blk-cgroup: Fix UAF in blkcg_unpin_online() (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.27 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Fix UAF in blkcg_unpin_online() blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To walk up, it uses blkcg_parent(blkcg) but it was calling that after blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the following UAF: ================================================================== BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270 Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117 CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022 Workqueue: cgwb_release cgwb_release_workfn Call Trace: <TASK> dump_stack_lvl+0x27/0x80 print_report+0x151/0x710 kasan_report+0xc0/0x100 blkcg_unpin_online+0x15a/0x270 cgwb_release_workfn+0x194/0x480 process_scheduled_works+0x71b/0xe20 worker_thread+0x82a/0xbd0 kthread+0x242/0x2c0 ret_from_fork+0x33/0x70 ret_from_fork_asm+0x1a/0x30 </TASK> ... Freed by task 1944: kasan_save_track+0x2b/0x70 kasan_save_free_info+0x3c/0x50 __kasan_slab_free+0x33/0x50 kfree+0x10c/0x330 css_free_rwork_fn+0xe6/0xb30 process_scheduled_works+0x71b/0xe20 worker_thread+0x82a/0xbd0 kthread+0x242/0x2c0 ret_from_fork+0x33/0x70 ret_from_fork_asm+0x1a/0x30 Note that the UAF is not easy to trigger as the free path is indirected behind a couple RCU grace periods and a work item execution. I could only trigger it with artifical msleep() injected in blkcg_unpin_online(). Fix it by reading the parent pointer before destroying the blkcg's blkg's.
Weaknesses (CWE)
- CWE-416 — Use After Free
References
- https://git.kernel.org/stable/c/83f5a87ee8caa76a917f59912a74d6811f773c67
- https://git.kernel.org/stable/c/8a07350fe070017a887433f4d6909433955be5f1
- https://git.kernel.org/stable/c/64afc6fe24c9896c0153e5a199bcea241ecb0d5c
- https://git.kernel.org/stable/c/5baa28569c924d9a90d036c2aaab79f791fedaf8
- https://git.kernel.org/stable/c/29d1e06560f0f6179062ac638b4064deb637d1ad
- https://git.kernel.org/stable/c/86e6ca55b83c575ab0f2e105cf08f98e58d3d7af
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | Linux |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CISA-ADP |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
| CVSS 3.1 | HIGH 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2024-53320
- GCVE · GCVE-0-2024-56672
CERT-FR advisories
- CERTFR-2025-AVI-0366 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0349 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0334 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0308 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0276 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0254 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0235 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0211 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0185 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0184 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0151 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0133 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0088 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.7 < 6.1.121cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.67cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.6cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 4308a434e5e08c78676aa66bc626ef78cbef0883 < 83f5a87ee8caa76a917f59912a74d6811f773c67 ; affected 4308a434e5e08c78676aa66bc626ef78cbef0883 < 8a07350fe070017a887433f4d6909433955be5f1 ; affected 4308a434e5e08c78676aa66bc626ef78cbef0883 < 64afc6fe24c9896c0153e5a199bcea241ecb0d5c ; affected 4308a434e5e08c78676aa66bc626ef78cbef0883 < 5baa28569c924d9a90d036c2aaab79f791fedaf8 ; affected 4308a434e5e08c78676aa66bc626ef78cbef0883 < 29d1e06560f0f6179062ac638b4064deb637d1ad ; affected 4308a434e5e08c78676aa66bc626ef78cbef0883 < 86e6ca55b83c575ab0f2e105cf08f98e58d3d7af |
| Linux · Linux | affected 5.7 ; unaffected 0 < 5.7 ; unaffected 5.10.234 ≤ 5.10.* ; unaffected 5.15.177 ≤ 5.15.* ; unaffected 6.1.121 ≤ 6.1.* ; unaffected 6.6.67 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |