Medium

CVE-2024-49885 — mm, slub: avoid zeroing kmalloc redzone

In the Linux kernel, the following vulnerability has been resolved: mm, slub: avoid zeroing kmalloc redzone Since commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested"), setting orig_size treats the wasted space (object_size - orig_size) as a redzone. However with init_on_free=1 we clear the full object->size, including the redzone. Additionally we clear the object metadata, including the stored orig_size, making it zero, which makes check_object() treat the whole object as a redzone. These issues lead to the following BUG report with "slub_debug=FUZ init_on_free=1": [ 0.000000] ============================================================================= [ 0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten [ 0.000000] ----------------------------------------------------------------------------- [ 0.000000] [ 0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc [ 0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc [ 0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff) [ 0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8 [ 0.000000] [ 0.000000] Redzone ffff000010032850: cc cc cc cc cc cc cc cc ........ [ 0.000000] Object ffff000010032858: cc cc cc cc cc cc cc cc ........ [ 0.000000] Redzone ffff000010032860: cc cc cc cc cc cc cc cc ........ [ 0.000000] Padding ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00 ............ [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144 [ 0.000000] Hardware name: NXP i.MX95 19X19 board (DT) [ 0.000000] Call trace: [ 0.000000] dump_backtrace+0x90/0xe8 [ 0.000000] show_stack+0x18/0x24 [ 0.000000] dump_stack_lvl+0x74/0x8c [ 0.000000] dump_stack+0x18/0x24 [ 0.000000] print_trailer+0x150/0x218 [ 0.000000] check_object+0xe4/0x454 [ 0.000000] free_to_partial_list+0x2f8/0x5ec To address the issue, use orig_size to clear the used area. And restore the value of orig_size after clear the remaining area. When CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns s->object_size. So when using memset to init the area, the size can simply be orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not enabled. And orig_size can never be bigger than object_size.

Published Oct 21, 2024 · Updated Oct 21, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.28%

ahead of 21% of scored CVEs · Oct 28, 2026

Affects

Linux

Linux and 1 more

CVSS base

5.5

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 946fa0dbf2d8923a587f7348adf16563d59f1b3d and < 7299868253c0e8ba9bf31f6e5198e8eafa1e700b≥ 946fa0dbf2d8923a587f7348adf16563d59f1b3d and < 7a2e823a19746d54052c625faecf0d2d6c52ee0a≥ 946fa0dbf2d8923a587f7348adf16563d59f1b3d and < 83f0440b2f92227fcce9898118ca7fe7e0d64b1f≥ 946fa0dbf2d8923a587f7348adf16563d59f1b3d and < 59090e479ac78ae18facd4c58eb332562a23020eversion 6.2	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 6.2 and < 6.10.14≥ 6.11 and < 6.11.3	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.5	CVSS 3.1	Medium	1.8	3.6	nvd@nist.gov via NIST National Vulnerability Database
5.5	CVSS 3.1	Medium	—	—	GitHub, Inc. via GitHub Security Advisories

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov)

EPSS over time FIRST

Oct 20, 2026 → Oct 28, 2026 · 9 reading(s) · max 0.28%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 21, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 21, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 21, 2026
Fix documented
Oct 21, 2026 · NIST National Vulnerability Database
Affected products added · linux/linux kernel
Oct 21, 2026 · NIST National Vulnerability Database
CVSS changed · 5.5
Oct 21, 2026 · NIST National Vulnerability Database
Source status changed · → Modified
Oct 21, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 21, 2026 · Alertas do Telegram
2024
CVE published
Oct 21, 2024 · Linux

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 21, 2026 – Oct 21, 2026
1× Official description updated · Oct 21, 2026 – Oct 21, 2026

References

6 on the record

git.kernel.org/stable/c/83f0440b2f92227fcce9898118ca7fe7e0d64b1f
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/59090e479ac78ae18facd4c58eb332562a23020e
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/7a2e823a19746d54052c625faecf0d2d6c52ee0a
Patch, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2024-49885
GitHub Security Advisories
git.kernel.org/stable/c/7299868253c0e8ba9bf31f6e5198e8eafa1e700b
NIST National Vulnerability Database
github.com/advisories/GHSA-2h93-g5hm-9qcv
GitHub Security Advisories

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 1d
Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 1d
Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 1d
Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 1d
Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 1d
Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2024-49885 is "mm, slub: avoid zeroing kmalloc redzone", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.28% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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