CVE-2025-21875
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: always handle address removal under msk socket lock Syzkaller reported a lockdep splat in the PM control path: WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 sock_owned_by_me include/net/sock.h:1711 [inline] WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 msk_owned_by_me net/mptcp/protocol.h:363 [inline] WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788 Modules linked in: CPU: 0 UID: 0 PID: 6693 Comm: syz.0.205 Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:sock_owned_by_me include/net/sock.h:1711 [inline] RIP: 0010:msk_owned_by_me net/mptcp/protocol.h:363 [inline] RIP: 0010:mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788 Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ca 7b d3 f5 eb b9 e8 c3 7b d3 f5 90 0f 0b 90 e9 dd fb ff ff e8 b5 7b d3 f5 90 <0f> 0b 90 e9 3e fb ff ff 44 89 f1 80 e1 07 38 c1 0f 8c eb fb ff ff RSP: 0000:ffffc900034f6f60 EFLAGS: 00010283 RAX: ffffffff8bee3c2b RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc90004d42000 RSI: 000000000000a407 RDI: 000000000000a408 RBP: ffffc900034f7030 R08: ffffffff8bee37f6 R09: 0100000000000000 R10: dffffc0000000000 R11: ffffed100bcc62e4 R12: ffff88805e6316e0 R13: ffff88805e630c00 R14: dffffc0000000000 R15: ffff88805e630c00 FS: 00007f7e9a7e96c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fd18ff8 CR3: 0000000032c24000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> mptcp_pm_remove_addr+0x103/0x1d0 net/mptcp/pm.c:59 mptcp_pm_remove_anno_addr+0x1f4/0x2f0 net/mptcp/pm_netlink.c:1486 mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_netlink.c:1518 [inline] mptcp_pm_nl_del_addr_doit+0x118d/0x1af0 net/mptcp/pm_netlink.c:1629 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb1f/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 ____sys_sendmsg+0x53a/0x860 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2659 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 RIP: 0033:0x7f7e9998cde9 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 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7e9a7e9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7e99ba5fa0 RCX: 00007f7e9998cde9 RDX: 000000002000c094 RSI: 0000400000000000 RDI: 0000000000000007 RBP: 00007f7e99a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7e99ba5fa0 R15: 00007fff49231088 Indeed the PM can try to send a RM_ADDR over a msk without acquiring first the msk socket lock. The bugged code-path comes from an early optimization: when there are no subflows, the PM should (usually) not send RM_ADDR notifications. The above statement is incorrect, as without locks another process could concur ---truncated---
CVSS Metrics
- v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Trends
Current EPSS score: 0.22%• Percentile: 13%
Affected Systems
- debian•linux
< 5.10.237-1 | < 6.1.133-1 | < 6.12.19-1 | < 6.12.19-1
- debian•linux-6.1
< 6.1.137-1~deb11u1
- ubuntu•linux
< 5.15.0-140.150 | < 6.8.0-84.84
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
< 5.15.0-1084.91 | < 6.8.0-1039.41
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.15
< 5.15.0-1084.91~20.04.1
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
< 6.8.0-1039.41~22.04.1
- ubuntu•linux-aws-fips
all | < 5.15.0-1084.91+fips1 | < 6.8.0-1039.41+fips1
- ubuntu•linux-azure
all | < 5.15.0-1089.98 | < 6.8.0-1038.44
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.15
< 5.15.0-1089.98~20.04.1
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
< 6.11.0-1015.15~24.04.1
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
< 6.8.0-1036.42~22.04.1
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fips
all | < 5.15.0-1089.98+fips1 | < 6.8.0-1040.46+fips1
- ubuntu•linux-azure-nvidia
< 6.8.0-1025.27
- ubuntu•linux-bluefield
all | < 5.15.0-1066.68
- ubuntu•linux-fips
all | < 5.15.0-140.150+fips1 | < 6.8.0-84.84+fips1
- ubuntu•linux-gcp
all | < 5.15.0-1083.92 | < 6.8.0-1040.42
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
- ubuntu•linux-gcp-5.15
< 5.15.0-1083.92~20.04.1
- ubuntu•linux-gcp-5.19
all
- ubuntu•linux-gcp-5.3
all
- ubuntu•linux-gcp-5.8
all
- ubuntu•linux-gcp-6.11
< 6.11.0-1015.15~24.04.1
- ubuntu•linux-gcp-6.2
all
- ubuntu•linux-gcp-6.5
all
- ubuntu•linux-gcp-6.8
< 6.8.0-1040.42~22.04.1
- ubuntu•linux-gcp-fips
all | < 5.15.0-1083.92+fips1 | < 6.8.0-1040.42+fips1
- ubuntu•linux-gke
all | < 5.15.0-1081.87 | < 6.8.0-1036.40
- ubuntu•linux-gke-4.15
all
- ubuntu•linux-gke-5.15
all
Showing first 50 affected entries in server-rendered view.
