{
  "threat_severity" : "Moderate",
  "public_date" : "2025-02-26T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: tcp: tcp_rtx_synack() can be called from process context",
    "id" : "2348024",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2348024"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\ntcp: tcp_rtx_synack() can be called from process context\nLaurent reported the enclosed report [1]\nThis bug triggers with following coditions:\n0) Kernel built with CONFIG_DEBUG_PREEMPT=y\n1) A new passive FastOpen TCP socket is created.\nThis FO socket waits for an ACK coming from client to be a complete\nESTABLISHED one.\n2) A socket operation on this socket goes through lock_sock()\nrelease_sock() dance.\n3) While the socket is owned by the user in step 2),\na retransmit of the SYN is received and stored in socket backlog.\n4) At release_sock() time, the socket backlog is processed while\nin process context.\n5) A SYNACK packet is cooked in response of the SYN retransmit.\n6) -> tcp_rtx_synack() is called in process context.\nBefore blamed commit, tcp_rtx_synack() was always called from BH handler,\nfrom a timer handler.\nFix this by using TCP_INC_STATS() & NET_INC_STATS()\nwhich do not assume caller is in non preemptible context.\n[1]\nBUG: using __this_cpu_add() in preemptible [00000000] code: epollpep/2180\ncaller is tcp_rtx_synack.part.0+0x36/0xc0\nCPU: 10 PID: 2180 Comm: epollpep Tainted: G           OE     5.16.0-0.bpo.4-amd64 #1  Debian 5.16.12-1~bpo11+1\nHardware name: Supermicro SYS-5039MC-H8TRF/X11SCD-F, BIOS 1.7 11/23/2021\nCall Trace:\n<TASK>\ndump_stack_lvl+0x48/0x5e\ncheck_preemption_disabled+0xde/0xe0\ntcp_rtx_synack.part.0+0x36/0xc0\ntcp_rtx_synack+0x8d/0xa0\n? kmem_cache_alloc+0x2e0/0x3e0\n? apparmor_file_alloc_security+0x3b/0x1f0\ninet_rtx_syn_ack+0x16/0x30\ntcp_check_req+0x367/0x610\ntcp_rcv_state_process+0x91/0xf60\n? get_nohz_timer_target+0x18/0x1a0\n? lock_timer_base+0x61/0x80\n? preempt_count_add+0x68/0xa0\ntcp_v4_do_rcv+0xbd/0x270\n__release_sock+0x6d/0xb0\nrelease_sock+0x2b/0x90\nsock_setsockopt+0x138/0x1140\n? __sys_getsockname+0x7e/0xc0\n? aa_sk_perm+0x3e/0x1a0\n__sys_setsockopt+0x198/0x1e0\n__x64_sys_setsockopt+0x21/0x30\ndo_syscall_64+0x38/0xc0\nentry_SYSCALL_64_after_hwframe+0x44/0xae" ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2023-05-16T00:00:00Z",
    "advisory" : "RHSA-2023:2951",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-477.10.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2023-05-09T00:00:00Z",
    "advisory" : "RHSA-2023:2458",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-284.11.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2023-05-09T00:00:00Z",
    "advisory" : "RHSA-2023:2458",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-284.11.1.el9_2"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2022-49372\nhttps://nvd.nist.gov/vuln/detail/CVE-2022-49372\nhttps://lore.kernel.org/linux-cve-announce/2025022646-CVE-2022-49372-45e1@gregkh/T" ],
  "name" : "CVE-2022-49372",
  "csaw" : false
}