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Fencer Vulns
medium 5.5

CVE-2024-26935 json

scsi: core: Fix unremoved procfs host directory regression

published 2024-05-01 2 y ago modified 2026-10-15 25 d ago also EUVD-2024-24197

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 15%
public exploits
0
none known

Summary

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

scsi: core: Fix unremoved procfs host directory regression

Commit fc663711b944 ("scsi: core: Remove the /proc/scsi/${proc_name} directory earlier") fixed a bug related to modules loading/unloading, by adding a call to scsi_proc_hostdir_rm() on scsi_remove_host(). But that led to a potential duplicate call to the hostdir_rm() routine, since it's also called from scsi_host_dev_release(). That triggered a regression report, which was then fixed by commit be03df3d4bfe ("scsi: core: Fix a procfs host directory removal regression"). The fix just dropped the hostdir_rm() call from dev_release().

But it happens that this proc directory is created on scsi_host_alloc(), and that function "pairs" with scsi_host_dev_release(), while scsi_remove_host() pairs with scsi_add_host(). In other words, it seems the reason for removing the proc directory on dev_release() was meant to cover cases in which a SCSI host structure was allocated, but the call to scsi_add_host() didn't happen. And that pattern happens to exist in some error paths, for example.

Syzkaller causes that by using USB raw gadget device, error'ing on usb-storage driver, at usb_stor_probe2(). By checking that path, we can see that the BadDevice label leads to a scsi_host_put() after a SCSI host allocation, but there's no call to scsi_add_host() in such path. That leads to messages like this in dmesg (and a leak of the SCSI host proc structure):

usb-storage 4-1:87.51: USB Mass Storage device detected proc_dir_entry 'scsi/usb-storage' already registered WARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377 proc_register+0x347/0x4e0 fs/proc/generic.c:376

The proper fix seems to still call scsi_proc_hostdir_rm() on dev_release(), but guard that with the state check for SHOST_CREATED; there is even a comment in scsi_host_dev_release() detailing that: such conditional is meant for cases where the SCSI host was allocated but there was no calls to {add,remove}_host(), like the usb-storage case.

This is what we propose here and with that, the error path of usb-storage does not trigger the warning anymore.

Patch / fix

  • Linux Linux 5.4.274, 5.10.215, 5.15.154, 6.1.84, 6.3, 6.6.24, 6.7.12, 6.8.3, 6.9
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem V1.1.1
  • linux Debian 12 6.1.85-1
  • linux Debian 14, Debian 13 6.7.12-1

debian advisories DEBIAN-CVE-2024-26935

  • linux Ubuntu 20.04 LTS 5.4.0-189.209
  • linux Ubuntu 22.04 LTS 5.15.0-116.126
  • linux Ubuntu 24.04 LTS 6.8.0-35.35
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1128.138
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1065.71
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1009.9
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1132.141
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1064.72

ubuntu advisories UBUNTU-CVE-2024-26935

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 4.18.0-553.37.1.el8_10
  • perf RHEL 8 4.18.0-553.37.1.el8_10
  • bpftool RHEL 8 4.18.0-553.37.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.37.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.37.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.37.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.37.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.37.1.el8_10

red hat advisories RHSA-2025:1068RHSA-2025:1067RHSA-2024:8617

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.170.2
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.170.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.170.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +6 more 5.14.21-150400.24.170.2
  • kernel-zfcpdump SLES 15 SP4-LTSS, Manager Server 4.3 5.14.21-150400.24.170.2
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.170.2
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.170.2.150400.24.86.2
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.124.1

suse advisories SUSE-SU-2026:0473-1SUSE-SU-2025:02537-1SUSE-SU-2025:02322-1SUSE-SU-2025:02321-1SUSE-SU-2025:02264-1SUSE-SU-2025:20166-1

  • kernel-rt AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel-rt-debug-modules-extra AlmaLinux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel AlmaLinux 8 4.18.0-553.37.1.el8_10

almalinux advisories ALSA-2025:1067ALSA-2025:1068ALSA-2024:8617

  • kernel-rt Rocky Linux 8 4.18.0-553.37.1.rt7.378.el8_10
  • kernel Rocky Linux 8 4.18.0-553.37.1.el8_10
  • kernel Rocky Linux 9 5.14.0-427.42.1.el9_4

rocky linux advisories RLSA-2025:1067RLSA-2025:1068RLSA-2024:8617

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-2024-26935 updated cvss 5.5

kernel: scsi: core: Fix unremoved procfs host directory regression

  • 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 AppStream (v. 9) rv 5.14.0-427.42.1.el9_4, perf 5.14.0-427.42.1.el9_4, rtla 5.14.0-427.42.1.el9_4, kernel-devel-matched 5.14.0-427.42.1.el9_4, kernel-64k-devel-matched 5.14.0-427.42.1.el9_4, kernel-debug-devel-matched 5.14.0-427.42.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.37.1.el8_10, kernel 4.18.0-553.37.1.el8_10, bpftool 4.18.0-553.37.1.el8_10, kernel-core 4.18.0-553.37.1.el8_10, kernel-tools 4.18.0-553.37.1.el8_10, python3-perf 4.18.0-553.37.1.el8_10, +15 more
    fixed: vendor fix RHSA-2025:1068
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.42.1.el9_4, kernel 5.14.0-427.42.1.el9_4, kernel-64k 5.14.0-427.42.1.el9_4, kernel-core 5.14.0-427.42.1.el9_4, kernel-tools 5.14.0-427.42.1.el9_4, python3-perf 5.14.0-427.42.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.37.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.37.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.37.1.el8_10
    fixed: vendor fix RHSA-2025:1068
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.42.1.el9_4
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-kvm 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-core 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-modules 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-debug-kvm 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-debug-core 4.18.0-553.37.1.rt7.378.el8_10, +4 more
    fixed: vendor fix RHSA-2025:1067
  • Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.42.1.el9_4, kernel-rt-kvm 5.14.0-427.42.1.el9_4, kernel-rt-core 5.14.0-427.42.1.el9_4, kernel-rt-modules 5.14.0-427.42.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.42.1.el9_4, kernel-rt-debug-core 5.14.0-427.42.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:8617
show 3 more
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-core 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-modules 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-debug-core 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-debug-modules 4.18.0-553.37.1.rt7.378.el8_10, kernel-rt-modules-extra 4.18.0-553.37.1.rt7.378.el8_10, +2 more
    fixed: vendor fix RHSA-2025:1067
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.42.1.el9_4, kernel-rt-core 5.14.0-427.42.1.el9_4, kernel-rt-modules 5.14.0-427.42.1.el9_4, kernel-rt-debug-core 5.14.0-427.42.1.el9_4, kernel-rt-modules-core 5.14.0-427.42.1.el9_4, kernel-rt-debug-modules 5.14.0-427.42.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:8617
  • 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
    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 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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% 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 SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Classification

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.