References (45)
- https://git.kernel.org/stable/c/494ec285535632732eaa5786297a9ae4f731b5ff
- https://git.kernel.org/stable/c/7cca31035c05819643ffb5d7518e9a331b3f6651
- https://git.kernel.org/stable/c/8116fb4acd5d3f06cd37f84887dbe962b6703b1c
- https://git.kernel.org/stable/c/a05da2be18aae7e82572f8d795f41bb49f5dfc7d
- https://git.kernel.org/stable/c/4124b782ec2b1e2e490cf0bbf10f53dfd3479890
- https://git.kernel.org/stable/c/2c3de6dff4373f1036e003f49a32629359530bdb
- https://git.kernel.org/stable/c/f865c24bc55158313d5779fc81116023a6940ca3
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://ubuntu.com/security/CVE-2025-21875
- https://www.cve.org/CVERecord?id=CVE-2025-21875
- https://git.kernel.org/linus/f865c24bc55158313d5779fc81116023a6940ca3
- https://ubuntu.com/security/notices/USN-7510-1
- https://ubuntu.com/security/notices/USN-7510-2
- https://ubuntu.com/security/notices/USN-7511-1
- https://ubuntu.com/security/notices/USN-7511-2
- https://ubuntu.com/security/notices/USN-7512-1
- https://ubuntu.com/security/notices/USN-7521-1
- https://ubuntu.com/security/notices/USN-7510-3
- https://ubuntu.com/security/notices/USN-7510-4
- https://ubuntu.com/security/notices/USN-7510-5
- https://ubuntu.com/security/notices/USN-7511-3
- https://ubuntu.com/security/notices/USN-7521-2
- https://ubuntu.com/security/notices/USN-7510-6
- https://ubuntu.com/security/notices/USN-7521-3
- https://ubuntu.com/security/notices/USN-7510-7
- https://ubuntu.com/security/notices/USN-7510-8
- https://ubuntu.com/security/notices/USN-7593-1
- https://ubuntu.com/security/notices/USN-7602-1
- https://ubuntu.com/security/notices/USN-7764-1
- https://ubuntu.com/security/notices/USN-7765-1
- https://ubuntu.com/security/notices/USN-7766-1
- https://ubuntu.com/security/notices/USN-7767-1
- https://ubuntu.com/security/notices/USN-7779-1
- https://ubuntu.com/security/notices/USN-7767-2
- https://ubuntu.com/security/notices/USN-7764-2
- https://ubuntu.com/security/notices/USN-7790-1
- https://ubuntu.com/security/notices/USN-7800-1
- https://ubuntu.com/security/notices/USN-7801-1
- https://ubuntu.com/security/notices/USN-7802-1
- https://ubuntu.com/security/notices/USN-7801-2
- https://ubuntu.com/security/notices/USN-7809-1
- https://ubuntu.com/security/notices/USN-7801-3
- https://security-tracker.debian.org/tracker/CVE-2025-21875