ghsa-5qmp-w6rv-24wf
Vulnerability from github
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: __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---
{
"affected": [],
"aliases": [
"CVE-2025-21812"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-27T20:16:03Z",
"severity": "HIGH"
},
"details": "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---",
"id": "GHSA-5qmp-w6rv-24wf",
"modified": "2025-03-04T18:33:26Z",
"published": "2025-02-27T21:32:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21812"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2802ed4ced27ebd474828fc67ffd7d66f11e3605"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7705d8a7f2c26c80973c81093db07c6022b2b30e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8937f5e38a218531dce2a89fae60e3adcc2311e1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/95fc45d1dea8e1253f8ec58abc5befb71553d666"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c2531db6de3c95551be58878f859c6a053b7eb2e"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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