{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2025-21812", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-21812", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2025-02-27T20:01:02.837Z", "updatedAt": "2026-08-05T11:54:40.014Z", "importedAt": "2026-10-24T01:57:29.455Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "ax25: rcu protect dev->ax25_ptr", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nax25: rcu protect dev->ax25_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-> #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-> #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 \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---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "c433570458e49bccea5c551df628d058b3526289", "status": "affected", "versionType": "git", "lessThan": "2802ed4ced27ebd474828fc67ffd7d66f11e3605" }, { "version": "c433570458e49bccea5c551df628d058b3526289", "status": "affected", "versionType": "git", "lessThan": "7705d8a7f2c26c80973c81093db07c6022b2b30e" }, { "version": "c433570458e49bccea5c551df628d058b3526289", "status": "affected", "versionType": "git", "lessThan": "8937f5e38a218531dce2a89fae60e3adcc2311e1" }, { "version": "c433570458e49bccea5c551df628d058b3526289", "status": "affected", "versionType": "git", "lessThan": "c2531db6de3c95551be58878f859c6a053b7eb2e" }, { "version": "c433570458e49bccea5c551df628d058b3526289", "status": "affected", "versionType": "git", "lessThan": "95fc45d1dea8e1253f8ec58abc5befb71553d666" }, { "version": "7f93d703e276311dd289c9a520ce9e8c8fa2858c", "status": "affected", "versionType": "git" }, { "version": "c0e93a6d36135d5082cb3af8352f5b69c9f58d6e", "status": "affected", "versionType": "git" }, { "version": "c39b8fd4997bf99503b8e48d8cb0eedb1d9a54f0", "status": "affected", "versionType": "git" }, { "version": "26a5adc8eb26d170058645c3cccd4d19165bec16", "status": "affected", "versionType": "git" }, { "version": "3e881d8764ed9b04ae3e5c3e5d132acb75ef91ba", "status": "affected", "versionType": "git" }, { "version": "77768c96dcf860c43b970b87b2a09229f84ea560", "status": "affected", "versionType": "git" }, { "version": "3.18.132", "status": "affected", "versionType": "semver", "lessThan": "3.19" }, { "version": "4.4.170", "status": "affected", "versionType": "semver", "lessThan": "4.5" }, { "version": "4.9.149", "status": "affected", "versionType": "semver", "lessThan": "4.10" }, { "version": "4.14.92", "status": "affected", "versionType": "semver", "lessThan": "4.15" }, { "version": "4.19.14", "status": "affected", "versionType": "semver", "lessThan": "4.20" }, { "version": "4.20.1", "status": "affected", "versionType": "semver", "lessThan": "4.21" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.0" }, { "version": "6.1.129", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.76", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.13", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.13.2", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.13.*" }, { "version": "6.14", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }