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Fencer Vulns
high 7.8

CVE-2024-40958 json

netns: Make get_net_ns() handle zero refcount net

published 2024-07-12 2 y ago modified 2026-10-15 25 d ago also EUVD-2024-38755

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

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

netns: Make get_net_ns() handle zero refcount net

Syzkaller hit a warning: refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 7890 at lib/refcount.c:25 refcount_warn_saturate+0xdf/0x1d0 Modules linked in: CPU: 3 PID: 7890 Comm: tun Not tainted 6.10.0-rc3-00100-gcaa4f9578aba-dirty #310 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:refcount_warn_saturate+0xdf/0x1d0 Code: 41 49 04 31 ff 89 de e8 9f 1e cd fe 84 db 75 9c e8 76 26 cd fe c6 05 b6 41 49 04 01 90 48 c7 c7 b8 8e 25 86 e8 d2 05 b5 fe 90 <0f> 0b 90 90 e9 79 ff ff ff e8 53 26 cd fe 0f b6 1 RSP: 0018:ffff8881067b7da0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c72ac RDX: ffff8881026a2140 RSI: ffffffff811c72b5 RDI: 0000000000000001 RBP: ffff8881067b7db0 R08: 0000000000000000 R09: 205b5d3730353139 R10: 0000000000000000 R11: 205d303938375420 R12: ffff8881086500c4 R13: ffff8881086500c4 R14: ffff8881086500b0 R15: ffff888108650040 FS: 00007f5b2961a4c0(0000) GS:ffff88823bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d7ed36fd18 CR3: 00000001482f6000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? show_regs+0xa3/0xc0 ? __warn+0xa5/0x1c0 ? refcount_warn_saturate+0xdf/0x1d0 ? report_bug+0x1fc/0x2d0 ? refcount_warn_saturate+0xdf/0x1d0 ? handle_bug+0xa1/0x110 ? exc_invalid_op+0x3c/0xb0 ? asm_exc_invalid_op+0x1f/0x30 ? __warn_printk+0xcc/0x140 ? __warn_printk+0xd5/0x140 ? refcount_warn_saturate+0xdf/0x1d0 get_net_ns+0xa4/0xc0 ? __pfx_get_net_ns+0x10/0x10 open_related_ns+0x5a/0x130 __tun_chr_ioctl+0x1616/0x2370 ? __sanitizer_cov_trace_switch+0x58/0xa0 ? __sanitizer_cov_trace_const_cmp2+0x1c/0x30 ? __pfx_tun_chr_ioctl+0x10/0x10 tun_chr_ioctl+0x2f/0x40 __x64_sys_ioctl+0x11b/0x160 x64_sys_call+0x1211/0x20d0 do_syscall_64+0x9e/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b28f165d7 Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 8 RSP: 002b:00007ffc2b59c5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b28f165d7 RDX: 0000000000000000 RSI: 00000000000054e3 RDI: 0000000000000003 RBP: 00007ffc2b59c650 R08: 00007f5b291ed8c0 R09: 00007f5b2961a4c0 R10: 0000000029690010 R11: 0000000000000246 R12: 0000000000400730 R13: 00007ffc2b59cf40 R14: 0000000000000000 R15: 0000000000000000 </TASK> Kernel panic - not syncing: kernel: panic_on_warn set ...

This is trigger as below: ns0 ns1 tun_set_iff() //dev is tun0 tun->dev = dev //ip link set tun0 netns ns1 put_net() //ref is 0 __tun_chr_ioctl() //TUNGETDEVNETNS net = dev_net(tun->dev); open_related_ns(&net->ns, get_net_ns); //ns1 get_net_ns() get_net() //addition on 0

Use maybe_get_net() in get_net_ns in case net's ref is zero to fix this

Patch / fix

  • Linux Linux 5.4.279, 5.10.221, 5.15.162, 6.1.96, 6.6.36, 6.9.7, 6.10
  • 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 6.1.99-1
  • linux Debian 14, Debian 13 6.9.7-1

debian advisories DEBIAN-CVE-2024-40958

  • linux Ubuntu 20.04 LTS 5.4.0-195.215
  • 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 5.4.0-1132.142
  • 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 5.4.0-1136.145
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1068.76

ubuntu advisories UBUNTU-CVE-2024-40958

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-2024:7000RHSA-2024:7001RHSA-2024:5363

  • kernel-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-livepatch-MICRO-6-0-RT_Update_2 Linux Micro 6.0 1-1.1
  • kernel-source Linux Micro 6.0 6.4.0-19.1
  • kernel-default Linux Micro 6.0 6.4.0-19.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-19.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_2 Linux Micro 6.0 1-1.1

suse advisories SUSE-SU-2025:20047-1SUSE-SU-2025:20044-1SUSE-SU-2024:3383-1SUSE-SU-2024:3195-1SUSE-SU-2024:3194-1SUSE-SU-2024:2947-1

  • 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-2024-40958 updated cvss 5.5

kernel: netns: Make get_net_ns() handle zero refcount net

  • 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 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix planned “Will not fix”
  • 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 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
  • 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
show 5 more
  • 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 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 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 4.0

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 4.0

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

0.27% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.