{"id":"DEBIAN-CVE-2025-21862","details":"In the Linux kernel, the following vulnerability has been resolved:  drop_monitor: fix incorrect initialization order  Syzkaller reports the following bug:  BUG: spinlock bad magic on CPU#1, syz-executor.0/7995  lock: 0xffff88805303f3e0, .magic: 00000000, .owner: \u003cnone\u003e/-1, .owner_cpu: 0 CPU: 1 PID: 7995 Comm: syz-executor.0 Tainted: G            E     5.10.209+ #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace:  __dump_stack lib/dump_stack.c:77 [inline]  dump_stack+0x119/0x179 lib/dump_stack.c:118  debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]  do_raw_spin_lock+0x1f6/0x270 kernel/locking/spinlock_debug.c:112  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline]  _raw_spin_lock_irqsave+0x50/0x70 kernel/locking/spinlock.c:159  reset_per_cpu_data+0xe6/0x240 [drop_monitor]  net_dm_cmd_trace+0x43d/0x17a0 [drop_monitor]  genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739  genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]  genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800  netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2497  genl_rcv+0x29/0x40 net/netlink/genetlink.c:811  netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]  netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1348  netlink_sendmsg+0x914/0xe00 net/netlink/af_netlink.c:1916  sock_sendmsg_nosec net/socket.c:651 [inline]  __sock_sendmsg+0x157/0x190 net/socket.c:663  ____sys_sendmsg+0x712/0x870 net/socket.c:2378  ___sys_sendmsg+0xf8/0x170 net/socket.c:2432  __sys_sendmsg+0xea/0x1b0 net/socket.c:2461  do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46  entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7f3f9815aee9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3f972bf0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3f9826d050 RCX: 00007f3f9815aee9 RDX: 0000000020000000 RSI: 0000000020001300 RDI: 0000000000000007 RBP: 00007f3f981b63bd R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f3f9826d050 R15: 00007ffe01ee6768  If drop_monitor is built as a kernel module, syzkaller may have time to send a netlink NET_DM_CMD_START message during the module loading. This will call the net_dm_monitor_start() function that uses a spinlock that has not yet been initialized.  To fix this, let's place resource initialization above the registration of a generic netlink family.  Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller.","modified":"2026-09-01T16:06:10.269367366Z","published":"2025-03-12T10:15:19.253Z","upstream":["CVE-2025-21862"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-21862"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.133-1"}]}],"versions":["6.1.106-1","6.1.106-2","6.1.106-3","6.1.112-1","6.1.115-1","6.1.119-1","6.1.123-1","6.1.124-1","6.1.128-1","6.1.129-1","6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21862.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.17-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21862.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.17-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21862.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}