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

vsock: Keep the binding until socket destruction

Preserve sockets bindings; this includes both resulting from an explicit
bind() and those implicitly bound through autobind during connect().

Prevents socket unbinding during a transport reassignment, which fixes a
use-after-free:

1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2)
2. transport->release() calls vsock_remove_bound() without checking if
sk was bound and moved to bound list (refcnt=1)
3. vsock_bind() assumes sk is in unbound list and before
__vsock_insert_bound(vsock_bound_sockets()) calls
__vsock_remove_bound() which does:
list_del_init(&vsk->bound_table); // nop
sock_put(&vsk->sk); // refcnt=0

BUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730
Read of size 4 at addr ffff88816b46a74c by task a.out/2057
dump_stack_lvl+0x68/0x90
print_report+0x174/0x4f6
kasan_report+0xb9/0x190
__vsock_bind+0x62e/0x730
vsock_bind+0x97/0xe0
__sys_bind+0x154/0x1f0
__x64_sys_bind+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e

Allocated by task 2057:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
__kasan_slab_alloc+0x85/0x90
kmem_cache_alloc_noprof+0x131/0x450
sk_prot_alloc+0x5b/0x220
sk_alloc+0x2c/0x870
__vsock_create.constprop.0+0x2e/0xb60
vsock_create+0xe4/0x420
__sock_create+0x241/0x650
__sys_socket+0xf2/0x1a0
__x64_sys_socket+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 2057:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kmem_cache_free+0x1a1/0x590
__sk_destruct+0x388/0x5a0
__vsock_bind+0x5e1/0x730
vsock_bind+0x97/0xe0
__sys_bind+0x154/0x1f0
__x64_sys_bind+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e

refcount_t: addition on 0; use-after-free.
WARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150
RIP: 0010:refcount_warn_saturate+0xce/0x150
__vsock_bind+0x66d/0x730
vsock_bind+0x97/0xe0
__sys_bind+0x154/0x1f0
__x64_sys_bind+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e

refcount_t: underflow; use-after-free.
WARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150
RIP: 0010:refcount_warn_saturate+0xee/0x150
vsock_remove_bound+0x187/0x1e0
__vsock_release+0x383/0x4a0
vsock_release+0x90/0x120
__sock_release+0xa3/0x250
sock_close+0x14/0x20
__fput+0x359/0xa80
task_work_run+0x107/0x1d0
do_exit+0x847/0x2560
do_group_exit+0xb8/0x250
__x64_sys_exit_group+0x3a/0x50
x64_sys_call+0xfec/0x14f0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4178-1 linux security update
Debian DLA Debian DLA DLA-4193-1 linux-6.1 security update
Debian DSA Debian DSA DSA-5900-1 linux security update
EUVD EUVD EUVD-2025-5169 In the Linux kernel, the following vulnerability has been resolved: vsock: Keep the binding until socket destruction Preserve sockets bindings; this includes both resulting from an explicit bind() and those implicitly bound through autobind during connect(). Prevents socket unbinding during a transport reassignment, which fixes a use-after-free: 1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2) 2. transport->release() calls vsock_remove_bound() without checking if sk was bound and moved to bound list (refcnt=1) 3. vsock_bind() assumes sk is in unbound list and before __vsock_insert_bound(vsock_bound_sockets()) calls __vsock_remove_bound() which does: list_del_init(&vsk->bound_table); // nop sock_put(&vsk->sk); // refcnt=0 BUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730 Read of size 4 at addr ffff88816b46a74c by task a.out/2057 dump_stack_lvl+0x68/0x90 print_report+0x174/0x4f6 kasan_report+0xb9/0x190 __vsock_bind+0x62e/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Allocated by task 2057: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x85/0x90 kmem_cache_alloc_noprof+0x131/0x450 sk_prot_alloc+0x5b/0x220 sk_alloc+0x2c/0x870 __vsock_create.constprop.0+0x2e/0xb60 vsock_create+0xe4/0x420 __sock_create+0x241/0x650 __sys_socket+0xf2/0x1a0 __x64_sys_socket+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 2057: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x60 __kasan_slab_free+0x4b/0x70 kmem_cache_free+0x1a1/0x590 __sk_destruct+0x388/0x5a0 __vsock_bind+0x5e1/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e refcount_t: addition on 0; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150 RIP: 0010:refcount_warn_saturate+0xce/0x150 __vsock_bind+0x66d/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e refcount_t: underflow; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150 RIP: 0010:refcount_warn_saturate+0xee/0x150 vsock_remove_bound+0x187/0x1e0 __vsock_release+0x383/0x4a0 vsock_release+0x90/0x120 __sock_release+0xa3/0x250 sock_close+0x14/0x20 __fput+0x359/0xa80 task_work_run+0x107/0x1d0 do_exit+0x847/0x2560 do_group_exit+0xb8/0x250 __x64_sys_exit_group+0x3a/0x50 x64_sys_call+0xfec/0x14f0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
Ubuntu USN Ubuntu USN USN-7445-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7448-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7449-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7449-2 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7450-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7451-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7452-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7453-1 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7455-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7455-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7455-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7455-4 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7455-5 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7459-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7459-2 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7460-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7468-1 Linux kernel (Azure, N-Series) vulnerabilities
Ubuntu USN Ubuntu USN USN-7475-1 Linux kernel (Xilinx ZynqMP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7523-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7524-1 Linux kernel (Raspberry Pi) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 03 Nov 2025 20:30:00 +0000


