Answer in brief
CVE-2024-56672 records a Unknown severity 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). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2024-56672 records a Unknown severity 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). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| 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 <* | * |
Published upstream
Dec 27, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 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.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| 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 <* | * |
Published upstream
Dec 27, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 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.