attempt to access page[l - 1]
before validating that the length 'l' is greater than zero.
This patch fixes the vulnerability by adding a check at the beginning
of os_desc_qw_sign_store() and webusb_landingPage_store() to handle
the zero-length input case gracefully by returning immediately.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
comedi: das6402: Fix bit shift out of bounds
When checking for a supported IRQ number, the following test is used:
/* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */
if ((1 << it->options[1]) & 0x8cec) {
However, `it->options[i]` is an unchecked `int` value from userspace, so
the shift amount could be negative or out of bounds. Fix the test by
requiring `it->options[1]` to be within bounds before proceeding with
the original test. Valid `it->options[1]` values that select the IRQ
will be in the range [1,15]. The value 0 explicitly disables the use of
interrupts.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
comedi: das16m1: Fix bit shift out of bounds
When checking for a supported IRQ number, the following test is used:
/* only irqs 2, 3, 4, 5, 6, 7, 10, 11, 12, 14, and 15 are valid */
if ((1 << it->options[1]) & 0xdcfc) {
However, `it->options[i]` is an unchecked `int` value from userspace, so
the shift amount could be negative or out of bounds. Fix the test by
requiring `it->options[1]` to be within bounds before proceeding with
the original test.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
iio: accel: fxls8962af: Fix use after free in fxls8962af_fifo_flush
fxls8962af_fifo_flush() uses indio_dev->active_scan_mask (with
iio_for_each_active_channel()) without making sure the indio_dev
stays in buffer mode.
There is a race if indio_dev exits buffer mode in the middle of the
interrupt that flushes the fifo. Fix this by calling
synchronize_irq() to ensure that no interrupt is currently running when
disabling buffer mode.
Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
[...]
_find_first_bit_le from fxls8962af_fifo_flush+0x17c/0x290
fxls8962af_fifo_flush from fxls8962af_interrupt+0x80/0x178
fxls8962af_interrupt from irq_thread_fn+0x1c/0x7c
irq_thread_fn from irq_thread+0x110/0x1f4
irq_thread from kthread+0xe0/0xfc
kthread from ret_from_fork+0x14/0x2c
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
soc: aspeed: lpc-snoop: Don't disable channels that aren't enabled
Mitigate e.g. the following:
# echo 1e789080.lpc-snoop > /sys/bus/platform/drivers/aspeed-lpc-snoop/unbind
...
[ 120.363594] Unable to handle kernel NULL pointer dereference at virtual address 00000004 when write
[ 120.373866] [00000004] *pgd=00000000
[ 120.377910] Internal error: Oops: 805 [#1] SMP ARM
[ 120.383306] CPU: 1 UID: 0 PID: 315 Comm: sh Not tainted 6.15.0-rc1-00009-g926217bc7d7d-dirty #20 NONE
...
[ 120.679543] Call trace:
[ 120.679559] misc_deregister from aspeed_lpc_snoop_remove+0x84/0xac
[ 120.692462] aspeed_lpc_snoop_remove from platform_remove+0x28/0x38
[ 120.700996] platform_remove from device_release_driver_internal+0x188/0x200
...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack: fix crash due to removal of uninitialised entry
A crash in conntrack was reported while trying to unlink the conntrack
entry from the hash bucket list:
[exception RIP: __nf_ct_delete_from_lists+172]
[..]
#7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack]
#8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack]
#9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack]
[..]
The nf_conn struct is marked as allocated from slab but appears to be in
a partially initialised state:
ct hlist pointer is garbage; looks like the ct hash value
(hence crash).
ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected
ct->timeout is 30000 (=30s), which is unexpected.
Everything else looks like normal udp conntrack entry. If we ignore
ct->status and pretend its 0, the entry matches those that are newly
allocated but not yet inserted into the hash:
- ct hlist pointers are overloaded and store/cache the raw tuple hash
- ct->timeout matches the relative time expected for a new udp flow
rather than the absolute 'jiffies' value.
If it were not for the presence of IPS_CONFIRMED,
__nf_conntrack_find_get() would have skipped the entry.
Theory is that we did hit following race:
cpu x cpu y cpu z
found entry E found entry E
E is expired <preemption>
nf_ct_delete()
return E to rcu slab
init_conntrack
E is re-inited,
ct->status set to 0
reply tuplehash hnnode.pprev
stores hash value.
cpu y found E right before it was deleted on cpu x.
E is now re-inited on cpu z. cpu y was preempted before
checking for expiry and/or confirm bit.
->refcnt set to 1
E now owned by skb
->timeout set to 30000
If cpu y were to resume now, it would observe E as
expired but would skip E due to missing CONFIRMED bit.
nf_conntrack_confirm gets called
sets: ct->status |= CONFIRMED
This is wrong: E is not yet added
to hashtable.
cpu y resumes, it observes E as expired but CONFIRMED:
<resumes>
nf_ct_expired()
-> yes (ct->timeout is 30s)
confirmed bit set.
cpu y will try to delete E from the hashtable:
nf_ct_delete() -> set DYING bit
__nf_ct_delete_from_lists
Even this scenario doesn't guarantee a crash:
cpu z still holds the table bucket lock(s) so y blocks:
wait for spinlock held by z
CONFIRMED is set but there is no
guarantee ct will be added to hash:
"chaintoolong" or "clash resolution"
logic both skip the insert step.
reply hnnode.pprev still stores the
hash value.
unlocks spinlock
return NF_DROP
<unblocks, then
crashes on hlist_nulls_del_rcu pprev>
In case CPU z does insert the entry into the hashtable, cpu y will unlink
E again right away but no crash occurs.
Without 'cpu y' race, 'garbage' hlist is of no consequence:
ct refcnt remains at 1, eventually skb will be free'd and E gets
destroyed via: nf_conntrack_put -> nf_conntrack_destroy -> nf_ct_destroy.
To resolve this, move the IPS_CONFIRMED assignment after the table
insertion but before the unlock.
Pablo points out that the confirm-bit-store could be reordered to happen
before hlist add resp. the timeout fixup, so switch to set_bit and
before_atomic memory barrier to prevent this.
It doesn't matter if other CPUs can observe a newly inserted entry right
before the CONFIRMED bit was set:
Such event cannot be distinguished from above "E is the old incarnation"
case: the entry will be skipped.
Also change nf_ct_should_gc() to first check the confirmed bit.
The gc sequence is:
1. Check if entry has expired, if not skip to next entry
2. Obtain a reference to the expired entry.
3. Call nf_ct_should_gc() to double-check step 1.
nf_ct_should_gc() is thus called only for entries that already failed an
expiry check. After this patch, once the confirmed bit check pas
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28