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Fencer Vulns
medium 5.5

CVE-2024-37356 json

tcp: Fix shift-out-of-bounds in dctcp_update_alpha().

published 2024-06-21 2 y ago modified 2026-10-15 25 d ago also EUVD-2024-36980

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

tcp: Fix shift-out-of-bounds in dctcp_update_alpha().

In dctcp_update_alpha(), we use a module parameter dctcp_shift_g as follows:

alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g); ... delivered_ce <<= (10 - dctcp_shift_g);

It seems syzkaller started fuzzing module parameters and triggered shift-out-of-bounds [0] by setting 100 to dctcp_shift_g:

memcpy((void*)0x20000080, "/sys/module/tcp_dctcp/parameters/dctcp_shift_g\000", 47); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul, /*flags=*/2ul, /*mode=*/0ul); memcpy((void*)0x20000000, "100\000", 4); syscall(__NR_write, /*fd=*/r[0], /*val=*/0x20000000ul, /*len=*/4ul);

Let's limit the max value of dctcp_shift_g by param_set_uint_minmax().

With this patch:

# echo 10 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g # cat /sys/module/tcp_dctcp/parameters/dctcp_shift_g 10 # echo 11 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g -bash: echo: write error: Invalid argument

[0]: UBSAN: shift-out-of-bounds in net/ipv4/tcp_dctcp.c:143:12 shift exponent 100 is too large for 32-bit type 'u32' (aka 'unsigned int') CPU: 0 PID: 8083 Comm: syz-executor345 Not tainted 6.9.0-05151-g1b294a1f3561 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_shift_out_of_bounds+0x346/0x3a0 lib/ubsan.c:468 dctcp_update_alpha+0x540/0x570 net/ipv4/tcp_dctcp.c:143 tcp_in_ack_event net/ipv4/tcp_input.c:3802 [inline] tcp_ack+0x17b1/0x3bc0 net/ipv4/tcp_input.c:3948 tcp_rcv_state_process+0x57a/0x2290 net/ipv4/tcp_input.c:6711 tcp_v4_do_rcv+0x764/0xc40 net/ipv4/tcp_ipv4.c:1937 sk_backlog_rcv include/net/sock.h:1106 [inline] __release_sock+0x20f/0x350 net/core/sock.c:2983 release_sock+0x61/0x1f0 net/core/sock.c:3549 mptcp_subflow_shutdown+0x3d0/0x620 net/mptcp/protocol.c:2907 mptcp_check_send_data_fin+0x225/0x410 net/mptcp/protocol.c:2976 __mptcp_close+0x238/0xad0 net/mptcp/protocol.c:3072 mptcp_close+0x2a/0x1a0 net/mptcp/protocol.c:3127 inet_release+0x190/0x1f0 net/ipv4/af_inet.c:437 __sock_release net/socket.c:659 [inline] sock_close+0xc0/0x240 net/socket.c:1421 __fput+0x41b/0x890 fs/file_table.c:422 task_work_run+0x23b/0x300 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x9c8/0x2540 kernel/exit.c:878 do_group_exit+0x201/0x2b0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xe4/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x67/0x6f RIP: 0033:0x7f6c2b5005b6 Code: Unable to access opcode bytes at 0x7f6c2b50058c. RSP: 002b:00007ffe883eb948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6c2b5862f0 RCX: 00007f6c2b5005b6 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 0000000000000001 R08: 00000000000000e7 R09: ffffffffffffffc0 R10: 0000000000000006 R11: 0000000000000246 R12: 00007f6c2b5862f0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 </TASK>

Patch / fix

  • Linux Linux 4.19.316, 5.4.278, 5.10.219, 5.15.161, 6.1.93, 6.6.33, 6.9.4, 6.10
  • Siemens RUGGEDCOM RST2428P V3.1
  • Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family V3.1
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem V1.1.1
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • linux Debian 12 6.1.94-1
  • linux Debian 14, Debian 13 6.9.7-1

debian advisories DEBIAN-CVE-2024-37356

  • linux Ubuntu 20.04 LTS 5.4.0-192.212
  • linux Ubuntu 22.04 LTS 5.15.0-121.131
  • linux Ubuntu 24.04 LTS 6.8.0-44.44
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1130.140
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1069.75
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1015.16
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1134.143
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1068.76

ubuntu advisories UBUNTU-CVE-2024-37356

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 8 4.18.0-553.22.1.el8_10
  • perf RHEL 8 4.18.0-553.22.1.el8_10
  • bpftool RHEL 8 4.18.0-553.22.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.22.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.22.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.22.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.22.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.22.1.el8_10

red hat advisories RHSA-2024:10773RHSA-2024:10772RHSA-2024:7000RHSA-2024:7001RHSA-2024:6206RHSA-2024:5363

  • kernel AlmaLinux 8 4.18.0-553.22.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.22.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.22.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.22.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.22.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.22.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.22.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.22.1.el8_10

almalinux advisories ALSA-2024:7000ALSA-2024:7001ALSA-2024:5363

  • kernel Rocky Linux 8 4.18.0-553.22.1.el8_10
  • kernel-rt Rocky Linux 8 4.18.0-553.22.1.rt7.363.el8_10
  • kernel Rocky Linux 9 5.14.0-427.31.1.el9_4

rocky linux advisories RLSA-2024:7000RLSA-2024:7001RLSA-2024:5363

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-37356 updated cvss 6.6

kernel: tcp: Fix shift-out-of-bounds in dctcp_update_alpha().

