CVE-2025-21756

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Source
https://nvd.nist.gov/vuln/detail/CVE-2025-21756
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21756.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-21756
Aliases
Downstream
Related
Published
2025-02-27T02:18:11Z
Modified
2025-10-22T10:44:06.463316Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
vsock: Keep the binding until socket destruction
Details

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 _vsockbind+0x62e/0x730 Read of size 4 at addr ffff88816b46a74c by task a.out/2057 dumpstacklvl+0x68/0x90 printreport+0x174/0x4f6 kasanreport+0xb9/0x190 _vsockbind+0x62e/0x730 vsockbind+0x97/0xe0 _sysbind+0x154/0x1f0 _x64sysbind+0x6e/0xb0 dosyscall64+0x93/0x1b0 entrySYSCALL64afterhwframe+0x76/0x7e

Allocated by task 2057: kasansavestack+0x1e/0x40 kasansavetrack+0x10/0x30 _kasanslaballoc+0x85/0x90 kmemcacheallocnoprof+0x131/0x450 skprotalloc+0x5b/0x220 skalloc+0x2c/0x870 _vsockcreate.constprop.0+0x2e/0xb60 vsockcreate+0xe4/0x420 _sockcreate+0x241/0x650 _syssocket+0xf2/0x1a0 _x64syssocket+0x6e/0xb0 dosyscall64+0x93/0x1b0 entrySYSCALL64after_hwframe+0x76/0x7e

Freed by task 2057: kasansavestack+0x1e/0x40 kasansavetrack+0x10/0x30 kasansavefreeinfo+0x37/0x60 _kasanslabfree+0x4b/0x70 kmemcachefree+0x1a1/0x590 _skdestruct+0x388/0x5a0 _vsockbind+0x5e1/0x730 vsockbind+0x97/0xe0 _sysbind+0x154/0x1f0 _x64sysbind+0x6e/0xb0 dosyscall64+0x93/0x1b0 entrySYSCALL64afterhwframe+0x76/0x7e

refcountt: addition on 0; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcountwarnsaturate+0xce/0x150 RIP: 0010:refcountwarnsaturate+0xce/0x150 _vsockbind+0x66d/0x730 vsockbind+0x97/0xe0 _sysbind+0x154/0x1f0 _x64sysbind+0x6e/0xb0 dosyscall64+0x93/0x1b0 entrySYSCALL64after_hwframe+0x76/0x7e

refcountt: underflow; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcountwarnsaturate+0xee/0x150 RIP: 0010:refcountwarnsaturate+0xee/0x150 vsockremovebound+0x187/0x1e0 _vsockrelease+0x383/0x4a0 vsockrelease+0x90/0x120 _sockrelease+0xa3/0x250 sockclose+0x14/0x20 _fput+0x359/0xa80 taskworkrun+0x107/0x1d0 doexit+0x847/0x2560 dogroupexit+0xb8/0x250 _x64sysexitgroup+0x3a/0x50 x64syscall+0xfec/0x14f0 dosyscall64+0x93/0x1b0 entrySYSCALL64after_hwframe+0x76/0x7e

References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
e7754d564579a5db9c5c9f74228df5d6dd6f1173
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
e48fcb403c2d0e574c19683f09399ab4cf67809c
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
42b33381e5e1f2b967dc4fb4221ddb9aaf10d197
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
3f43540166128951cc1be7ab1ce6b7f05c670d8b
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
645ce25aa0e67895b11d89f27bb86c9d444c40f8
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
b1afd40321f1c243cffbcf40ea7ca41aca87fa5e
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c0cfa2d8a788fcf45df5bf4070ab2474c88d543a
Fixed
fcdd2242c0231032fc84e1404315c245ae56322a

Affected versions

v5.*

v5.10
v5.10-rc1
v5.10-rc2
v5.10-rc3
v5.10-rc4
v5.10-rc5
v5.10-rc6
v5.10-rc7
v5.10.1
v5.10.10
v5.10.100
v5.10.101
v5.10.102
v5.10.103
v5.10.104
v5.10.105
v5.10.106
v5.10.107
v5.10.108
v5.10.109
v5.10.11
v5.10.110
v5.10.111
v5.10.112
v5.10.113
v5.10.114
v5.10.115
v5.10.116
v5.10.117
v5.10.118
v5.10.119
v5.10.12
v5.10.120
v5.10.121
v5.10.122
v5.10.123
v5.10.124
v5.10.125
v5.10.126
v5.10.127
v5.10.128
v5.10.129
v5.10.13
v5.10.130
v5.10.131
v5.10.132
v5.10.133
v5.10.134
v5.10.135
v5.10.136
v5.10.137
v5.10.138
v5.10.139
v5.10.14
v5.10.140
v5.10.141
v5.10.142
v5.10.143
v5.10.144
v5.10.145
v5.10.146
v5.10.147
v5.10.148
v5.10.149
v5.10.15
v5.10.150
v5.10.151
v5.10.152
v5.10.153
v5.10.154
v5.10.155
v5.10.156
v5.10.157
v5.10.158
v5.10.159
v5.10.16
v5.10.160
v5.10.161
v5.10.162
v5.10.163
v5.10.164
v5.10.165
v5.10.166
v5.10.167
v5.10.168
v5.10.169
v5.10.17
v5.10.170
v5.10.171
v5.10.172
v5.10.173
v5.10.174
v5.10.175
v5.10.176
v5.10.177
v5.10.178
v5.10.179
v5.10.18
v5.10.180
v5.10.181
v5.10.182
v5.10.183
v5.10.184
v5.10.185
v5.10.186
v5.10.187
v5.10.188
v5.10.189
v5.10.19
v5.10.190
v5.10.191
v5.10.192
v5.10.193
v5.10.194
v5.10.195
v5.10.196
v5.10.197
v5.10.198
v5.10.199
v5.10.2
v5.10.20
v5.10.200
v5.10.201
v5.10.202
v5.10.203
v5.10.204
v5.10.205
v5.10.206
v5.10.207
v5.10.208
v5.10.209
v5.10.21
v5.10.210
v5.10.211
v5.10.212
v5.10.213
v5.10.214
v5.10.215
v5.10.216
v5.10.217
v5.10.218
v5.10.219
v5.10.22
v5.10.220
v5.10.221
v5.10.222
v5.10.223
v5.10.224
v5.10.225
v5.10.226
v5.10.227
v5.10.228
v5.10.229
v5.10.23
v5.10.230
v5.10.231
v5.10.232
v5.10.233
v5.10.234
v5.10.24
v5.10.25
v5.10.26
v5.10.27
v5.10.28
v5.10.29
v5.10.3
v5.10.30
v5.10.31
v5.10.32
v5.10.33
v5.10.34
v5.10.35
v5.10.36
v5.10.37
v5.10.38
v5.10.39
v5.10.4
v5.10.40
v5.10.41
v5.10.42
v5.10.43
v5.10.44
v5.10.45
v5.10.46
v5.10.47
v5.10.48
v5.10.49
v5.10.5
v5.10.50
v5.10.51
v5.10.52
v5.10.53
v5.10.54
v5.10.55
v5.10.56
v5.10.57
v5.10.58
v5.10.59
v5.10.6
v5.10.60
v5.10.61
v5.10.62
v5.10.63
v5.10.64
v5.10.65
v5.10.66
v5.10.67
v5.10.68
v5.10.69
v5.10.7
v5.10.70
v5.10.71
v5.10.72
v5.10.73
v5.10.74
v5.10.75
v5.10.76
v5.10.77
v5.10.78
v5.10.79
v5.10.8
v5.10.80
v5.10.81
v5.10.82
v5.10.83
v5.10.84
v5.10.85
v5.10.86
v5.10.87
v5.10.88
v5.10.89
v5.10.9
v5.10.90
v5.10.91
v5.10.92
v5.10.93
v5.10.94
v5.10.95
v5.10.96
v5.10.97
v5.10.98
v5.10.99
v5.11
v5.11-rc1
v5.11-rc2
v5.11-rc3
v5.11-rc4
v5.11-rc5
v5.11-rc6
v5.11-rc7
v5.12
v5.12-rc1
v5.12-rc1-dontuse
v5.12-rc2
v5.12-rc3
v5.12-rc4
v5.12-rc5
v5.12-rc6
v5.12-rc7
v5.12-rc8
v5.13
v5.13-rc1
v5.13-rc2
v5.13-rc3
v5.13-rc4
v5.13-rc5
v5.13-rc6
v5.13-rc7
v5.14
v5.14-rc1
v5.14-rc2
v5.14-rc3
v5.14-rc4
v5.14-rc5
v5.14-rc6
v5.14-rc7
v5.15
v5.15-rc1
v5.15-rc2
v5.15-rc3
v5.15-rc4
v5.15-rc5
v5.15-rc6
v5.15-rc7
v5.15.1
v5.15.10
v5.15.100
v5.15.101
v5.15.102
v5.15.103
v5.15.104
v5.15.105
v5.15.106
v5.15.107
v5.15.108
v5.15.109
v5.15.11
v5.15.110
v5.15.111
v5.15.112
v5.15.113
v5.15.114
v5.15.115
v5.15.116
v5.15.117
v5.15.118
v5.15.119
v5.15.12
v5.15.120
v5.15.121
v5.15.122
v5.15.123
v5.15.124
v5.15.125
v5.15.126
v5.15.127
v5.15.128
v5.15.129
v5.15.13
v5.15.130
v5.15.131
v5.15.132
v5.15.133
v5.15.134
v5.15.135
v5.15.136
v5.15.137
v5.15.138
v5.15.139
v5.15.14
v5.15.140
v5.15.141
v5.15.142
v5.15.143
v5.15.144
v5.15.145
v5.15.146
v5.15.147
v5.15.148
v5.15.149
v5.15.15
v5.15.150
v5.15.151
v5.15.152
v5.15.153
v5.15.154
v5.15.155
v5.15.156
v5.15.157
v5.15.158
v5.15.159
v5.15.16
v5.15.160
v5.15.161
v5.15.162
v5.15.163
v5.15.164
v5.15.165
v5.15.166
v5.15.167
v5.15.168
v5.15.169
v5.15.17
v5.15.170
v5.15.171
v5.15.172
v5.15.173
v5.15.174
v5.15.175
v5.15.176
v5.15.177
v5.15.178
v5.15.18
v5.15.19
v5.15.2
v5.15.20
v5.15.21
v5.15.22
v5.15.23
v5.15.24
v5.15.25
v5.15.26
v5.15.27
v5.15.28
v5.15.29
v5.15.3
v5.15.30
v5.15.31
v5.15.32
v5.15.33
v5.15.34
v5.15.35
v5.15.36
v5.15.37
v5.15.38
v5.15.39
v5.15.4
v5.15.40
v5.15.41
v5.15.42
v5.15.43
v5.15.44
v5.15.45
v5.15.46
v5.15.47
v5.15.48
v5.15.49
v5.15.5
v5.15.50
v5.15.51
v5.15.52
v5.15.53
v5.15.54
v5.15.55
v5.15.56
v5.15.57
v5.15.58
v5.15.59
v5.15.6
v5.15.60
v5.15.61
v5.15.62
v5.15.63
v5.15.64
v5.15.65
v5.15.66
v5.15.67
v5.15.68
v5.15.69
v5.15.7
v5.15.70
v5.15.71
v5.15.72
v5.15.73
v5.15.74
v5.15.75
v5.15.76
v5.15.77
v5.15.78
v5.15.79
v5.15.8
v5.15.80
v5.15.81
v5.15.82
v5.15.83
v5.15.84
v5.15.85
v5.15.86
v5.15.87
v5.15.88
v5.15.89
v5.15.9
v5.15.90
v5.15.91
v5.15.92
v5.15.93
v5.15.94
v5.15.95
v5.15.96
v5.15.97
v5.15.98
v5.15.99
v5.16
v5.16-rc1
v5.16-rc2
v5.16-rc3
v5.16-rc4
v5.16-rc5
v5.16-rc6
v5.16-rc7
v5.16-rc8
v5.17
v5.17-rc1
v5.17-rc2
v5.17-rc3
v5.17-rc4
v5.17-rc5
v5.17-rc6
v5.17-rc7
v5.17-rc8
v5.18
v5.18-rc1
v5.18-rc2
v5.18-rc3
v5.18-rc4
v5.18-rc5
v5.18-rc6
v5.18-rc7
v5.19
v5.19-rc1
v5.19-rc2
v5.19-rc3
v5.19-rc4
v5.19-rc5
v5.19-rc6
v5.19-rc7
v5.19-rc8
v5.4
v5.4-rc7
v5.4-rc8
v5.5
v5.5-rc1
v5.5-rc2
v5.5-rc3
v5.5-rc4
v5.5-rc5
v5.5-rc6
v5.5-rc7
v5.6
v5.6-rc1
v5.6-rc2
v5.6-rc3
v5.6-rc4
v5.6-rc5
v5.6-rc6
v5.6-rc7
v5.7
v5.7-rc1
v5.7-rc2
v5.7-rc3
v5.7-rc4
v5.7-rc5
v5.7-rc6
v5.7-rc7
v5.8
v5.8-rc1
v5.8-rc2
v5.8-rc3
v5.8-rc4
v5.8-rc5
v5.8-rc6
v5.8-rc7
v5.9
v5.9-rc1
v5.9-rc2
v5.9-rc3
v5.9-rc4
v5.9-rc5
v5.9-rc6
v5.9-rc7
v5.9-rc8

v6.*

v6.0
v6.0-rc1
v6.0-rc2
v6.0-rc3
v6.0-rc4
v6.0-rc5
v6.0-rc6
v6.0-rc7
v6.1
v6.1-rc1
v6.1-rc2
v6.1-rc3
v6.1-rc4
v6.1-rc5
v6.1-rc6
v6.1-rc7
v6.1-rc8
v6.1.1
v6.1.10
v6.1.100
v6.1.101
v6.1.102
v6.1.103
v6.1.104
v6.1.105
v6.1.106
v6.1.107
v6.1.108
v6.1.109
v6.1.11
v6.1.110
v6.1.111
v6.1.112
v6.1.113
v6.1.114
v6.1.115
v6.1.116
v6.1.117
v6.1.118
v6.1.119
v6.1.12
v6.1.120
v6.1.121
v6.1.122
v6.1.123
v6.1.124
v6.1.125
v6.1.126
v6.1.127
v6.1.128
v6.1.129
v6.1.13
v6.1.130
v6.1.14
v6.1.15
v6.1.16
v6.1.17
v6.1.18
v6.1.19
v6.1.2
v6.1.20
v6.1.21
v6.1.22
v6.1.23
v6.1.24
v6.1.25
v6.1.26
v6.1.27
v6.1.28
v6.1.29
v6.1.3
v6.1.30
v6.1.31
v6.1.32
v6.1.33
v6.1.34
v6.1.35
v6.1.36
v6.1.37
v6.1.38
v6.1.39
v6.1.4
v6.1.40
v6.1.41
v6.1.42
v6.1.43
v6.1.44
v6.1.45
v6.1.46
v6.1.47
v6.1.48
v6.1.49
v6.1.5
v6.1.50
v6.1.51
v6.1.52
v6.1.53
v6.1.54
v6.1.55
v6.1.56
v6.1.57
v6.1.58
v6.1.59
v6.1.6
v6.1.60
v6.1.61
v6.1.62
v6.1.63
v6.1.64
v6.1.65
v6.1.66
v6.1.67
v6.1.68
v6.1.69
v6.1.7
v6.1.70
v6.1.71
v6.1.72
v6.1.73
v6.1.74
v6.1.75
v6.1.76
v6.1.77
v6.1.78
v6.1.79
v6.1.8
v6.1.80
v6.1.81
v6.1.82
v6.1.83
v6.1.84
v6.1.85
v6.1.86
v6.1.87
v6.1.88
v6.1.89
v6.1.9
v6.1.90
v6.1.91
v6.1.92
v6.1.93
v6.1.94
v6.1.95
v6.1.96
v6.1.97
v6.1.98
v6.1.99
v6.10
v6.10-rc1
v6.10-rc2
v6.10-rc3
v6.10-rc4
v6.10-rc5
v6.10-rc6
v6.10-rc7
v6.11
v6.11-rc1
v6.11-rc2
v6.11-rc3
v6.11-rc4
v6.11-rc5
v6.11-rc6
v6.11-rc7
v6.12
v6.12-rc1
v6.12-rc2
v6.12-rc3
v6.12-rc4
v6.12-rc5
v6.12-rc6
v6.12-rc7
v6.12.1
v6.12.10
v6.12.11
v6.12.12
v6.12.13
v6.12.14
v6.12.15
v6.12.2
v6.12.3
v6.12.4
v6.12.5
v6.12.6
v6.12.7
v6.12.8
v6.12.9
v6.13
v6.13-rc1
v6.13-rc2
v6.13-rc3
