{"api_version":"1","generated_at":"2026-05-02T14:07:01+00:00","cve":"CVE-2026-43029","urls":{"html":"https://cve.report/CVE-2026-43029","api":"https://cve.report/api/cve/CVE-2026-43029.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43029","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43029"},"summary":{"title":"mptcp: fix soft lockup in mptcp_recvmsg()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix soft lockup in mptcp_recvmsg()\n\nsyzbot reported a soft lockup in mptcp_recvmsg() [0].\n\nWhen receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not\nremoved from the sk_receive_queue. This causes sk_wait_data() to always\nfind available data and never perform actual waiting, leading to a soft\nlockup.\n\nFix this by adding a 'last' parameter to track the last peeked skb.\nThis allows sk_wait_data() to make informed waiting decisions and prevent\ninfinite loops when MSG_PEEK is used.\n\n[0]:\nwatchdog: BUG: soft lockup - CPU#2 stuck for 156s! [server:1963]\nModules linked in:\nCPU: 2 UID: 0 PID: 1963 Comm: server Not tainted 6.19.0-rc8 #61 PREEMPT(none)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nRIP: 0010:sk_wait_data+0x15/0x190\nCode: 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 <48> 83 ec 30 65 48 8b 05 17 a4 6b 01 48 89 44 24 28 31 c0 65 48 8b\nRSP: 0018:ffffc90000603ca0 EFLAGS: 00000246\nRAX: 0000000000000000 RBX: ffff888102bf0800 RCX: 0000000000000001\nRDX: 0000000000000000 RSI: ffffc90000603d18 RDI: ffff888102bf0800\nRBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000101\nR10: 0000000000000000 R11: 0000000000000075 R12: ffffc90000603d18\nR13: ffff888102bf0800 R14: ffff888102bf0800 R15: 0000000000000000\nFS:  00007f6e38b8c4c0(0000) GS:ffff8881b877e000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000055aa7bff1680 CR3: 0000000105cbe000 CR4: 00000000000006f0\nCall Trace:\n <TASK>\n mptcp_recvmsg+0x547/0x8c0 net/mptcp/protocol.c:2329\n inet_recvmsg+0x11f/0x130 net/ipv4/af_inet.c:891\n sock_recvmsg+0x94/0xc0 net/socket.c:1100\n __sys_recvfrom+0xb2/0x130 net/socket.c:2256\n __x64_sys_recvfrom+0x1f/0x30 net/socket.c:2267\n do_syscall_64+0x59/0x2d0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e arch/x86/entry/entry_64.S:131\nRIP: 0033:0x7f6e386a4a1d\nCode: 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 <48> 3d 00 f0 ff ff 77 6b f3 c3 66 0f 1f 84 00 00 00 00 00 41 56 41\nRSP: 002b:00007ffc3c4bb078 EFLAGS: 00000246 ORIG_RAX: 000000000000002d\nRAX: ffffffffffffffda RBX: 000000000000861e RCX: 00007f6e386a4a1d\nRDX: 00000000000003ff RSI: 00007ffc3c4bb150 RDI: 0000000000000004\nRBP: 00007ffc3c4bb570 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000103 R11: 0000000000000246 R12: 00005605dbc00be0\nR13: 00007ffc3c4bb650 R14: 0000000000000000 R15: 0000000000000000\n </TASK>","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-01 15:16:47","updated_at":"2026-05-01 15:24:14"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/5dd8025a49c268ab6b94d978532af3ad341132a7","name":"https://git.kernel.org/stable/c/5dd8025a49c268ab6b94d978532af3ad341132a7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/58b58b9ba89c43914eea90c18928e51852d10c24","name":"https://git.kernel.org/stable/c/58b58b9ba89c43914eea90c18928e51852d10c24","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/de3c248d1b69eaefa2d5b3da4005936dcf590f1b","name":"https://git.kernel.org/stable/c/de3c248d1b69eaefa2d5b3da4005936dcf590f1b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43029","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43029","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8e04ce45a8db7a080220e86e249198fa676b83dc 58b58b9ba89c43914eea90c18928e51852d10c24 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8e04ce45a8db7a080220e86e249198fa676b83dc de3c248d1b69eaefa2d5b3da4005936dcf590f1b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8e04ce45a8db7a080220e86e249198fa676b83dc 5dd8025a49c268ab6b94d978532af3ad341132a7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 49888b3b457b801282b44c246d289c56e2f2a55b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0206a9341e652167c610dcd79f3d4e9e8153984c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7d6d10eee01edc9c20850ea75cf8273dc1170921 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.22 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.12 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/mptcp/protocol.