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Fencer Vulns
medium 5.5

CVE-2024-44935 json

sctp: Fix null-ptr-deref in reuseport_add_sock().

published 2024-08-26 2 y ago modified 2026-10-15 25 d ago also EUVD-2024-41147

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 13%
public exploits
0
none known

Summary

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

sctp: Fix null-ptr-deref in reuseport_add_sock().

syzbot reported a null-ptr-deref while accessing sk2->sk_reuseport_cb in reuseport_add_sock(). [0]

The repro first creates a listener with SO_REUSEPORT. Then, it creates another listener on the same port and concurrently closes the first listener.

The second listen() calls reuseport_add_sock() with the first listener as sk2, where sk2->sk_reuseport_cb is not expected to be cleared concurrently, but the close() does clear it by reuseport_detach_sock().

The problem is SCTP does not properly synchronise reuseport_alloc(), reuseport_add_sock(), and reuseport_detach_sock().

The caller of reuseport_alloc() and reuseport_{add,detach}_sock() must provide synchronisation for sockets that are classified into the same reuseport group.

Otherwise, such sockets form multiple identical reuseport groups, and all groups except one would be silently dead.

1. Two sockets call listen() concurrently 2. No socket in the same group found in sctp_ep_hashtable[] 3. Two sockets call reuseport_alloc() and form two reuseport groups 4. Only one group hit first in __sctp_rcv_lookup_endpoint() receives incoming packets

Also, the reported null-ptr-deref could occur.

TCP/UDP guarantees that would not happen by holding the hash bucket lock.

Let's apply the locking strategy to __sctp_hash_endpoint() and __sctp_unhash_endpoint().

[0]: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 UID: 0 PID: 10230 Comm: syz-executor119 Not tainted 6.10.0-syzkaller-12585-g301927d2d2eb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:reuseport_add_sock+0x27e/0x5e0 net/core/sock_reuseport.c:350 Code: 00 0f b7 5d 00 bf 01 00 00 00 89 de e8 1b a4 ff f7 83 fb 01 0f 85 a3 01 00 00 e8 6d a0 ff f7 49 8d 7e 12 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 4b 02 00 00 41 0f b7 5e 12 49 8d 7e 14 RSP: 0018:ffffc9000b947c98 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff8880252ddf98 RCX: ffff888079478000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000012 RBP: 0000000000000001 R08: ffffffff8993e18d R09: 1ffffffff1fef385 R10: dffffc0000000000 R11: fffffbfff1fef386 R12: ffff8880252ddac0 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f24e45b96c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcced5f7b8 CR3: 00000000241be000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __sctp_hash_endpoint net/sctp/input.c:762 [inline] sctp_hash_endpoint+0x52a/0x600 net/sctp/input.c:790 sctp_listen_start net/sctp/socket.c:8570 [inline] sctp_inet_listen+0x767/0xa20 net/sctp/socket.c:8625 __sys_listen_socket net/socket.c:1883 [inline] __sys_listen+0x1b7/0x230 net/socket.c:1894 __do_sys_listen net/socket.c:1902 [inline] __se_sys_listen net/socket.c:1900 [inline] __x64_sys_listen+0x5a/0x70 net/socket.c:1900 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f24e46039b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24e45b9228 EFLAGS: 00000246 ORIG_RAX: 0000000000000032 RAX: ffffffffffffffda RBX: 00007f24e468e428 RCX: 00007f24e46039b9 RDX: 00007f24e46039b9 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f24e468e420 R08: 00007f24e45b96c0 R09: 00007f24e45b96c0 R10: 00007f24e45b96c0 R11: 0000000000000246 R12: 00007f24e468e42c R13: ---truncated---

