Skip to content
Fencer Vulns
high 7.8

CVE-2024-49883 json

ext4: aovid use-after-free in ext4_ext_insert_extent()

published 2024-10-21 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-43583

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 20%
public exploits
0
none known

Summary

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

ext4: aovid use-after-free in ext4_ext_insert_extent()

As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values:

ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr

================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...]

Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...]

Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ==================================================================

So use *ppath to update the path to avoid the above problem.

Patch / fix

  • Linux Linux 4.19.323, 5.4.285, 5.10.227, 5.15.168, 6.1.113, 6.6.55, 6.10.14, 6.11.3, 6.12
  • linux Debian 12 6.1.115-1
  • linux Debian 14, Debian 13 6.11.4-1

debian advisories DEBIAN-CVE-2024-49883

  • linux Ubuntu 20.04 LTS 5.4.0-208.228
  • linux Ubuntu 22.04 LTS 5.15.0-127.137
  • linux Ubuntu 24.04 LTS 6.8.0-54.56
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1140.150
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1073.79
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1023.25
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1143.152
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1072.80

ubuntu advisories UBUNTU-CVE-2024-49883

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 9 5.14.0-570.12.1.el9_6
  • rv RHEL 9 5.14.0-570.12.1.el9_6
  • perf RHEL 9 5.14.0-570.12.1.el9_6
  • rtla RHEL 9 5.14.0-570.12.1.el9_6
  • libperf RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-rt RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-64k RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-core RHEL 9 5.14.0-570.12.1.el9_6

red hat advisories RHSA-2025:6966

  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1.21.4
  • kernel-livepatch-MICRO-6-0_Update_4 Linux Micro 6.1, Linux Micro 6.0 1-1.2
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-22.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-22.1
  • kernel-livepatch-MICRO-6-0-RT_Update_4 Linux Micro 6.1, Linux Micro 6.0 1-1.1

suse advisories SUSE-SU-2025:20164-1SUSE-SU-2025:20247-1SUSE-SU-2025:20163-1SUSE-SU-2025:20246-1SUSE-SU-2025:0034-1SUSE-SU-2024:4387-1

  • kernel-source-longterm openSUSE Tumbleweed 6.12.11-1.1
  • kernel-source openSUSE Tumbleweed 6.11.8-1.1

opensuse advisories openSUSE-SU-2025:14705-1openSUSE-SU-2024:14500-1

  • kernel CBL-Mariner 2.0 5.15.173.1-1

azure linux advisories AZL-51360

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-2024-49883 updated cvss 5.5

kernel: ext4: aovid use-after-free in ext4_ext_insert_extent()

  • 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 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.12.1.el9_6, perf 5.14.0-570.12.1.el9_6, rtla 5.14.0-570.12.1.el9_6, python3-perf 5.14.0-570.12.1.el9_6, kernel-devel-matched 5.14.0-570.12.1.el9_6, kernel-64k-devel-matched 5.14.0-570.12.1.el9_6, +7 more Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.12.1.el9_6, kernel-64k 5.14.0-570.12.1.el9_6, kernel-core 5.14.0-570.12.1.el9_6, kernel-tools 5.14.0-570.12.1.el9_6, kernel-modules 5.14.0-570.12.1.el9_6, kernel-64k-core 5.14.0-570.12.1.el9_6, +27 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.12.1.el9_6 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-64k 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-64k-core 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-kvm 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +6 more
    fixed: vendor fix RHSA-2025:6966

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-25-226-07 updated cvss 5.5

Siemens Third-Party Components in SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) < 3.2
    affected: fixed in V3.2 support.industry.siemens.com
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family < 3.2
    affected: fixed in V3.2
  • Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family < 3.2
    affected: fixed in V3.2 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

0.28% chance of exploitation in the next 30 days, higher than 20% 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

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.