Linux Kernel up to 6.18.53/7.2.7/7.3-rc3 memcg mm/memcontrol.c obj_cgroup_charge_pages allocation of resources

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 4.2 | $0-$5k | 0.38 |
Summary
A vulnerability was found in Linux Kernel up to 6.18.53/7.2.7/7.3-rc3. It has been declared as problematic. The impacted element is the function obj_cgroup_charge_pages of the file mm/memcontrol.c of the component memcg. Executing a manipulation can lead to allocation of resources.
This vulnerability is handled as CVE-2026-98414. It is possible to launch the attack on the local host. There is not any exploit available.
It is recommended to upgrade the affected component.
Details
A vulnerability was found in Linux Kernel up to 6.18.53/7.2.7/7.3-rc3. It has been declared as problematic. This vulnerability affects the function obj_cgroup_charge_pages of the file mm/memcontrol.c of the component memcg. The manipulation with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect availability. CVE summarizes:
In the Linux kernel, the following vulnerability has been resolved: memcg: avoid charging the root memcg from obj_cgroup_charge_pages() obj_cgroup_charge_pages() resolves the objcg to its memcg and calls try_charge_memcg(), which does not short circuit the root memcg. That memcg can be the root memcg: obj_cgroup_is_root() reflects the memcg the objcg was created for and is never updated, while memcg_reparent_objcgs() does redirect objcg->memcg to the parent on rmdir. An objcg of a dying child of root therefore passes every obj_cgroup_is_root() filter but resolves to the root memcg. Folios keep the objcg they were charged with, so this is easy to reach through zswap: allocate anon memory in a cgroup, move the task out, remove the cgroup, then write to the root cgroup's memory.reclaim. The reclaimed folios are charged through the reparented objcg and end up in refill_stock() with the root memcg: WARNING: mm/memcontrol.c:2198 at refill_stock+0x644/0x940 refill_stock+0x644/0x940 try_charge_memcg+0x12d6/0x1570 __obj_cgroup_charge+0x35/0xf0 obj_cgroup_charge+0x1de/0x210 obj_cgroup_charge_zswap+0x83/0x270 zswap_store+0x1620/0x2000 swap_writeout+0x94c/0x14c0 shrink_folio_list+0x3388/0x52b0 [...] try_to_free_mem_cgroup_pages+0x30d/0x830 user_proactive_reclaim+0x504/0x840 memory_reclaim+0x1f/0x30 Beyond the warning, the charge is asymmetric: obj_cgroup_uncharge_pages() skips refill_stock() for the root memcg, so the root's page counter grows and is never uncharged. It is not user visible, since memory.current is not exposed on the root, but it is a leak. Use try_charge(), which returns early for the root memcg, restoring the symmetry with obj_cgroup_uncharge_pages(). The above sequence was scripted into a standalone reproducer (zswap on, swap on a virtio disk, 512MB of anon memory faulted in inside a child of the root cgroup, the task then migrated to the root cgroup, the child removed, followed by "echo 600M swappiness=max > memory.reclaim" on the root) and run in a CONFIG_DEBUG_VM=y VM. It reproduces the splat on the first zswap store of a reparented folio, with the same call chain as the report. With this patch applied the splat is gone while the zswap store count over the run is unchanged, so the same path is still exercised. cgroup selftests test_zswap, test_kmem and test_memcontrol show no new failures.
The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-98414 since 09/25/2026. The exploitation appears to be easy. Local access is required to approach this attack. The exploitation needs additional levels of successful authentication. Technical details are known, but there is no available exploit.
Upgrading to version 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch d5cdff14c385bf42d03c0dd4c3e88ddf4c28b8a9/ecc03877b1b05cb1e3a72175ccb868383eccc518/6e673d0879ef78c395cfe0d3ba316690a60055d8 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Product
Type
Vendor
Name
Version
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 6.18.35
- 6.18.36
- 6.18.37
- 6.18.38
- 6.18.39
- 6.18.40
- 6.18.41
- 6.18.42
- 6.18.43
- 6.18.44
- 6.18.45
- 6.18.46
- 6.18.47
- 6.18.48
- 6.18.49
- 6.18.50
- 6.18.51
- 6.18.52
- 6.18.53
- 7.2.0
- 7.2.1
- 7.2.2
- 7.2.3
- 7.2.4
- 7.2.5
- 7.2.6
- 7.2.7
- 7.3-rc1
- 7.3-rc2
- 7.3-rc3
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 4.4VulDB Meta Temp Score: 4.2
VulDB Base Score: 4.4
VulDB Temp Score: 4.2
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Allocation of resourcesCWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒
Physical: Partially
Local: Yes
Remote: No
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
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Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 6.18.54/7.2.8/7.3-rc4
Patch: d5cdff14c385bf42d03c0dd4c3e88ddf4c28b8a9/ecc03877b1b05cb1e3a72175ccb868383eccc518/6e673d0879ef78c395cfe0d3ba316690a60055d8
Timeline
09/25/2026 CVE reserved10/14/2026 Advisory disclosed
10/14/2026 VulDB entry created
10/14/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-98414 (🔒)
GCVE (CVE): GCVE-0-2026-98414
GCVE (VulDB): GCVE-100-419866
Entry
Created: 10/14/2026 16:06Changes: 10/14/2026 16:06 (60)
Complete: 🔍
Cache ID: 216::103
If you want to get best quality of vulnerability data, you may have to visit VulDB.
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