Patch / fix

  • Linux Linux 5.4.282, 5.10.224, 5.15.165, 6.1.105, 6.6.46, 6.10.5, 6.11
  • Siemens RUGGEDCOM RST2428P V3.1
  • Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family V3.1
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem V1.1.1
  • linux Debian 12 6.1.106-1
  • linux Debian 14, Debian 13 6.10.6-1

debian advisories DEBIAN-CVE-2024-44935

  • linux Ubuntu 20.04 LTS 5.4.0-200.220
  • linux Ubuntu 22.04 LTS 5.15.0-125.135
  • linux Ubuntu 24.04 LTS 6.8.0-50.51
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1135.145
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1072.78
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1020.22
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1139.148
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1071.79

ubuntu advisories UBUNTU-CVE-2024-44935

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-rt RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.27.1.rt7.368.el8_10

red hat advisories RHSA-2025:2270RHSA-2024:8870RHSA-2024:8856

  • kernel-rt Linux Micro 6.0 6.4.0-11.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-11.1
  • kernel-livepatch-MICRO-6-0-RT_Update_3 Linux Micro 6.0 1-1.2
  • kernel-source Linux Micro 6.0 6.4.0-20.1
  • kernel-default Linux Micro 6.0 6.4.0-20.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-20.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_3 Linux Micro 6.0 1-1.2

suse advisories SUSE-SU-2025:20077-1SUSE-SU-2025:20073-1SUSE-SU-2024:3592-1SUSE-SU-2024:3587-1SUSE-SU-2024:3569-1SUSE-SU-2024:3564-1

  • kernel AlmaLinux 8 4.18.0-553.27.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.27.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.27.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.27.1.el8_10

almalinux advisories ALSA-2024:8856ALSA-2024:8870

  • kernel-rt Rocky Linux 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel Rocky Linux 8 4.18.0-553.27.1.el8_10

rocky linux advisories RLSA-2024:8870RLSA-2024:8856

  • kernel CBL-Mariner 2.0 5.15.167.1-1

azure linux advisories AZL-48246

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2024-44935 updated cvss 5.5

kernel: sctp: Fix null-ptr-deref in reuseport_add_sock().

  • 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: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.57.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.57.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.57.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.57.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.57.1.el9_4 Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.57.1.el9_4, perf 5.14.0-427.57.1.el9_4, rtla 5.14.0-427.57.1.el9_4, kernel-devel-matched 5.14.0-427.57.1.el9_4, kernel-64k-devel-matched 5.14.0-427.57.1.el9_4, kernel-debug-devel-matched 5.14.0-427.57.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:2270
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.27.1.el8_10, kernel 4.18.0-553.27.1.el8_10, bpftool 4.18.0-553.27.1.el8_10, kernel-core 4.18.0-553.27.1.el8_10, kernel-tools 4.18.0-553.27.1.el8_10, python3-perf 4.18.0-553.27.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:8856
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.57.1.el9_4, kernel 5.14.0-427.57.1.el9_4, kernel-64k 5.14.0-427.57.1.el9_4, kernel-core 5.14.0-427.57.1.el9_4, kernel-tools 5.14.0-427.57.1.el9_4, python3-perf 5.14.0-427.57.1.el9_4, +28 more
    fixed: vendor fix RHSA-2025:2270
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.27.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.27.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.27.1.el8_10
    fixed: vendor fix RHSA-2024:8856
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-kvm 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-core 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-modules 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-kvm 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-core 4.18.0-553.27.1.rt7.368.el8_10, +4 more
    fixed: vendor fix RHSA-2024:8870
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.57.1.el9_4, kernel-rt-core 5.14.0-427.57.1.el9_4, kernel-rt-modules 5.14.0-427.57.1.el9_4, kernel-rt-debug-core 5.14.0-427.57.1.el9_4, kernel-rt-modules-core 5.14.0-427.57.1.el9_4, kernel-rt-debug-modules 5.14.0-427.57.1.el9_4, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.57.1.el9_4, kernel-rt-kvm 5.14.0-427.57.1.el9_4, kernel-rt-core 5.14.0-427.57.1.el9_4, kernel-rt-modules 5.14.0-427.57.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.57.1.el9_4, kernel-rt-debug-core 5.14.0-427.57.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:2270
show 1 more
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-core 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-modules 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-core 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-modules 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-modules-extra 4.18.0-553.27.1.rt7.368.el8_10, +2 more
    fixed: vendor fix RHSA-2024:8870

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 5.5

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-25-226-07 updated

Siemens Third-Party Components in SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 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-25-226-15 updated cvss 5.5

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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% 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 TM MFP - GNU/Linux subsystem

Classification

Weakness
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.