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Fencer Vulns
medium 5.5

CVE-2024-38661 json

s390/ap: Fix crash in AP internal function modify_bitmap()

published 2024-06-25 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-37514

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

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

s390/ap: Fix crash in AP internal function modify_bitmap()

A system crash like this

Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403 Fault in home space mode while using kernel ASCE. AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d Oops: 0038 ilc:3 [#1] PREEMPT SMP Modules linked in: mlx5_ib ... CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8 Hardware name: IBM 3931 A01 704 (LPAR) Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3 000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0 000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff 000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8 Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a 0000014b75e7b600: 18b2 lr %r11,%r2 #0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616 >0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13) 0000014b75e7b60c: a7680001 lhi %r6,1 0000014b75e7b610: 187b lr %r7,%r11 0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654 0000014b75e7b616: 18e9 lr %r14,%r9 Call Trace: [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8 ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8) [<0000014b75e7b758>] apmask_store+0x68/0x140 [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8 [<0000014b75598524>] vfs_write+0x1b4/0x448 [<0000014b7559894c>] ksys_write+0x74/0x100 [<0000014b7618a440>] __do_syscall+0x268/0x328 [<0000014b761a3558>] system_call+0x70/0x98 INFO: lockdep is turned off. Last Breaking-Event-Address: [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8 Kernel panic - not syncing: Fatal exception: panic_on_oops

occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value (like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.

The fix is simple: use unsigned long values for the internal variables. The correct checks are already in place in the function but a simple int for the internal variables was used with the possibility to overflow.

Patch / fix

  • Linux Linux 4.19.316, 5.4.278, 5.10.219, 5.15.161, 6.1.94, 6.6.34, 6.9.5, 6.10
  • linux Debian 12 6.1.94-1
  • linux Debian 14, Debian 13 6.9.7-1

debian advisories DEBIAN-CVE-2024-38661

  • 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-2024-38661

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 Linux Micro 6.0 6.4.0-9.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1

suse advisories SUSE-SU-2025:20028-1SUSE-SU-2025:20008-1SUSE-SU-2024:2973-1SUSE-SU-2024:2939-1SUSE-SU-2024:2896-1SUSE-SU-2024:2571-1

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-2024-38661 updated cvss 5.5

kernel: s390/ap: Fix crash in AP internal function modify_bitmap()

  • 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 Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% 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

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.