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: no fix available
  • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.70.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.70.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.70.1.el8_8
    fixed: vendor fix RHSA-2024:6206
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.95.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.95.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.95.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.95.1.el9_2
    fixed: vendor fix RHSA-2024:10772
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.31.1.el9_4, perf 5.14.0-427.31.1.el9_4, rtla 5.14.0-427.31.1.el9_4, kernel-devel-matched 5.14.0-427.31.1.el9_4, kernel-64k-devel-matched 5.14.0-427.31.1.el9_4, kernel-debug-devel-matched 5.14.0-427.31.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:5363
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.95.1.el9_2, rtla 5.14.0-284.95.1.el9_2, kernel-devel-matched 5.14.0-284.95.1.el9_2, kernel-64k-devel-matched 5.14.0-284.95.1.el9_2, kernel-debug-devel-matched 5.14.0-284.95.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.95.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:10772
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.22.1.el8_10, kernel 4.18.0-553.22.1.el8_10, bpftool 4.18.0-553.22.1.el8_10, kernel-core 4.18.0-553.22.1.el8_10, kernel-tools 4.18.0-553.22.1.el8_10, python3-perf 4.18.0-553.22.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:7000
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.31.1.el9_4, kernel 5.14.0-427.31.1.el9_4, kernel-64k 5.14.0-427.31.1.el9_4, kernel-core 5.14.0-427.31.1.el9_4, kernel-tools 5.14.0-427.31.1.el9_4, python3-perf 5.14.0-427.31.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:5363
show 11 more
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.70.1.el8_8, kernel 4.18.0-477.70.1.el8_8, bpftool 4.18.0-477.70.1.el8_8, kernel-core 4.18.0-477.70.1.el8_8, kernel-tools 4.18.0-477.70.1.el8_8, python3-perf 4.18.0-477.70.1.el8_8, +15 more
    fixed: vendor fix RHSA-2024:6206
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.95.1.el9_2, kernel 5.14.0-284.95.1.el9_2, kernel-64k 5.14.0-284.95.1.el9_2, kernel-core 5.14.0-284.95.1.el9_2, kernel-tools 5.14.0-284.95.1.el9_2, python3-perf 5.14.0-284.95.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:10772
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.22.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.22.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.22.1.el8_10
    fixed: vendor fix RHSA-2024:7000
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.31.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.31.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.31.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.31.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.31.1.el9_4
    fixed: vendor fix RHSA-2024:5363
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-kvm 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-core 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-modules 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-debug-kvm 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-debug-core 4.18.0-553.22.1.rt7.363.el8_10, +4 more
    fixed: vendor fix RHSA-2024:7001
  • Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.31.1.el9_4, kernel-rt-kvm 5.14.0-427.31.1.el9_4, kernel-rt-core 5.14.0-427.31.1.el9_4, kernel-rt-modules 5.14.0-427.31.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.31.1.el9_4, kernel-rt-debug-core 5.14.0-427.31.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:5363
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-core 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-modules 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-debug-core 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-modules-core 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-debug-modules 5.14.0-284.95.1.rt14.380.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-kvm 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-core 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-modules 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-debug-kvm 5.14.0-284.95.1.rt14.380.el9_2, kernel-rt-debug-core 5.14.0-284.95.1.rt14.380.el9_2, +6 more
    fixed: vendor fix RHSA-2024:10773
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-core 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-modules 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-debug-core 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-debug-modules 4.18.0-553.22.1.rt7.363.el8_10, kernel-rt-modules-extra 4.18.0-553.22.1.rt7.363.el8_10, +2 more
    fixed: vendor fix RHSA-2024:7001
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.31.1.el9_4, kernel-rt-core 5.14.0-427.31.1.el9_4, kernel-rt-modules 5.14.0-427.31.1.el9_4, kernel-rt-debug-core 5.14.0-427.31.1.el9_4, kernel-rt-modules-core 5.14.0-427.31.1.el9_4, kernel-rt-debug-modules 5.14.0-427.31.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:5363
  • Red Hat OpenShift AI 8 rhoai/odh-rhel8-operator v2.13.1-2, rhoai/odh-dashboard-rhel8 v2.13.1-1, rhoai/odh-modelmesh-rhel8 v2.13.1-1, rhoai/odh-operator-bundle v2.13.1-2, rhoai/odh-rhel8-operator v2.14.0-24, rhoai/odh-dashboard-rhel8 v2.14.0-11, +56 more
    fixed: vendor fix RHBA-2024:8413
  • Red Hat Enterprise Linux AppStream (v. 9) kernel-headers 5.14.0-427.31.1.el9_4 Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-doc 5.14.0-284.95.1.el9_2 Red Hat Enterprise Linux CRB (v. 9) kernel-cross-headers 5.14.0-427.31.1.el9_4
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-24-102-01 updated cvss 6.6

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-25-226-15 updated cvss 6.6

Siemens SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) < 3.1 Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family < 3.1
    affected: fixed in V3.1 support.industry.siemens.com
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
    not affected

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-23-348-10 updated cvss 6.6

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux
  • Siemens RUGGEDCOM RST2428P
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
  • Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.