An update for kernel is now available for openEuler-24.03-LTS-SP3 Security Advisory openeuler-security@openeuler.org openEuler security committee openEuler-SA-2026-1949 Final 1.0 1.0 2026-04-17 Initial 2026-04-17 2026-04-17 openEuler SA Tool V1.0 2026-04-17 kernel security update An update for kernel is now available for openEuler-24.03-LTS-SP3 The 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) An update for kernel is now available for openEuler-24.03-LTS-SP3. openEuler Security has rated this update as having a security impact of high. A Common Vunlnerability Scoring System(CVSS)base score,which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section. High kernel https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-1949 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2025-68291 https://nvd.nist.gov/vuln/detail/CVE-2025-68291 openEuler-24.03-LTS-SP3 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 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 kernel-6.6.0-145.0.3.134.oe2403sp3.src.rpm 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> 2026-04-17 CVE-2025-68291 openEuler-24.03-LTS-SP3 High 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H kernel security update 2026-04-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-1949