Thu, 14 Aug 2025 21:30:00 +0000

Type Values Removed Values Added
References

Tue, 03 Jun 2025 02:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:rhel_e4s:9.0
cpe:/o:redhat:rhel_eus:9.2
cpe:/o:redhat:rhel_eus:9.4

Mon, 26 May 2025 15:15:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10.0

Thu, 22 May 2025 03:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:8::nfv
cpe:/a:redhat:rhel_eus:9.4
cpe:/o:redhat:enterprise_linux:8

Tue, 20 May 2025 03:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:rhel_e4s:9.0
cpe:/a:redhat:rhel_e4s:9.0::nfv
cpe:/a:redhat:rhel_tus:8.4::nfv
cpe:/o:redhat:enterprise_linux:9
cpe:/o:redhat:rhel_aus:8.4
cpe:/o:redhat:rhel_e4s:8.4
cpe:/o:redhat:rhel_tus:8.4
Vendors & Products Redhat enterprise Linux

Fri, 16 May 2025 03:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Eus
Redhat rhel Tus
CPEs cpe:/a:redhat:rhel_eus:9.2
cpe:/a:redhat:rhel_eus:9.2::nfv
cpe:/o:redhat:rhel_aus:8.6
cpe:/o:redhat:rhel_e4s:8.6
cpe:/o:redhat:rhel_eus:8.8
cpe:/o:redhat:rhel_tus:8.6
Vendors & Products Redhat
Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Eus
Redhat rhel Tus

Thu, 01 May 2025 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 01 May 2025 02:45:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Moderate

threat_severity

Important


Wed, 30 Apr 2025 14:45:00 +0000

Type Values Removed Values Added
References

Mon, 24 Mar 2025 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Thu, 13 Mar 2025 12:30:00 +0000


Tue, 04 Mar 2025 03:45:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 28 Feb 2025 02:00:00 +0000


Thu, 27 Feb 2025 19:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Thu, 27 Feb 2025 02:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: vsock: Keep the binding until socket destruction Preserve sockets bindings; this includes both resulting from an explicit bind() and those implicitly bound through autobind during connect(). Prevents socket unbinding during a transport reassignment, which fixes a use-after-free: 1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2) 2. transport->release() calls vsock_remove_bound() without checking if sk was bound and moved to bound list (refcnt=1) 3. vsock_bind() assumes sk is in unbound list and before __vsock_insert_bound(vsock_bound_sockets()) calls __vsock_remove_bound() which does: list_del_init(&vsk->bound_table); // nop sock_put(&vsk->sk); // refcnt=0 BUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730 Read of size 4 at addr ffff88816b46a74c by task a.out/2057 dump_stack_lvl+0x68/0x90 print_report+0x174/0x4f6 kasan_report+0xb9/0x190 __vsock_bind+0x62e/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Allocated by task 2057: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x85/0x90 kmem_cache_alloc_noprof+0x131/0x450 sk_prot_alloc+0x5b/0x220 sk_alloc+0x2c/0x870 __vsock_create.constprop.0+0x2e/0xb60 vsock_create+0xe4/0x420 __sock_create+0x241/0x650 __sys_socket+0xf2/0x1a0 __x64_sys_socket+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 2057: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x60 __kasan_slab_free+0x4b/0x70 kmem_cache_free+0x1a1/0x590 __sk_destruct+0x388/0x5a0 __vsock_bind+0x5e1/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e refcount_t: addition on 0; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150 RIP: 0010:refcount_warn_saturate+0xce/0x150 __vsock_bind+0x66d/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e refcount_t: underflow; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150 RIP: 0010:refcount_warn_saturate+0xee/0x150 vsock_remove_bound+0x187/0x1e0 __vsock_release+0x383/0x4a0 vsock_release+0x90/0x120 __sock_release+0xa3/0x250 sock_close+0x14/0x20 __fput+0x359/0xa80 task_work_run+0x107/0x1d0 do_exit+0x847/0x2560 do_group_exit+0xb8/0x250 __x64_sys_exit_group+0x3a/0x50 x64_sys_call+0xfec/0x14f0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
Title vsock: Keep the binding until socket destruction
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-11-03T19:37:01.186Z

Reserved: 2024-12-29T08:45:45.760Z

Link: CVE-2025-21756

cve-icon Vulnrichment

Updated: 2025-11-03T19:37:01.186Z

cve-icon NVD

Status : Modified

Published: 2025-02-27T03:15:16.250

Modified: 2025-11-03T20:17:14.760

Link: CVE-2025-21756

cve-icon Redhat

Severity : Important

Publid Date: 2025-02-27T00:00:00Z

Links: CVE-2025-21756 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses