{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-4442",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: add sanity tests to TCP_QUEUE_SEQ\n\nQingyu Li reported a syzkaller bug where the repro\nchanges RCV SEQ _after_ restoring data in the receive queue.\n\nmprotect(0x4aa000, 12288, PROT_READ)    = 0\nmmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000\nmmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000\nmmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000\nsocket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3\nsetsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0\nconnect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, \"::1\", &sin6_addr), sin6_scope_id=0}, 28) = 0\nsetsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0\nsendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"0x0000000000000003\\0\\0\", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20\nsetsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0\nsetsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0\nrecvfrom(3, NULL, 20, 0, NULL, NULL)    = -1 ECONNRESET (Connection reset by peer)\n\nsyslog shows:\n[  111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0\n[  111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0\n\nThis should not be allowed. TCP_QUEUE_SEQ should only be used\nwhen queues are empty.\n\nThis patch fixes this case, and the tx path as well."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "ee9952831cfd",
                                            "version_value": "319f460237fc"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "3.5",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "3.5",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "4.19.181",
                                                        "lessThanOrEqual": "4.19.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.4.106",
                                                        "lessThanOrEqual": "5.4.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.10.24",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.11.7",
                                                        "lessThanOrEqual": "5.11.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.12",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
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                                                "defaultStatus": "affected"
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    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a"
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                "url": "https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6"
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                "url": "https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e"
            },
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                "name": "https://git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2"
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                "url": "https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d"
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