Answer in brief
CVE-2024-56672 records a High severity (CVSS 7.8) vulnerability in blk-cgroup: Fix UAF in blkcg_unpin_online(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=4308a434e5e08c78676aa66bc626ef78cbef0883 <83f5a87ee8caa76a917f59912a74d6811f773c67 || >=4308a434e5e08c78676aa66bc626ef78cbef0883 <8a07350fe070017a887433f4d6909433955be5f1 || >=4308a434e5e08c78676aa66bc626ef78cbef0883 <64afc6fe24c9896c0153e5a199bcea241ecb0d5c || >=4308a434e5e08c78676aa66bc626ef78cbef0883 <5baa28569c924d9a90d036c2aaab79f791fedaf8 || >=4308a434e5e08c78676aa66bc626ef78cbef0883 <29d1e06560f0f6179062ac638b4064deb637d1ad || >=4308a434e5e08c78676aa66bc626ef78cbef0883 <86e6ca55b83c575ab0f2e105cf08f98e58d3d7af | 83f5a87ee8caa76a917f59912a74d6811f773c67, 8a07350fe070017a887433f4d6909433955be5f1, 64afc6fe24c9896c0153e5a199bcea241ecb0d5c, 5baa28569c924d9a90d036c2aaab79f791fedaf8, 29d1e06560f0f6179062ac638b4064deb637d1ad, 86e6ca55b83c575ab0f2e105cf08f98e58d3d7af |
| Linux/Linuxgeneric | 5.7 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <V1.1.1 | V1.1.1 |
Published upstream
Dec 27, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.