OESA-2026-1949 (CVE-2025-68291)
Vulnerability from osv_openeuler – Published: 2026-04-17 11:10 – Updated: 2026-08-06 11:10 – Source websiteThe Linux Kernel, the operating system core itself.
Security Fix(es):
In the Linux kernel, the following vulnerability has been resolved:
mptcp: Initialise rcv_mss before calling tcp_send_active_reset() in mptcp_do_fastclose().
syzbot reported divide-by-zero in __tcp_select_window() by MPTCP socket. [0]
We had a similar issue for the bare TCP and fixed in commit 499350a5a6e7 ("tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0").
Let's apply the same fix to mptcp_do_fastclose().
[0]: Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 6068 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__tcp_select_window+0x824/0x1320 net/ipv4/tcp_output.c:3336 Code: ff ff ff 44 89 f1 d3 e0 89 c1 f7 d1 41 01 cc 41 21 c4 e9 a9 00 00 00 e8 ca 49 01 f8 e9 9c 00 00 00 e8 c0 49 01 f8 44 89 e0 99 <f7> 7c 24 1c 41 29 d4 48 bb 00 00 00 00 00 fc ff df e9 80 00 00 00 RSP: 0018:ffffc90003017640 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807b469e40 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003017730 R08: ffff888033268143 R09: 1ffff1100664d028 R10: dffffc0000000000 R11: ffffed100664d029 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 000055557faa0500(0000) GS:ffff888126135000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f64a1912ff8 CR3: 0000000072122000 CR4: 00000000003526f0 Call Trace: <TASK> tcp_select_window net/ipv4/tcp_output.c:281 [inline] __tcp_transmit_skb+0xbc7/0x3aa0 net/ipv4/tcp_output.c:1568 tcp_transmit_skb net/ipv4/tcp_output.c:1649 [inline] tcp_send_active_reset+0x2d1/0x5b0 net/ipv4/tcp_output.c:3836 mptcp_do_fastclose+0x27e/0x380 net/mptcp/protocol.c:2793 mptcp_disconnect+0x238/0x710 net/mptcp/protocol.c:3253 mptcp_sendmsg_fastopen+0x2f8/0x580 net/mptcp/protocol.c:1776 mptcp_sendmsg+0x1774/0x1980 net/mptcp/protocol.c:1855 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe5/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66e998f749 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:00007ffff9acedb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f66e9be5fa0 RCX: 00007f66e998f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffff9acee10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f66e9be5fa0 R14: 00007f66e9be5fa0 R15: 0000000000000006 </TASK>(CVE-2025-68291)
| URL | Type | |
|---|---|---|
{
"affected": [
{
"ecosystem_specific": {
"aarch64": [
"bpftool-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"bpftool-debuginfo-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-debuginfo-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-debugsource-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-devel-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-extra-modules-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-headers-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-source-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-tools-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-tools-debuginfo-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"kernel-tools-devel-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"perf-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"perf-debuginfo-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"python3-perf-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm",
"python3-perf-debuginfo-6.6.0-145.0.3.134.oe2403sp3.aarch64.rpm"
],
"src": [
"kernel-6.6.0-145.0.3.134.oe2403sp3.src.rpm"
],
"x86_64": [
"bpftool-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"bpftool-debuginfo-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-debuginfo-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-debugsource-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-devel-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-extra-modules-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-headers-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-source-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-tools-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-tools-debuginfo-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"kernel-tools-devel-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"perf-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"perf-debuginfo-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"python3-perf-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm",
"python3-perf-debuginfo-6.6.0-145.0.3.134.oe2403sp3.x86_64.rpm"
]
},
"package": {
"ecosystem": "openEuler:24.03-LTS-SP3",
"name": "kernel",
"purl": "pkg:rpm/openEuler/kernel\u0026distro=openEuler-24.03-LTS-SP3"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.6.0-145.0.3.134.oe2403sp3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"severity": "High"
},
"details": "The Linux Kernel, the operating system core itself.\r\n\r\nSecurity Fix(es):\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: Initialise rcv_mss before calling tcp_send_active_reset() in mptcp_do_fastclose().\n\nsyzbot reported divide-by-zero in __tcp_select_window() by\nMPTCP socket. [0]\n\nWe had a similar issue for the bare TCP and fixed in commit\n499350a5a6e7 (\u0026quot;tcp: initialize rcv_mss to TCP_MIN_MSS instead\nof 0\u0026quot;).\n\nLet\u0026apos;s apply the same fix to mptcp_do_fastclose().\n\n[0]:\nOops: divide error: 0000 [#1] SMP KASAN PTI\nCPU: 0 UID: 0 PID: 6068 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025\nRIP: 0010:__tcp_select_window+0x824/0x1320 net/ipv4/tcp_output.c:3336\nCode: ff ff ff 44 89 f1 d3 e0 89 c1 f7 d1 41 01 cc 41 21 c4 e9 a9 00 00 00 e8 ca 49 01 f8 e9 9c 00 00 00 e8 c0 49 01 f8 44 89 e0 99 \u0026lt;f7\u0026gt; 7c 24 1c 41 29 d4 48 bb 00 00 00 00 00 fc ff df e9 80 00 00 00\nRSP: 0018:ffffc90003017640 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807b469e40\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\nRBP: ffffc90003017730 R08: ffff888033268143 R09: 1ffff1100664d028\nR10: dffffc0000000000 R11: ffffed100664d029 R12: 0000000000000000\nR13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\nFS: 000055557faa0500(0000) GS:ffff888126135000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f64a1912ff8 CR3: 0000000072122000 CR4: 00000000003526f0\nCall Trace:\n \u0026lt;TASK\u0026gt;\n tcp_select_window net/ipv4/tcp_output.c:281 [inline]\n __tcp_transmit_skb+0xbc7/0x3aa0 net/ipv4/tcp_output.c:1568\n tcp_transmit_skb net/ipv4/tcp_output.c:1649 [inline]\n tcp_send_active_reset+0x2d1/0x5b0 net/ipv4/tcp_output.c:3836\n mptcp_do_fastclose+0x27e/0x380 net/mptcp/protocol.c:2793\n mptcp_disconnect+0x238/0x710 net/mptcp/protocol.c:3253\n mptcp_sendmsg_fastopen+0x2f8/0x580 net/mptcp/protocol.c:1776\n mptcp_sendmsg+0x1774/0x1980 net/mptcp/protocol.c:1855\n sock_sendmsg_nosec net/socket.c:727 [inline]\n __sock_sendmsg+0xe5/0x270 net/socket.c:742\n __sys_sendto+0x3bd/0x520 net/socket.c:2244\n __do_sys_sendto net/socket.c:2251 [inline]\n __se_sys_sendto net/socket.c:2247 [inline]\n __x64_sys_sendto+0xde/0x100 net/socket.c:2247\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f66e998f749\nCode: 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 \u0026lt;48\u0026gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007ffff9acedb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 00007f66e9be5fa0 RCX: 00007f66e998f749\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003\nRBP: 00007ffff9acee10 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001\nR13: 00007f66e9be5fa0 R14: 00007f66e9be5fa0 R15: 0000000000000006\n \u0026lt;/TASK\u0026gt;(CVE-2025-68291)",
"id": "OESA-2026-1949",
"modified": "2026-08-06T11:10:57Z",
"published": "2026-04-17T11:10:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-1949"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-68291"
}
],
"schema_version": "1.7.2",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "kernel security update",
"upstream": [
"CVE-2025-68291"
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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