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"58b58b9ba89c43914eea90c18928e51852d10c24","status":"affected","version":"8e04ce45a8db7a080220e86e249198fa676b83dc","versionType":"git"},{"lessThan":"de3c248d1b69eaefa2d5b3da4005936dcf590f1b","status":"affected","version":"8e04ce45a8db7a080220e86e249198fa676b83dc","versionType":"git"},{"lessThan":"5dd8025a49c268ab6b94d978532af3ad341132a7","status":"affected","version":"8e04ce45a8db7a080220e86e249198fa676b83dc","versionType":"git"},{"status":"affected","version":"49888b3b457b801282b44c246d289c56e2f2a55b","versionType":"git"},{"status":"affected","version":"0206a9341e652167c610dcd79f3d4e9e8153984c","versionType":"git"},{"status":"affected","version":"7d6d10eee01edc9c20850ea75cf8273dc1170921","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/mptcp/protocol.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.18"},{"lessThan":"6.18","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.22","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.12","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.22","versionStartIncluding":"6.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.12","versionStartIncluding":"6.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"6.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.117","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.59","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17.8","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix soft lockup in mptcp_recvmsg()\n\nsyzbot reported a soft lockup in mptcp_recvmsg() [0].\n\nWhen receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not\nremoved from the sk_receive_queue. This causes sk_wait_data() to always\nfind available data and never perform actual waiting, leading to a soft\nlockup.\n\nFix this by adding a 'last' parameter to track the last peeked skb.\nThis allows sk_wait_data() to make informed waiting decisions and prevent\ninfinite loops when MSG_PEEK is used.\n\n[0]:\nwatchdog: BUG: soft lockup - CPU#2 stuck for 156s! [server:1963]\nModules linked in:\nCPU: 2 UID: 0 PID: 1963 Comm: server Not tainted 6.19.0-rc8 #61 PREEMPT(none)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nRIP: 0010:sk_wait_data+0x15/0x190\nCode: 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 <48> 83 ec 30 65 48 8b 05 17 a4 6b 01 48 89 44 24 28 31 c0 65 48 8b\nRSP: 0018:ffffc90000603ca0 EFLAGS: 00000246\nRAX: 0000000000000000 RBX: ffff888102bf0800 RCX: 0000000000000001\nRDX: 0000000000000000 RSI: ffffc90000603d18 RDI: ffff888102bf0800\nRBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000101\nR10: 0000000000000000 R11: 0000000000000075 R12: ffffc90000603d18\nR13: ffff888102bf0800 R14: ffff888102bf0800 R15: 0000000000000000\nFS:  00007f6e38b8c4c0(0000) GS:ffff8881b877e000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000055aa7bff1680 CR3: 0000000105cbe000 CR4: 00000000000006f0\nCall Trace:\n <TASK>\n mptcp_recvmsg+0x547/0x8c0 net/mptcp/protocol.c:2329\n inet_recvmsg+0x11f/0x130 net/ipv4/af_inet.c:891\n sock_recvmsg+0x94/0xc0 net/socket.c:1100\n __sys_recvfrom+0xb2/0x130 net/socket.c:2256\n __x64_sys_recvfrom+0x1f/0x30 net/socket.c:2267\n do_syscall_64+0x59/0x2d0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e arch/x86/entry/entry_64.S:131\nRIP: 0033:0x7f6e386a4a1d\nCode: 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 <48> 3d 00 f0 ff ff 77 6b f3 c3 66 0f 1f 84 00 00 00 00 00 41 56 41\nRSP: 002b:00007ffc3c4bb078 EFLAGS: 00000246 ORIG_RAX: 000000000000002d\nRAX: ffffffffffffffda RBX: 000000000000861e RCX: 00007f6e386a4a1d\nRDX: 00000000000003ff RSI: 00007ffc3c4bb150 RDI: 0000000000000004\nRBP: 00007ffc3c4bb570 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000103 R11: 0000000000000246 R12: 00005605dbc00be0\nR13: 00007ffc3c4bb650 R14: 0000000000000000 R15: 0000000000000000\n </TASK>"}],"providerMetadata":{"dateUpdated":"2026-05-01T14:15:29.885Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/58b58b9ba89c43914eea90c18928e51852d10c24"},{"url":"https://git.kernel.org/stable/c/de3c248d1b69eaefa2d5b3da4005936dcf590f1b"},{"url":"https://git.kernel.org/stable/c/5dd8025a49c268ab6b94d978532af3ad341132a7"}],"title":"mptcp: fix soft lockup in mptcp_recvmsg()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43029","datePublished":"2026-05-01T14:15:29.885Z","dateReserved":"2026-05-01T14:12:55.976Z","dateUpdated":"2026-05-01T14:15:29.885Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-01 15:16:47","lastModifiedDate":"2026-05-01 15:24:14","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43029","Ordinal":"1","Title":"mptcp: fix soft lockup in mptcp_recvmsg()","CVE":"CVE-2026-43029","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43029","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix soft lockup in mptcp_recvmsg()\n\nsyzbot reported a soft lockup in mptcp_recvmsg() [0].\n\nWhen receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not\nremoved from the sk_receive_queue. This causes sk_wait_data() to always\nfind available data and never perform actual waiting, leading to a soft\nlockup.\n\nFix this by adding a 'last' parameter to track the last peeked skb.\nThis allows sk_wait_data() to make informed waiting decisions and prevent\ninfinite loops when MSG_PEEK is used.\n\n[0]:\nwatchdog: BUG: soft lockup - CPU#2 stuck for 156s! [server:1963]\nModules linked in:\nCPU: 2 UID: 0 PID: 1963 Comm: server Not tainted 6.19.0-rc8 #61 PREEMPT(none)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nRIP: 0010:sk_wait_data+0x15/0x190\nCode: 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 <48> 83 ec 30 65 48 8b 05 17 a4 6b 01 48 89 44 24 28 31 c0 65 48 8b\nRSP: 0018:ffffc90000603ca0 EFLAGS: 00000246\nRAX: 0000000000000000 RBX: ffff888102bf0800 RCX: 0000000000000001\nRDX: 0000000000000000 RSI: ffffc90000603d18 RDI: ffff888102bf0800\nRBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000101\nR10: 0000000000000000 R11: 0000000000000075 R12: ffffc90000603d18\nR13: ffff888102bf0800 R14: ffff888102bf0800 R15: 0000000000000000\nFS:  00007f6e38b8c4c0(0000) GS:ffff8881b877e000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000055aa7bff1680 CR3: 0000000105cbe000 CR4: 00000000000006f0\nCall Trace:\n <TASK>\n mptcp_recvmsg+0x547/0x8c0 net/mptcp/protocol.c:2329\n inet_recvmsg+0x11f/0x130 net/ipv4/af_inet.c:891\n sock_recvmsg+0x94/0xc0 net/socket.c:1100\n __sys_recvfrom+0xb2/0x130 net/socket.c:2256\n __x64_sys_recvfrom+0x1f/0x30 net/socket.c:2267\n do_syscall_64+0x59/0x2d0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e arch/x86/entry/entry_64.S:131\nRIP: 0033:0x7f6e386a4a1d\nCode: 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 <48> 3d 00 f0 ff ff 77 6b f3 c3 66 0f 1f 84 00 00 00 00 00 41 56 41\nRSP: 002b:00007ffc3c4bb078 EFLAGS: 00000246 ORIG_RAX: 000000000000002d\nRAX: ffffffffffffffda RBX: 000000000000861e RCX: 00007f6e386a4a1d\nRDX: 00000000000003ff RSI: 00007ffc3c4bb150 RDI: 0000000000000004\nRBP: 00007ffc3c4bb570 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000103 R11: 0000000000000246 R12: 00005605dbc00be0\nR13: 00007ffc3c4bb650 R14: 0000000000000000 R15: 0000000000000000\n </TASK>","Type":"Description","Title":"mptcp: fix soft lockup in mptcp_recvmsg()"}]}}}