CVE-2025-21875
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-21875
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21875.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-21875
- Downstream
- Related
- Published
- 2025-03-27T14:57:06Z
- Modified
- 2025-10-18T00:00:56.716553Z
- Summary
- mptcp: always handle address removal under msk socket lock
- Details
-
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 sockownedbyme include/net/sock.h:1711 [inline] WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 mskownedbyme net/mptcp/protocol.h:363 [inline] WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 mptcppmnladdrsendack+0x57c/0x610 net/mptcp/pmnetlink.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:sockownedbyme include/net/sock.h:1711 [inline] RIP: 0010:mskownedbyme net/mptcp/protocol.h:363 [inline] RIP: 0010:mptcppmnladdrsendack+0x57c/0x610 net/mptcp/pmnetlink.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> mptcppmremoveaddr+0x103/0x1d0 net/mptcp/pm.c:59 mptcppmremoveannoaddr+0x1f4/0x2f0 net/mptcp/pmnetlink.c:1486 mptcpnlremovesubflowandsignaladdr net/mptcp/pmnetlink.c:1518 [inline] mptcppmnldeladdrdoit+0x118d/0x1af0 net/mptcp/pmnetlink.c:1629 genlfamilyrcvmsgdoit net/netlink/genetlink.c:1115 [inline] genlfamilyrcvmsg net/netlink/genetlink.c:1195 [inline] genlrcvmsg+0xb1f/0xec0 net/netlink/genetlink.c:1210 netlinkrcvskb+0x206/0x480 net/netlink/afnetlink.c:2543 genlrcv+0x28/0x40 net/netlink/genetlink.c:1219 netlinkunicastkernel net/netlink/afnetlink.c:1322 [inline] netlinkunicast+0x7f6/0x990 net/netlink/afnetlink.c:1348 netlinksendmsg+0x8de/0xcb0 net/netlink/afnetlink.c:1892 socksendmsgnosec net/socket.c:718 [inline] socksendmsg+0x221/0x270 net/socket.c:733 syssendmsg+0x53a/0x860 net/socket.c:2573 _syssendmsg net/socket.c:2627 [inline] _syssendmsg+0x269/0x350 net/socket.c:2659 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf3/0x230 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+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---
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/2c3de6dff4373f1036e003f49a32629359530bdb
- https://git.kernel.org/stable/c/4124b782ec2b1e2e490cf0bbf10f53dfd3479890
- 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/f865c24bc55158313d5779fc81116023a6940ca3
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixed494ec285535632732eaa5786297a9ae4f731b5ff
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixed7cca31035c05819643ffb5d7518e9a331b3f6651
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixed8116fb4acd5d3f06cd37f84887dbe962b6703b1c
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixeda05da2be18aae7e82572f8d795f41bb49f5dfc7d
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixed4124b782ec2b1e2e490cf0bbf10f53dfd3479890
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixed2c3de6dff4373f1036e003f49a32629359530bdb
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6c08380860b926752d57c8fa9911fa388c4b876Fixedf865c24bc55158313d5779fc81116023a6940ca3
Affected versions
v5.*
v6.*
Linux / Kernel
Package
- Name
- Kernel
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced5.10.0Fixed5.10.235
- Type
- ECOSYSTEM
- Events
-
Introduced5.11.0Fixed5.15.179
- Type
- ECOSYSTEM
- Events
-
Introduced5.16.0Fixed6.1.130
- Type
- ECOSYSTEM
- Events
-
Introduced6.2.0Fixed6.6.81
- Type
- ECOSYSTEM
- Events
-
Introduced6.7.0Fixed6.12.18
- Type
- ECOSYSTEM
- Events
-
Introduced6.13.0Fixed6.13.6