CVE-2025-21945

ksmbd: fix use-after-free in smb2_lock

8.8 HighFix available

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb2_lock

If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.53%Up 0.5 points since Apr 2, 2025

What each source reports

CVE List Score used 8.8

ksmbd: fix use-after-free in smb2_lock

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb2_lock

If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Record: CVE-2025-21945
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-416
Updated: 2026-11-02

EUVDEUVD-2025-9376 8.8

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb2_lock

If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Record: EUVD-2025-9376
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-5g8p-x9mm-c9vr 7.8

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in...

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb2_lock

If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Record: GHSA-5g8p-x9mm-c9vr
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-416
Updated: 2026-11-02

NVD 8.8

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb2_lock

If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Record: CVE-2025-21945
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-416
Updated: 2026-11-02

OSVBELL-CVE-2025-21945 7.8

Record: BELL-CVE-2025-21945
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSV 8.8

ksmbd: fix use-after-free in smb2_lock

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb2_lock

If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Record: CVE-2025-21945
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

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OSVDEBIAN-CVE-2025-21945 7.8

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb2_lock If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Record: DEBIAN-CVE-2025-21945
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVOESA-2025-2772 7.8

kernel security update

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

media: davinci: vpif: fix use-after-free on driver unbind

The driver allocates and registers two platform device structures during probe, but the devices were never deregistered on driver unbind.

This results in a use-after-free on driver unbind as the device structures were allocated using devres and would be freed by driver core when remove() returns.

Fix this by adding the missing deregistration calls to the remove() callback and failing probe on registration errors.

Note that the platform device structures must be freed using a proper release callback to avoid leaking associated resources like device names.(CVE-2021-47653)

In the Linux kernel, the following vulnerability has been resolved:

mmc: core: use sysfs_emit() instead of sprintf()

sprintf() (still used in the MMC core for the sysfs output) is vulnerable to the buffer overflow. Use the new-fangled sysfs_emit() instead.

Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool.(CVE-2022-49267)

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event

We should not access skb buffer data anymore after hci_recv_frame was called.

[ 39.634809] BUG: KASAN: use-after-free in btmtksdio_recv_event+0x1b0 [ 39.634855] Read of size 1 at addr ffffff80cf28a60d by task kworker [ 39.634962] Call trace: [ 39.634974] dump_backtrace+0x0/0x3b8 [ 39.634999] show_stack+0x20/0x2c [ 39.635016] dump_stack_lvl+0x60/0x78 [ 39.635040] print_address_description+0x70/0x2f0 [ 39.635062] kasan_report+0x154/0x194 [ 39.635079] __asan_report_load1_noabort+0x44/0x50 [ 39.635099] btmtksdio_recv_event+0x1b0/0x1c4 [ 39.635129] btmtksdio_txrx_work+0x6cc/0xac4 [ 39.635157] process_one_work+0x560/0xc5c [ 39.635177] worker_thread+0x7ec/0xcc0 [ 39.635195] kthread+0x2d0/0x3d0 [ 39.635215] ret_from_fork+0x10/0x20 [ 39.635247] Allocated by task 0: [ 39.635260] (stack is not available) [ 39.635281] Freed by task 2392: [ 39.635295] kasan_save_stack+0x38/0x68 [ 39.635319] kasan_set_track+0x28/0x3c [ 39.635338] kasan_set_free_info+0x28/0x4c [ 39.635357] ____kasan_slab_free+0x104/0x150 [ 39.635374] __kasan_slab_free+0x18/0x28 [ 39.635391] slab_free_freelist_hook+0x114/0x248 [ 39.635410] kfree+0xf8/0x2b4 [ 39.635427] skb_free_head+0x58/0x98 [ 39.635447] skb_release_data+0x2f4/0x410 [ 39.635464] skb_release_all+0x50/0x60 [ 39.635481] kfree_skb+0xc8/0x25c [ 39.635498] hci_event_packet+0x894/0xca4 [bluetooth] [ 39.635721] hci_rx_work+0x1c8/0x68c [bluetooth] [ 39.635925] process_one_work+0x560/0xc5c [ 39.635951] worker_thread+0x7ec/0xcc0 [ 39.635970] kthread+0x2d0/0x3d0 [ 39.635990] ret_from_fork+0x10/0x20 [ 39.636021] The buggy address belongs to the object at ffffff80cf28a600 which belongs to the cache kmalloc-512 of size 512 [ 39.636039] The buggy address is located 13 bytes inside of 512-byte region [ffffff80cf28a600, ffffff80cf28a800)(CVE-2022-49470)

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix use-after-free

Fix potential use-after-free in l2cap_le_command_rej.(CVE-2023-53305)

In the Linux kernel, the following vulnerability has been resolved:

ip6mr: Fix skb_under_panic in ip6mr_cache_report()

skbuff: skb_under_panic: text:ffffffff88771f69 len:56 put:-4 head:ffff88805f86a800 data:ffff887f5f86a850 tail:0x88 end:0x2c0 dev:pim6reg ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:192! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 2 PID: 22968 Comm: kworker/2:11 Not tainted 6.5.0-rc3-00044-g0a8db05b571a #236 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: ipv6_addrconf addrconf_dad_work RIP:…

Record: OESA-2025-2772
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVOESA-2025-2773 7.8

kernel security update

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

media: davinci: vpif: fix use-after-free on driver unbind

The driver allocates and registers two platform device structures during probe, but the devices were never deregistered on driver unbind.

