CVE-2025-21812 (GCVE-0-2025-21812)
Vulnerability from cvelistv5 – Published: 2025-02-27 20:01 – Updated: 2026-08-05 11:54
VLAI
EPSS
VEX
Title
ax25: rcu protect dev->ax25_ptr
Summary
In the Linux kernel, the following vulnerability has been resolved:
ax25: rcu protect dev->ax25_ptr
syzbot found a lockdep issue [1].
We should remove ax25 RTNL dependency in ax25_setsockopt()
This should also fix a variety of possible UAF in ax25.
[1]
WARNING: possible circular locking dependency detected
6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted
------------------------------------------------------
syz.5.1818/12806 is trying to acquire lock:
ffffffff8fcb3988 (rtnl_mutex){+.+.}-{4:4}, at: ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680
but task is already holding lock:
ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]
ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_AX25){+.+.}-{0:0}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
lock_sock_nested+0x48/0x100 net/core/sock.c:3642
lock_sock include/net/sock.h:1618 [inline]
ax25_kill_by_device net/ax25/af_ax25.c:101 [inline]
ax25_device_event+0x24d/0x580 net/ax25/af_ax25.c:146
notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
__dev_notify_flags+0x207/0x400
dev_change_flags+0xf0/0x1a0 net/core/dev.c:9026
dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:563
dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:820
sock_do_ioctl+0x240/0x460 net/socket.c:1234
sock_ioctl+0x626/0x8e0 net/socket.c:1339
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (rtnl_mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680
do_sock_setsockopt+0x3af/0x720 net/socket.c:2324
__sys_setsockopt net/socket.c:2349 [inline]
__do_sys_setsockopt net/socket.c:2355 [inline]
__se_sys_setsockopt net/socket.c:2352 [inline]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_AX25);
lock(rtnl_mutex);
lock(sk_lock-AF_AX25);
lock(rtnl_mutex);
*** DEADLOCK ***
1 lock held by syz.5.1818/12806:
#0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]
#0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574
stack backtrace:
CPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/lockin
---truncated---
Severity
7.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-03-04 18:00 UTC
CWE
- CWE-416 - Use After Free
Assigner
References
6 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
c433570458e49bccea5c551df628d058b3526289 , < 2802ed4ced27ebd474828fc67ffd7d66f11e3605
(git)
Affected: c433570458e49bccea5c551df628d058b3526289 , < 7705d8a7f2c26c80973c81093db07c6022b2b30e (git) Affected: c433570458e49bccea5c551df628d058b3526289 , < 8937f5e38a218531dce2a89fae60e3adcc2311e1 (git) Affected: c433570458e49bccea5c551df628d058b3526289 , < c2531db6de3c95551be58878f859c6a053b7eb2e (git) Affected: c433570458e49bccea5c551df628d058b3526289 , < 95fc45d1dea8e1253f8ec58abc5befb71553d666 (git) Affected: 7f93d703e276311dd289c9a520ce9e8c8fa2858c (git) Affected: c0e93a6d36135d5082cb3af8352f5b69c9f58d6e (git) Affected: c39b8fd4997bf99503b8e48d8cb0eedb1d9a54f0 (git) Affected: 26a5adc8eb26d170058645c3cccd4d19165bec16 (git) Affected: 3e881d8764ed9b04ae3e5c3e5d132acb75ef91ba (git) Affected: 77768c96dcf860c43b970b87b2a09229f84ea560 (git) Affected: 3.18.132 , < 3.19 (semver) Affected: 4.4.170 , < 4.5 (semver) Affected: 4.9.149 , < 4.10 (semver) Affected: 4.14.92 , < 4.15 (semver) Affected: 4.19.14 , < 4.20 (semver) Affected: 4.20.1 , < 4.21 (semver) |
guessed | |
| Linux | Linux |
Affected:
5.0
Unaffected: 0 , < 5.0 (semver) Unaffected: 6.1.129 , ≤ 6.1.* (semver) Unaffected: 6.6.76 , ≤ 6.6.* (semver) Unaffected: 6.12.13 , ≤ 6.12.* (semver) Unaffected: 6.13.2 , ≤ 6.13.* (semver) Unaffected: 6.14 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
},
{
"other": {
"content": {
"id": "CVE-2025-21812",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-03-04T18:00:00.916644Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-416",
"description": "CWE-416 Use After Free",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2025-03-04T18:07:17.248Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
},
{
"providerMetadata": {
"dateUpdated": "2025-11-03T20:59:48.635Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"
}
],
"title": "CVE Program Container"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/netdevice.h",
"include/net/ax25.h",
"net/ax25/af_ax25.c",
"net/ax25/ax25_dev.c",
"net/ax25/ax25_ip.c",
"net/ax25/ax25_out.c",
"net/ax25/ax25_route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2802ed4ced27ebd474828fc67ffd7d66f11e3605",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "7705d8a7f2c26c80973c81093db07c6022b2b30e",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "8937f5e38a218531dce2a89fae60e3adcc2311e1",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "c2531db6de3c95551be58878f859c6a053b7eb2e",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "95fc45d1dea8e1253f8ec58abc5befb71553d666",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"status": "affected",
"version": "7f93d703e276311dd289c9a520ce9e8c8fa2858c",
"versionType": "git"
},
{
"status": "affected",
"version": "c0e93a6d36135d5082cb3af8352f5b69c9f58d6e",
"versionType": "git"
},
{
"status": "affected",
"version": "c39b8fd4997bf99503b8e48d8cb0eedb1d9a54f0",
"versionType": "git"
},
{
"status": "affected",
"version": "26a5adc8eb26d170058645c3cccd4d19165bec16",
"versionType": "git"
},
{
"status": "affected",
"version": "3e881d8764ed9b04ae3e5c3e5d132acb75ef91ba",
"versionType": "git"
},
{
"status": "affected",
"version": "77768c96dcf860c43b970b87b2a09229f84ea560",
"versionType": "git"
},
{
"lessThan": "3.19",
"status": "affected",
"version": "3.18.132",
"versionType": "semver"
},
{
"lessThan": "4.5",
"status": "affected",
"version": "4.4.170",
"versionType": "semver"
},
{
"lessThan": "4.10",
"status": "affected",
"version": "4.9.149",
"versionType": "semver"
},
{
"lessThan": "4.15",
"status": "affected",
"version": "4.14.92",
"versionType": "semver"
},
{
"lessThan": "4.20",
"status": "affected",
"version": "4.19.14",
"versionType": "semver"
},
{
"lessThan": "4.21",
"status": "affected",
"version": "4.20.1",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/linux/netdevice.h",
"include/net/ax25.h",
"net/ax25/af_ax25.c",
"net/ax25/ax25_dev.c",
"net/ax25/ax25_ip.c",
"net/ax25/ax25_out.c",
"net/ax25/ax25_route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.0"
},
{
"lessThan": "5.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.129",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.76",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.13.*",
"status": "unaffected",
"version": "6.13.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.14",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.129",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.76",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.13",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.13.2",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.14",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "3.18.132",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.4.170",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.9.149",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.14.92",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.19.14",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.20.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nax25: rcu protect dev-\u003eax25_ptr\n\nsyzbot found a lockdep issue [1].\n\nWe should remove ax25 RTNL dependency in ax25_setsockopt()\n\nThis should also fix a variety of possible UAF in ax25.\n\n[1]\n\nWARNING: possible circular locking dependency detected\n6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted\n------------------------------------------------------\nsyz.5.1818/12806 is trying to acquire lock:\n ffffffff8fcb3988 (rtnl_mutex){+.+.}-{4:4}, at: ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680\n\nbut task is already holding lock:\n ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]\n ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-\u003e #1 (sk_lock-AF_AX25){+.+.}-{0:0}:\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849\n lock_sock_nested+0x48/0x100 net/core/sock.c:3642\n lock_sock include/net/sock.h:1618 [inline]\n ax25_kill_by_device net/ax25/af_ax25.c:101 [inline]\n ax25_device_event+0x24d/0x580 net/ax25/af_ax25.c:146\n notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85\n __dev_notify_flags+0x207/0x400\n dev_change_flags+0xf0/0x1a0 net/core/dev.c:9026\n dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:563\n dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:820\n sock_do_ioctl+0x240/0x460 net/socket.c:1234\n sock_ioctl+0x626/0x8e0 net/socket.c:1339\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:906 [inline]\n __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n-\u003e #0 (rtnl_mutex){+.+.}-{4:4}:\n check_prev_add kernel/locking/lockdep.c:3161 [inline]\n check_prevs_add kernel/locking/lockdep.c:3280 [inline]\n validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904\n __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849\n __mutex_lock_common kernel/locking/mutex.c:585 [inline]\n __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735\n ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680\n do_sock_setsockopt+0x3af/0x720 net/socket.c:2324\n __sys_setsockopt net/socket.c:2349 [inline]\n __do_sys_setsockopt net/socket.c:2355 [inline]\n __se_sys_setsockopt net/socket.c:2352 [inline]\n __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nother info that might help us debug this:\n\n Possible unsafe locking scenario:\n\n CPU0 CPU1\n ---- ----\n lock(sk_lock-AF_AX25);\n lock(rtnl_mutex);\n lock(sk_lock-AF_AX25);\n lock(rtnl_mutex);\n\n *** DEADLOCK ***\n\n1 lock held by syz.5.1818/12806:\n #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]\n #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574\n\nstack backtrace:\nCPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120\n print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074\n check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206\n check_prev_add kernel/locking/lockdep.c:3161 [inline]\n check_prevs_add kernel/lockin\n---truncated---"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The controllable attack path is an AF_AX25 socket driven by local syscalls (setsockopt SO_BINDTODEVICE, connect/sendmsg autobind, close), which is what both frees the ax25_dev and re-dereferences the dangling dev-\u003eax25_ptr. Although received AX.25 frames also read dev-\u003eax25_ptr in ax25_rcv(), an adjacent radio/L2 peer cannot itself cause the free, so the attacker must be local.\nAC:L - No race needs to be won: SO_BINDTODEVICE stores ax25-\u003eax25_dev without a reference while ax25_release() drops one, so a single setsockopt+close deterministically drives the refcount to zero and kfree()s the object still published in dev-\u003eax25_ptr. The pure device-down race variant is also attacker-driven by spinning setsockopt/connect in a loop.\nPR:L - ax25_create() imposes no capability check for SOCK_DGRAM/SOCK_SEQPACKET, and the AF_AX25 module autoloads via the net-pf-3 alias, so any unprivileged local user in the init namespace can reach every vulnerable path. Root is only needed for the one-time deployment setup of the AX.25 port, not by the attacker.\nUI:N - The entire sequence is performed by the attacker\u0027s own process through socket(), setsockopt(), connect()/sendmsg() and close(); no victim action is involved.\nS:U - The freed ax25_dev and the corrupted kernel heap are entirely within the kernel\u0027s own security authority, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - After the free, ax25_fillin_cb() copies bytes from the reclaimed slab object into the socket\u0027s t1/t2/t3/n2/paclen/window/backoff fields, which userspace reads back with getsockopt() \u2014 a direct kernel heap disclosure \u2014 and the general UAF read of ax25_dev-\u003edev/-\u003eforward enables broader information leakage.\nI:H - The dangling pointer yields repeated refcount_dec() and stores to ax25_dev-\u003eforward and -\u003edevice_up into memory that has been reallocated for other kernel objects, giving a controlled decrement/write primitive on a groomed heap that is exploitable for privilege escalation.\nA:H - Dereferencing and freeing the already-freed ax25_dev reliably produces a kernel oops/panic (and netdev refcount underflow), and the same commit fixes a genuine sk_lock-AF_AX25 versus rtnl_mutex ABBA deadlock that permanently wedges the rtnl mutex and with it the entire networking stack."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T11:54:40.014Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/2802ed4ced27ebd474828fc67ffd7d66f11e3605"
},
{
"url": "https://git.kernel.org/stable/c/7705d8a7f2c26c80973c81093db07c6022b2b30e"
},
{
"url": "https://git.kernel.org/stable/c/8937f5e38a218531dce2a89fae60e3adcc2311e1"
},
{
"url": "https://git.kernel.org/stable/c/c2531db6de3c95551be58878f859c6a053b7eb2e"
},
{
"url": "https://git.kernel.org/stable/c/95fc45d1dea8e1253f8ec58abc5befb71553d666"
}
],
"title": "ax25: rcu protect dev-\u003eax25_ptr",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-21812",
"datePublished": "2025-02-27T20:01:02.837Z",
"dateReserved": "2024-12-29T08:45:45.774Z",
"dateUpdated": "2026-08-05T11:54:40.014Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2025-21812",
"date": "2026-09-18",
"epss": "0.00227",
"percentile": "0.1374"
},
"microsoft_vex": {
"current_release_date": "2026-02-18T15:07:00.000Z",
"cve": "CVE-2025-21812",
"id": "msrc_CVE-2025-21812",
"initial_release_date": "2025-02-02T00:00:00.000Z",
"product_status:known_not_affected": "2",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "ax25: rcu protect dev-\u003eax25_ptr",
"url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-21812.json",
"version": "2"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/netdevice.h",
"include/net/ax25.h",
"net/ax25/af_ax25.c",
"net/ax25/ax25_dev.c",
"net/ax25/ax25_ip.c",
"net/ax25/ax25_out.c",
"net/ax25/ax25_route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2802ed4ced27ebd474828fc67ffd7d66f11e3605",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "7705d8a7f2c26c80973c81093db07c6022b2b30e",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "8937f5e38a218531dce2a89fae60e3adcc2311e1",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "c2531db6de3c95551be58878f859c6a053b7eb2e",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "95fc45d1dea8e1253f8ec58abc5befb71553d666",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"status": "affected",
"version": "7f93d703e276311dd289c9a520ce9e8c8fa2858c",
"versionType": "git"
},
{
"status": "affected",
"version": "c0e93a6d36135d5082cb3af8352f5b69c9f58d6e",
"versionType": "git"
},
{
"status": "affected",
"version": "c39b8fd4997bf99503b8e48d8cb0eedb1d9a54f0",
"versionType": "git"
},
{
"status": "affected",
"version": "26a5adc8eb26d170058645c3cccd4d19165bec16",
"versionType": "git"
},
{
"status": "affected",
"version": "3e881d8764ed9b04ae3e5c3e5d132acb75ef91ba",
"versionType": "git"
},
{
"status": "affected",
"version": "77768c96dcf860c43b970b87b2a09229f84ea560",
"versionType": "git"
},
{
"lessThan": "3.19",
"status": "affected",
"version": "3.18.132",
"versionType": "semver"
},
{
"lessThan": "4.5",
"status": "affected",
"version": "4.4.170",
"versionType": "semver"
},
{
"lessThan": "4.10",
"status": "affected",
"version": "4.9.149",
"versionType": "semver"
},
{
"lessThan": "4.15",
"status": "affected",
"version": "4.14.92",
"versionType": "semver"
},
{
"lessThan": "4.20",
"status": "affected",
"version": "4.19.14",
"versionType": "semver"
},
{
"lessThan": "4.21",
"status": "affected",
"version": "4.20.1",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/linux/netdevice.h",
"include/net/ax25.h",
"net/ax25/af_ax25.c",
"net/ax25/ax25_dev.c",
"net/ax25/ax25_ip.c",
"net/ax25/ax25_out.c",
"net/ax25/ax25_route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.0"
},
{
"lessThan": "5.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.129",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.76",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.13.*",
"status": "unaffected",
"version": "6.13.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.14",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "FB301D8A-4CE6-493F-94B4-AFA5737C1EC1",
"versionEndExcluding": "3.19",
"versionStartIncluding": "3.18.132",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "6D2CF938-4FA1-416D-AC49-F221731F57ED",
"versionEndExcluding": "4.5",
"versionStartIncluding": "4.4.170",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "2190C728-9805-46C1-BD8D-005E50F0EEB9",
"versionEndExcluding": "4.10",
"versionStartIncluding": "4.9.149",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "38A1AC7C-17D5-4E10-97A0-ED3637CD9D40",
"versionEndExcluding": "4.15",
"versionStartIncluding": "4.14.92",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "9C3378FE-6F2A-4485-958F-60A3779C280F",
"versionEndExcluding": "4.20",
"versionStartIncluding": "4.19.14",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "F12C53B3-1DD7-47D6-857F-A60A2DB0DF0A",
"versionEndExcluding": "6.1.129",
"versionStartIncluding": "4.20.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "A6D70701-9CB6-4222-A957-00A419878993",
"versionEndExcluding": "6.6.76",
"versionStartIncluding": "6.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "2897389C-A8C3-4D69-90F2-E701B3D66373",
"versionEndExcluding": "6.12.13",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "6D4116B1-1BFD-4F23-BA84-169CC05FC5A3",
"versionEndExcluding": "6.13.2",
"versionStartIncluding": "6.13",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nax25: rcu protect dev-\u003eax25_ptr\n\nsyzbot found a lockdep issue [1].\n\nWe should remove ax25 RTNL dependency in ax25_setsockopt()\n\nThis should also fix a variety of possible UAF in ax25.\n\n[1]\n\nWARNING: possible circular locking dependency detected\n6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted\n------------------------------------------------------\nsyz.5.1818/12806 is trying to acquire lock:\n ffffffff8fcb3988 (rtnl_mutex){+.+.}-{4:4}, at: ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680\n\nbut task is already holding lock:\n ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]\n ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-\u003e #1 (sk_lock-AF_AX25){+.+.}-{0:0}:\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849\n lock_sock_nested+0x48/0x100 net/core/sock.c:3642\n lock_sock include/net/sock.h:1618 [inline]\n ax25_kill_by_device net/ax25/af_ax25.c:101 [inline]\n ax25_device_event+0x24d/0x580 net/ax25/af_ax25.c:146\n notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85\n __dev_notify_flags+0x207/0x400\n dev_change_flags+0xf0/0x1a0 net/core/dev.c:9026\n dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:563\n dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:820\n sock_do_ioctl+0x240/0x460 net/socket.c:1234\n sock_ioctl+0x626/0x8e0 net/socket.c:1339\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:906 [inline]\n __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n-\u003e #0 (rtnl_mutex){+.+.}-{4:4}:\n check_prev_add kernel/locking/lockdep.c:3161 [inline]\n check_prevs_add kernel/locking/lockdep.c:3280 [inline]\n validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904\n __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849\n __mutex_lock_common kernel/locking/mutex.c:585 [inline]\n __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735\n ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680\n do_sock_setsockopt+0x3af/0x720 net/socket.c:2324\n __sys_setsockopt net/socket.c:2349 [inline]\n __do_sys_setsockopt net/socket.c:2355 [inline]\n __se_sys_setsockopt net/socket.c:2352 [inline]\n __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nother info that might help us debug this:\n\n Possible unsafe locking scenario:\n\n CPU0 CPU1\n ---- ----\n lock(sk_lock-AF_AX25);\n lock(rtnl_mutex);\n lock(sk_lock-AF_AX25);\n lock(rtnl_mutex);\n\n *** DEADLOCK ***\n\n1 lock held by syz.5.1818/12806:\n #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]\n #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574\n\nstack backtrace:\nCPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120\n print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074\n check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206\n check_prev_add kernel/locking/lockdep.c:3161 [inline]\n check_prevs_add kernel/lockin\n---truncated---"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ax25: rcu protect dev-\u0026gt;ax25_ptr syzbot encontr\u00f3 un problema de lockdep [1]. Deber\u00edamos eliminar la dependencia RTNL de ax25 en ax25_setsockopt(). Esto tambi\u00e9n deber\u00eda solucionar una variedad de posibles UAF en ax25. [1] ADVERTENCIA: se detect\u00f3 una posible dependencia de bloqueo circular 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted ------------------------------------------------------ syz.5.1818/12806 is trying to acquire lock: ffffffff8fcb3988 (rtnl_mutex){+.+.}-{4:4}, at: ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680 but task is already holding lock: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline] ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -\u0026gt; #1 (sk_lock-AF_AX25){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 lock_sock_nested+0x48/0x100 net/core/sock.c:3642 lock_sock include/net/sock.h:1618 [inline] ax25_kill_by_device net/ax25/af_ax25.c:101 [inline] ax25_device_event+0x24d/0x580 net/ax25/af_ax25.c:146 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 __dev_notify_flags+0x207/0x400 dev_change_flags+0xf0/0x1a0 net/core/dev.c:9026 dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:563 dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:820 sock_do_ioctl+0x240/0x460 net/socket.c:1234 sock_ioctl+0x626/0x8e0 net/socket.c:1339 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -\u0026gt; #0 (rtnl_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680 do_sock_setsockopt+0x3af/0x720 net/socket.c:2324 __sys_setsockopt net/socket.c:2349 [inline] __do_sys_setsockopt net/socket.c:2355 [inline] __se_sys_setsockopt net/socket.c:2352 [inline] __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_AX25); lock(rtnl_mutex); lock(sk_lock-AF_AX25); lock(rtnl_mutex); *** DEADLOCK *** 1 lock held by syz.5.1818/12806: #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline] #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574 stack backtrace: CPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/lockin ---truncated--- "
}
],
"id": "CVE-2025-21812",
"lastModified": "2026-06-17T08:44:20.233",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2025-21812",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-03-04T18:00:00.916644Z",
"version": "2.0.3"
}
}
]
},
"published": "2025-02-27T20:16:03.783",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/2802ed4ced27ebd474828fc67ffd7d66f11e3605"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/7705d8a7f2c26c80973c81093db07c6022b2b30e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/8937f5e38a218531dce2a89fae60e3adcc2311e1"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/95fc45d1dea8e1253f8ec58abc5befb71553d666"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/c2531db6de3c95551be58878f859c6a053b7eb2e"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-08-13T17:51:40+00:00",
"cve": "CVE-2025-21812",
"id": "CVE-2025-21812",
"initial_release_date": "2025-02-27T00:00:00+00:00",
"product_status:known_not_affected": "274",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: ax25: rcu protect dev-\u003eax25_ptr",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-21812.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2025-11-03T20:59:48.635Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
},
{
"other": {
"content": {
"id": "CVE-2025-21812",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-03-04T18:00:00.916644Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-416",
"description": "CWE-416 Use After Free",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2025-03-04T18:00:02.524Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/netdevice.h",
"include/net/ax25.h",
"net/ax25/af_ax25.c",
"net/ax25/ax25_dev.c",
"net/ax25/ax25_ip.c",
"net/ax25/ax25_out.c",
"net/ax25/ax25_route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2802ed4ced27ebd474828fc67ffd7d66f11e3605",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "7705d8a7f2c26c80973c81093db07c6022b2b30e",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "8937f5e38a218531dce2a89fae60e3adcc2311e1",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "c2531db6de3c95551be58878f859c6a053b7eb2e",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"lessThan": "95fc45d1dea8e1253f8ec58abc5befb71553d666",
"status": "affected",
"version": "c433570458e49bccea5c551df628d058b3526289",
"versionType": "git"
},
{
"status": "affected",
"version": "7f93d703e276311dd289c9a520ce9e8c8fa2858c",
"versionType": "git"
},
{
"status": "affected",
"version": "c0e93a6d36135d5082cb3af8352f5b69c9f58d6e",
"versionType": "git"
},
{
"status": "affected",
"version": "c39b8fd4997bf99503b8e48d8cb0eedb1d9a54f0",
"versionType": "git"
},
{
"status": "affected",
"version": "26a5adc8eb26d170058645c3cccd4d19165bec16",
"versionType": "git"
},
{
"status": "affected",
"version": "3e881d8764ed9b04ae3e5c3e5d132acb75ef91ba",
"versionType": "git"
},
{
"status": "affected",
"version": "77768c96dcf860c43b970b87b2a09229f84ea560",
"versionType": "git"
},
{
"lessThan": "3.19",
"status": "affected",
"version": "3.18.132",
"versionType": "semver"
},
{
"lessThan": "4.5",
"status": "affected",
"version": "4.4.170",
"versionType": "semver"
},
{
"lessThan": "4.10",
"status": "affected",
"version": "4.9.149",
"versionType": "semver"
},
{
"lessThan": "4.15",
"status": "affected",
"version": "4.14.92",
"versionType": "semver"
},
{
"lessThan": "4.20",
"status": "affected",
"version": "4.19.14",
"versionType": "semver"
},
{
"lessThan": "4.21",
"status": "affected",
"version": "4.20.1",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/linux/netdevice.h",
"include/net/ax25.h",
"net/ax25/af_ax25.c",
"net/ax25/ax25_dev.c",
"net/ax25/ax25_ip.c",
"net/ax25/ax25_out.c",
"net/ax25/ax25_route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.0"
},
{
"lessThan": "5.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.129",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.76",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.13.*",
"status": "unaffected",
"version": "6.13.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.14",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.129",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.76",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.13",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.13.2",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.14",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "3.18.132",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.4.170",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.9.149",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.14.92",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.19.14",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.20.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nax25: rcu protect dev-\u003eax25_ptr\n\nsyzbot found a lockdep issue [1].\n\nWe should remove ax25 RTNL dependency in ax25_setsockopt()\n\nThis should also fix a variety of possible UAF in ax25.\n\n[1]\n\nWARNING: possible circular locking dependency detected\n6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted\n------------------------------------------------------\nsyz.5.1818/12806 is trying to acquire lock:\n ffffffff8fcb3988 (rtnl_mutex){+.+.}-{4:4}, at: ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680\n\nbut task is already holding lock:\n ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]\n ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-\u003e #1 (sk_lock-AF_AX25){+.+.}-{0:0}:\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849\n lock_sock_nested+0x48/0x100 net/core/sock.c:3642\n lock_sock include/net/sock.h:1618 [inline]\n ax25_kill_by_device net/ax25/af_ax25.c:101 [inline]\n ax25_device_event+0x24d/0x580 net/ax25/af_ax25.c:146\n notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85\n __dev_notify_flags+0x207/0x400\n dev_change_flags+0xf0/0x1a0 net/core/dev.c:9026\n dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:563\n dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:820\n sock_do_ioctl+0x240/0x460 net/socket.c:1234\n sock_ioctl+0x626/0x8e0 net/socket.c:1339\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:906 [inline]\n __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n-\u003e #0 (rtnl_mutex){+.+.}-{4:4}:\n check_prev_add kernel/locking/lockdep.c:3161 [inline]\n check_prevs_add kernel/locking/lockdep.c:3280 [inline]\n validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904\n __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849\n __mutex_lock_common kernel/locking/mutex.c:585 [inline]\n __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735\n ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680\n do_sock_setsockopt+0x3af/0x720 net/socket.c:2324\n __sys_setsockopt net/socket.c:2349 [inline]\n __do_sys_setsockopt net/socket.c:2355 [inline]\n __se_sys_setsockopt net/socket.c:2352 [inline]\n __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nother info that might help us debug this:\n\n Possible unsafe locking scenario:\n\n CPU0 CPU1\n ---- ----\n lock(sk_lock-AF_AX25);\n lock(rtnl_mutex);\n lock(sk_lock-AF_AX25);\n lock(rtnl_mutex);\n\n *** DEADLOCK ***\n\n1 lock held by syz.5.1818/12806:\n #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]\n #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574\n\nstack backtrace:\nCPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120\n print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074\n check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206\n check_prev_add kernel/locking/lockdep.c:3161 [inline]\n check_prevs_add kernel/lockin\n---truncated---"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The controllable attack path is an AF_AX25 socket driven by local syscalls (setsockopt SO_BINDTODEVICE, connect/sendmsg autobind, close), which is what both frees the ax25_dev and re-dereferences the dangling dev-\u003eax25_ptr. Although received AX.25 frames also read dev-\u003eax25_ptr in ax25_rcv(), an adjacent radio/L2 peer cannot itself cause the free, so the attacker must be local.\nAC:L - No race needs to be won: SO_BINDTODEVICE stores ax25-\u003eax25_dev without a reference while ax25_release() drops one, so a single setsockopt+close deterministically drives the refcount to zero and kfree()s the object still published in dev-\u003eax25_ptr. The pure device-down race variant is also attacker-driven by spinning setsockopt/connect in a loop.\nPR:L - ax25_create() imposes no capability check for SOCK_DGRAM/SOCK_SEQPACKET, and the AF_AX25 module autoloads via the net-pf-3 alias, so any unprivileged local user in the init namespace can reach every vulnerable path. Root is only needed for the one-time deployment setup of the AX.25 port, not by the attacker.\nUI:N - The entire sequence is performed by the attacker\u0027s own process through socket(), setsockopt(), connect()/sendmsg() and close(); no victim action is involved.\nS:U - The freed ax25_dev and the corrupted kernel heap are entirely within the kernel\u0027s own security authority, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - After the free, ax25_fillin_cb() copies bytes from the reclaimed slab object into the socket\u0027s t1/t2/t3/n2/paclen/window/backoff fields, which userspace reads back with getsockopt() \u2014 a direct kernel heap disclosure \u2014 and the general UAF read of ax25_dev-\u003edev/-\u003eforward enables broader information leakage.\nI:H - The dangling pointer yields repeated refcount_dec() and stores to ax25_dev-\u003eforward and -\u003edevice_up into memory that has been reallocated for other kernel objects, giving a controlled decrement/write primitive on a groomed heap that is exploitable for privilege escalation.\nA:H - Dereferencing and freeing the already-freed ax25_dev reliably produces a kernel oops/panic (and netdev refcount underflow), and the same commit fixes a genuine sk_lock-AF_AX25 versus rtnl_mutex ABBA deadlock that permanently wedges the rtnl mutex and with it the entire networking stack."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T11:54:40.014Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/2802ed4ced27ebd474828fc67ffd7d66f11e3605"
},
{
"url": "https://git.kernel.org/stable/c/7705d8a7f2c26c80973c81093db07c6022b2b30e"
},
{
"url": "https://git.kernel.org/stable/c/8937f5e38a218531dce2a89fae60e3adcc2311e1"
},
{
"url": "https://git.kernel.org/stable/c/c2531db6de3c95551be58878f859c6a053b7eb2e"
},
{
"url": "https://git.kernel.org/stable/c/95fc45d1dea8e1253f8ec58abc5befb71553d666"
}
],
"title": "ax25: rcu protect dev-\u003eax25_ptr",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-21812",
"datePublished": "2025-02-27T20:01:02.837Z",
"dateReserved": "2024-12-29T08:45:45.774Z",
"dateUpdated": "2026-08-05T11:54:40.014Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…