v6.13-rc4
v6.13-rc5
v6.13-rc6
v6.13-rc7
v6.13.1
v6.13.2
v6.13.3
v6.2
v6.2-rc1
v6.2-rc2
v6.2-rc3
v6.2-rc4
v6.2-rc5
v6.2-rc6
v6.2-rc7
v6.2-rc8
v6.3
v6.3-rc1
v6.3-rc2
v6.3-rc3
v6.3-rc4
v6.3-rc5
v6.3-rc6
v6.3-rc7
v6.4
v6.4-rc1
v6.4-rc2
v6.4-rc3
v6.4-rc4
v6.4-rc5
v6.4-rc6
v6.4-rc7
v6.5
v6.5-rc1
v6.5-rc2
v6.5-rc3
v6.5-rc4
v6.5-rc5
v6.5-rc6
v6.5-rc7
v6.6
v6.6-rc1
v6.6-rc2
v6.6-rc3
v6.6-rc4
v6.6-rc5
v6.6-rc6
v6.6-rc7
v6.6.1
v6.6.10
v6.6.11
v6.6.12
v6.6.13
v6.6.14
v6.6.15
v6.6.16
v6.6.17
v6.6.18
v6.6.19
v6.6.2
v6.6.20
v6.6.21
v6.6.22
v6.6.23
v6.6.24
v6.6.25
v6.6.26
v6.6.27
v6.6.28
v6.6.29
v6.6.3
v6.6.30
v6.6.31
v6.6.32
v6.6.33
v6.6.34
v6.6.35
v6.6.36
v6.6.37
v6.6.38
v6.6.39
v6.6.4
v6.6.40
v6.6.41
v6.6.42
v6.6.43
v6.6.44
v6.6.45
v6.6.46
v6.6.47
v6.6.48
v6.6.49
v6.6.5
v6.6.50
v6.6.51
v6.6.52
v6.6.53
v6.6.54
v6.6.55
v6.6.56
v6.6.57
v6.6.58
v6.6.59
v6.6.6
v6.6.60
v6.6.61
v6.6.62
v6.6.63
v6.6.64
v6.6.65
v6.6.66
v6.6.67
v6.6.68
v6.6.69
v6.6.7
v6.6.70
v6.6.71
v6.6.72
v6.6.73
v6.6.74
v6.6.75
v6.6.76
v6.6.77
v6.6.78
v6.6.8
v6.6.9
v6.7
v6.7-rc1
v6.7-rc2
v6.7-rc3
v6.7-rc4
v6.7-rc5
v6.7-rc6
v6.7-rc7
v6.7-rc8
v6.8
v6.8-rc1
v6.8-rc2
v6.8-rc3
v6.8-rc4
v6.8-rc5
v6.8-rc6
v6.8-rc7
v6.9
v6.9-rc1
v6.9-rc2
v6.9-rc3
v6.9-rc4
v6.9-rc5
v6.9-rc6
v6.9-rc7

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.5.0
Fixed
5.10.235
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.179
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.131
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.79
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.16
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.13.4