{ "cveId": "CVE-2026-43029", "url": "https://patchblox.com/security/cve/CVE-2026-43029", "summary": "CVE-2026-43029 is fixed in 19 products on 1 platform, first by DEBIAN-CVE-2026-43029, released May 15, 2026. It is not reported as exploited. Patch Radar priority: High.", "title": "mptcp: fix soft lockup in mptcp_recvmsg()", "description": "In the Linux kernel, the following vulnerability has been resolved: mptcp: fix soft lockup in mptcp_recvmsg() syzbot reported a soft lockup in mptcp_recvmsg() [0]. When receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not removed from the sk_receive_queue. This causes sk_wait_data() to always find available data and never perform actual waiting, leading to a soft lockup. Fix this by adding a \u0027last\u0027 parameter to track the last peeked skb. This allows sk_wait_data() to make informed waiting decisions and prevent infinite loops when MSG_PEEK is used. [0]: watchdog: BUG: soft lockup - CPU#2 stuck for 156s! [server:1963] Modules linked in: CPU: 2 UID: 0 PID: 1963 Comm: server Not tainted 6.19.0-rc8 #61 PREEMPT(none) Hardware name: QEMU Standard PC (i440FX \u002B PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:sk_wait_data\u002B0x15/0x190 Code: 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 56 41 55 41 54 49 89 f4 55 48 89 d5 53 48 89 fb \u003C48\u003E 83 ec 30 65 48 8b 05 17 a4 6b 01 48 89 44 24 28 31 c0 65 48 8b RSP: 0018:ffffc90000603ca0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888102bf0800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffc90000603d18 RDI: ffff888102bf0800 RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000101 R10: 0000000000000000 R11: 0000000000000075 R12: ffffc90000603d18 R13: ffff888102bf0800 R14: ffff888102bf0800 R15: 0000000000000000 FS: 00007f6e38b8c4c0(0000) GS:ffff8881b877e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055aa7bff1680 CR3: 0000000105cbe000 CR4: 00000000000006f0 Call Trace: \u003CTASK\u003E mptcp_recvmsg\u002B0x547/0x8c0 net/mptcp/protocol.c:2329 inet_recvmsg\u002B0x11f/0x130 net/ipv4/af_inet.c:891 sock_recvmsg\u002B0x94/0xc0 net/socket.c:1100 __sys_recvfrom\u002B0xb2/0x130 net/socket.c:2256 __x64_sys_recvfrom\u002B0x1f/0x30 net/socket.c:2267 do_syscall_64\u002B0x59/0x2d0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe\u002B0x76/0x7e arch/x86/entry/entry_64.S:131 RIP: 0033:0x7f6e386a4a1d Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8d 05 f1 de 2c 00 41 89 ca 8b 00 85 c0 75 20 45 31 c9 45 31 c0 b8 2d 00 00 00 0f 05 \u003C48\u003E 3d 00 f0 ff ff 77 6b f3 c3 66 0f 1f 84 00 00 00 00 00 41 56 41 RSP: 002b:00007ffc3c4bb078 EFLAGS: 00000246 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 000000000000861e RCX: 00007f6e386a4a1d RDX: 00000000000003ff RSI: 00007ffc3c4bb150 RDI: 0000000000000004 RBP: 00007ffc3c4bb570 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000103 R11: 0000000000000246 R12: 00005605dbc00be0 R13: 00007ffc3c4bb650 R14: 0000000000000000 R15: 0000000000000000 \u003C/TASK\u003E", "published": "2026-05-01T15:16:47Z", "severity": "Moderate", "cvss": 7.5, "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "cwe": "Improper Locking", "epss": 0.00329, "epssPercentile": 0.2622, "priority": "High", "priorityTier": 3, "exploited": false, "vendorExploited": false, "disclosed": false, "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43029", "fixes": [ { "platform": "linux", "product": "bpftool6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "bpftool6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel-livepatch-6.18.25-52.107", "release": "amzn 2023", "fixedVersion": "1:1.0-0.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-aarch64", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-x86_64", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-headers", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra-common", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-tools", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-tools-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-tools-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "linux", "release": "Debian 14", "fixedVersion": "6.19.12-1", "fix": "DEBIAN-CVE-2026-43029", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-43029", "released": "2026-05-15T16:01:09Z" }, { "platform": "linux", "product": "perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "python3-perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "python3-perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.25-52.107.amzn2023", "fix": "ALAS2023-2026-1746", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1746", "released": "2026-05-25T09:00:00Z" } ], "noFixYet": [], "dataAsOf": "2026-11-08T19:12:23Z", "attribution": { "text": "Data: Patchblox Patch Radar", "url": "https://patchblox.com/security/patch-radar", "terms": "https://patchblox.com/security/patch-radar/use-the-data" } }