This results in a use-after-free on driver unbind as the device structures were allocated using devres and would be freed by driver core when remove() returns.

Fix this by adding the missing deregistration calls to the remove() callback and failing probe on registration errors.

Note that the platform device structures must be freed using a proper release callback to avoid leaking associated resources like device names.(CVE-2021-47653)

In the Linux kernel, the following vulnerability has been resolved:

mmc: core: use sysfs_emit() instead of sprintf()

sprintf() (still used in the MMC core for the sysfs output) is vulnerable to the buffer overflow. Use the new-fangled sysfs_emit() instead.

Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool.(CVE-2022-49267)

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event

We should not access skb buffer data anymore after hci_recv_frame was called.

In the Linux kernel, the following vulnerability has been resolved:

scsi: ufs: core: Fix handling of lrbp->cmd

ufshcd_queuecommand() may be called two times in a row for a SCSI command before it is completed. Hence make the following changes:

In the functions that submit a command, do not check the old value of lrbp->cmd nor clear lrbp->cmd in error paths.
In ufshcd_release_scsi_cmd(), do not clear lrbp->cmd.

See also scsi_send_eh_cmnd().

This commit prevents that the following appears if a command times out:

WARNING: at drivers/ufs/core/ufshcd.c:2965 ufshcd_queuecommand+0x6f8/0x9a8 Call trace: ufshcd_queuecommand+0x6f8/0x9a8 scsi_send_eh_cmnd+0x2c0/0x960 scsi_eh_test_devices+0x100/0x314 scsi_eh_ready_devs+0xd90/0x114c …

Record: OESA-2025-2773
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVOESA-2025-2802 7.8

kernel security update

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

nfc: nci: Fix uninit-value in nci_rx_work

syzbot reported the following uninit-value access issue [1]

nci_rx_work() parses received packet from ndev->rx_q. It should be validated header size, payload size and total packet size before processing the packet. If an invalid packet is detected, it should be silently discarded.(CVE-2024-38381)

In the Linux kernel, the following vulnerability has been resolved:net: ti: icssg_prueth: Fix NULL pointer dereference in prueth_probe()In the prueth_probe() function, if one of the calls to emac_phy_connect()fails due to of_phy_connect() returning NULL, then the subsequent call tophy_attached_info() will dereference a NULL pointer.Check the return code of emac_phy_connect and fail cleanly if there is anerror.(CVE-2024-38584)

In the Linux kernel, the following vulnerability has been resolved:cpufreq: exit() callback is optionalThe exit() callback is optional and shouldn t be called without checkinga valid pointer first.Also, we must clear freq_table pointer even if the exit() callback isn tpresent.(CVE-2024-38615)

In the Linux kernel, the following vulnerability has been resolved:serial: max3100: Update uart_driver_registered on driver removalThe removal of the last MAX3100 device triggers the removal ofthe driver. However, code doesn t update the respective globalvariable and after insmod — rmmod — insmod cycle the kerneloopses: max3100 spi-PRP0001:01: max3100_probe: adding port 0 BUG: kernel NULL pointer dereference, address: 0000000000000408 ... RIP: 0010:serial_core_register_port+0xa0/0x840 ... max3100_probe+0x1b6/0x280 [max3100] spi_probe+0x8d/0xb0Update the actual state so next time UART driver will be registeredagain.Hugo also noticed, that the error path in the probe also affectedby having the variable set, and not cleared. Instead of clearing itmove the assignment after the successfull uart_register_driver() call.(CVE-2024-38633)

In the Linux kernel, the following vulnerability has been resolved:

enic: Validate length of nl attributes in enic_set_vf_port

enic_set_vf_port assumes that the nl attribute IFLA_PORT_PROFILE is of length PORT_PROFILE_MAX and that the nl attributes IFLA_PORT_INSTANCE_UUID, IFLA_PORT_HOST_UUID are of length PORT_UUID_MAX. These attributes are validated (in the function do_setlink in rtnetlink.c) using the nla_policy ifla_port_policy. The policy defines IFLA_PORT_PROFILE as NLA_STRING, IFLA_PORT_INSTANCE_UUID as NLA_BINARY and IFLA_PORT_HOST_UUID as NLA_STRING. That means that the length validation using the policy is for the max size of the attributes and not on exact size so the length of these attributes might be less than the sizes that enic_set_vf_port expects. This might cause an out of bands read access in the memcpys of the data of these attributes in enic_set_vf_port.(CVE-2024-38659)

In the Linux kernel, the following vulnerability has been resolved:riscv: prevent pt_regs corruption for secondary idle threadsTop of the kernel thread stack should be reserved for pt_regs. Howeverthis is not the case for the idle threads of the secondary boot harts.Their stacks overlap with their pt_regs, so both may get corrupted.Similar issue has been fixed for the primary hart, see c7cdd96eca28( riscv: prevent stack corruption by reserving task_pt_regs(p) early ).However that fix was not propagated to the secondary harts. The problemhas been noticed in some CPU hotplug tests with V enabled. The functionsmp_callin stored several registers on stack, corrupting top of pt_regsstructure including status field. As a result, kernel attempted to saveor restore inexistent V context.(CVE-2024-38667)

In the Linux kernel, the following vulnerability has been resolved:jfs: xattr: fix buffer overflow for invalid xattrWhen an xattr size is not what is expected, it is printed out to thekernel log in hex format as a…

Record: OESA-2025-2802
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVOESA-2025-2803 7.8

kernel security update

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint

Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints".

This series fixes null pointer dereference bugs that occur when using nilfs2 and two block-related tracepoints.

This patch (of 2):

It has been reported that when using "block:block_touch_buffer" tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a NULL pointer dereference, or a general protection fault when KASAN is enabled.

This happens because since the tracepoint was added in touch_buffer(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, the block_device structure is set after the function returns to the caller.

Here, touch_buffer() is used to mark the folio/page that owns the buffer head as accessed, but the common search helper for folio/page used by the caller function was optimized to mark the folio/page as accessed when it was reimplemented a long time ago, eliminating the need to call touch_buffer() here in the first place.

So this solves the issue by eliminating the touch_buffer() call itself.(CVE-2024-53131)

In the Linux kernel, the following vulnerability has been resolved:drm: adv7511: Fix use-after-free in adv7533_attach_dsi()The host_node pointer was assigned and freed in adv7533_parse_dt(), andlater, adv7533_attach_dsi() uses the same. Fix this use-after-free issueby dropping of_node_put() in adv7533_parse_dt() and calling of_node_put()in error path of probe() and also in the remove().(CVE-2024-57887)

In the Linux kernel, the following vulnerability has been resolved:ila: serialize calls to nf_register_net_hooks()syzbot found a race in ila_add_mapping() [1]commit 031ae72825ce ( ila: call nf_unregister_net_hooks() sooner )attempted to fix a similar issue.Looking at the syzbot repro, we have concurrent ILA_CMD_ADD commands.Add a mutex to make sure at most one thread is calling nf_register_net_hooks().[1] BUG: KASAN: slab-use-after-free in rht_key_hashfn include/linux/rhashtable.h:159 [inline] BUG: KASAN: slab-use-after-free in __rhashtable_lookup.constprop.0+0x426/0x550 include/linux/rhashtable.h:604Read of size 4 at addr ffff888028f40008 by task dhcpcd/5501CPU: 1 UID: 0 PID: 5501 Comm: dhcpcd Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024Call Trace: <IRQ> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 rht_key_hashfn include/linux/rhashtable.h:159 [inline] __rhashtable_lookup.constprop.0+0x426/0x550 include/linux/rhashtable.h:604 rhashtable_lookup include/linux/rhashtable.h:646 [inline] rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] ila_lookup_wildcards net/ipv6/ila/ila_xlat.c:127 [inline] ila_xlat_addr net/ipv6/ila/ila_xlat.c:652 [inline] ila_nf_input+0x1ee/0x620 net/ipv6/ila/ila_xlat.c:185 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0xa4/0x680 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1e0 net/core/dev.c:5672 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5785 process_backlog+0x443/0x15f0 net/core/dev.c:6117 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6883 napi_poll net/core/dev.c:6952 [inline] net_rx_action+0xa94/0x1010 net/core/dev.c:7074 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] …

Record: OESA-2025-2803
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVROOT-OS-UBUNTU-2204-CVE-2025-21945 7.8

CVE-2025-21945 in linux - Patched by Root

Root has patched CVE-2025-21945 in the linux package for Root:Ubuntu:22.04. Multiple fixed versions available.

Record: ROOT-OS-UBUNTU-2204-CVE-2025-21945
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-06

OSVROOT-OS-UBUNTU-2404-CVE-2025-21945 7.8

CVE-2025-21945 in linux - Patched by Root

Root has patched CVE-2025-21945 in the linux package for Root:Ubuntu:24.04. Multiple fixed versions available.

Record: ROOT-OS-UBUNTU-2404-CVE-2025-21945
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-06

OSVUBUNTU-CVE-2025-21945 8.7

Record: UBUNTU-CVE-2025-21945
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-11

OSVUSN-7605-1 No score

linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oracle, linux-raspi, linux-realtime vulnerabilities

It was discovered that the CIFS network file system implementation in the Linux kernel did not properly verify the target namespace when handling upcalls. An attacker could use this to expose sensitive information. (CVE-2025-2312)