CVE-2024-49883· NVD / CVE Program· CNA Linux

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

Noroxi assessment

Priority: Monitor (action score 31/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 51db04892a993cace63415be99848970a0f15ef2, 5e811066c5ab709b070659197dccfb80ab650ddd, 8162ee5d94b8c0351be0a9321be134872a7654a1; Azure Linux 3.0 ARM 6.6.57.1-2; Azure Linux 3.0 x64 6.6.57.1-2.

Low priority for now. Upgrade to Linux Linux 51db04892a993cace63415be99848970a0f15ef2, 5e811066c5ab709b070659197dccfb80ab650ddd, 8162ee5d94b8c0351be0a9321be134872a7654a1; Azure Linux 3.0 ARM 6.6.57.1-2; Azure Linux 3.0 x64 6.6.57.1-2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2024-09789

Published: Oct 21, 2024
Updated: Aug 5, 2026
EPSS: 0.2% · 19th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.8
CNA · Linux: 7.8; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel
debian	debian linux	cpe:2.3:o:debian:debian_linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

debian debian linux11.0
linux linux kernel3.18 and later · before 4.19.323
linux linux kernel4.20 and later · before 5.4.285
linux linux kernel5.5 and later · before 5.10.227
linux linux kernel5.11 and later · before 5.15.168
linux linux kernel5.16 and later · before 6.1.113
linux linux kernel6.2 and later · before 6.6.55
linux linux kernel6.7 and later · before 6.10.14
linux linux kernel6.11 and later · before 6.11.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 3.18affected
- 10809df84a4d868db61af621bae3658494165279 and later · before e17ebe4fdd7665c93ae9459ba40fcdfb76769ac1affected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before 975ca06f3fd154c5f7742083e7b2574c57d1c0c3affected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before 5e811066c5ab709b070659197dccfb80ab650dddaffected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before 9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887aaffected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before 51db04892a993cace63415be99848970a0f15ef2affected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before 8162ee5d94b8c0351be0a9321be134872a7654a1affected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before beb7b66fb489041c50c6473100b383f7a51648fcaffected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1baffected · git
- 10809df84a4d868db61af621bae3658494165279 and later · before a164f3a432aae62ca23d03e6d926b122ee5b860daffected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.115-1	6.1.115-1
Debian:13	linux	before 6.11.4-1	6.11.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now
CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
83Now

Published before and after this one in the same product

← EarlierCVE-2024-49880Oct 21, 2024 · ext4: fix off by one issue in alloc_flex_gd()
31Monitor
← EarlierCVE-2024-49882Oct 21, 2024 · ext4: fix double brelse() the buffer of the extents path
31Monitor
Later →CVE-2024-49886Oct 21, 2024 · platform/x86: ISST: Fix the KASAN report slab-out-of-bounds bug
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	51db04892a993cace63415be99848970a0f15ef2	Vendor (CNA)
Linux Linux	5e811066c5ab709b070659197dccfb80ab650ddd	Vendor (CNA)
Linux Linux	8162ee5d94b8c0351be0a9321be134872a7654a1	Vendor (CNA)
Linux Linux	975ca06f3fd154c5f7742083e7b2574c57d1c0c3	Vendor (CNA)
Linux Linux	9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a	Vendor (CNA)
Linux Linux	a164f3a432aae62ca23d03e6d926b122ee5b860d	Vendor (CNA)
Linux Linux	beb7b66fb489041c50c6473100b383f7a51648fc	Vendor (CNA)
Linux Linux	bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1b	Vendor (CNA)
Linux Linux	e17ebe4fdd7665c93ae9459ba40fcdfb76769ac1	Vendor (CNA)
Azure Linux 3.0 ARM	6.6.57.1-2 · kernel	Microsoft (MSRC)
Azure Linux 3.0 x64	6.6.57.1-2 · kernel	Microsoft (MSRC)
debian:linux	6.1.115-1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/51db04892a993cace63415be99848970a0f15ef2

Show all references (10 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records