Answer in brief
CVE-2025-21727 records a High severity (CVSS 7.8) vulnerability in padata: fix UAF in padata_reorder. 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.
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). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=b128a30409356df65f1a51cff3eb986cac8cfedc <f78170bee51469734b1a306a74fc5f777bb22ba6 || >=b128a30409356df65f1a51cff3eb986cac8cfedc <f3e0b9f790f8e8065d59e67b565a83154d9f3079 || >=b128a30409356df65f1a51cff3eb986cac8cfedc <0ae2f332cfd2d74cf3ce344ec9938cf3e29c3ccd || >=b128a30409356df65f1a51cff3eb986cac8cfedc <bbccae982e9fa1d7abcb23a5ec81cb0ec883f7de || >=b128a30409356df65f1a51cff3eb986cac8cfedc <573ac9c70bf7885dc85d82fa44550581bfc3b738 || >=b128a30409356df65f1a51cff3eb986cac8cfedc <80231f069240d52e98b6a317456c67b2eafd0781 || >=b128a30409356df65f1a51cff3eb986cac8cfedc <e01780ea4661172734118d2a5f41bc9720765668 | f78170bee51469734b1a306a74fc5f777bb22ba6, f3e0b9f790f8e8065d59e67b565a83154d9f3079, 0ae2f332cfd2d74cf3ce344ec9938cf3e29c3ccd, bbccae982e9fa1d7abcb23a5ec81cb0ec883f7de, 573ac9c70bf7885dc85d82fa44550581bfc3b738, 80231f069240d52e98b6a317456c67b2eafd0781, e01780ea4661172734118d2a5f41bc9720765668 |
| Linux/Linuxgeneric | 5.4 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
Published upstream
Feb 27, 2025
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: padata: fix UAF in padata_reorder A bug was found when run ltp test: BUG: KASAN: slab-use-after-free in padata_find_next+0x29/0x1a0 Read of size 4 at addr ffff88bbfe003524 by task kworker/u113:2/3039206 CPU: 0 PID: 3039206 Comm: kworker/u113:2 Kdump: loaded Not tainted 6.6.0+ Workqueue: pdecrypt_parallel padata_parallel_worker Call Trace: <TASK> dump_stack_lvl+0x32/0x50 print_address_description.constprop.0+0x6b/0x3d0 print_report+0xdd/0x2c0 kasan_report+0xa5/0xd0 padata_find_next+0x29/0x1a0 padata_reorder+0x131/0x220 padata_parallel_worker+0x3d/0xc0 process_one_work+0x2ec/0x5a0 If 'mdelay(10)' is added before calling 'padata_find_next' in the 'padata_reorder' function, this issue could be reproduced easily with ltp test (pcrypt_aead01). This can be explained as bellow: pcrypt_aead_encrypt ... padata_do_parallel refcount_inc(&pd->refcnt); // add refcnt ... padata_do_serial padata_reorder // pd while (1) { padata_find_next(pd, true); // using pd queue_work_on ... padata_serial_worker crypto_del_alg padata_put_pd_cnt // sub refcnt padata_free_shell padata_put_pd(ps->pd); // pd is freed // loop again, but pd is freed // call padata_find_next, UAF } In the padata_reorder function, when it loops in 'while', if the alg is deleted, the refcnt may be decreased to 0 before entering 'padata_find_next', which leads to UAF. As mentioned in [1], do_serial is supposed to be called with BHs disabled and always happen under RCU protection, to address this issue, add synchronize_rcu() in 'padata_free_shell' wait for all _do_serial calls to finish. [1] https://lore.kernel.org/all/[email protected]/ [2] https://lore.kernel.org/linux-kernel/jfjz5d7zwbytztackem7ibzalm5lnxldi2eofeiczqmqs2m7o6@fq426cwnjtkm/
Quoted source text, attributed separately from HOL analysis.