CVE-2023-52854
padata: Fix refcnt handling in padata_free_shell()
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: padata: Fix refcnt handling in padata_free_shell() In a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead to system UAF (Use-After-Free) issues. Due to the lengthy analysis of the pcrypt_aead01 function call, I'll describe the problem scenario using a simplified model: Suppose there's a user of padata named `user_function` that adheres to the padata requirement of calling `padata_free_shell` after `serial()` has been invoked, as demonstrated in the following code: ```c struct request { struct padata_priv padata; struct completion *done; }; void parallel(struct padata_priv *padata) { do_something(); } void serial(struct padata_priv *padata) { struct request *request = container_of(padata, struct request, padata); complete(request->done); } void user_function() { DECLARE_COMPLETION(done) padata->parallel = parallel; padata->serial = serial; padata_do_parallel(); wait_for_completion(&done); padata_free_shell(); } ``` In the corresponding padata.c file, there's the following code: ```c static void padata_serial_worker(struct work_struct *serial_work) { ... cnt = 0; while (!list_empty(&local_list)) { ... padata->serial(padata); cnt++; } local_bh_enable(); if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } ``` Because of the high system load and the accumulation of unexecuted softirq at this moment, `local_bh_enable()` in padata takes longer to execute than usual. Subsequently, when accessing `pd->refcnt`, `pd` has already been released by `padata_free_shell()`, resulting in a UAF issue with `pd->refcnt`. The fix is straightforward: add `refcount_dec_and_test` before calling `padata_free_pd` in `padata_free_shell`.
Timeline
ID reserved
By Linux
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.24% · top 85% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 07928d9bfc81640bab36f5190e8725894d93b659 – < 41aad9d6953984d134fc50f631f24ef476875d4d
- affected 07928d9bfc81640bab36f5190e8725894d93b659 – < 0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5
- affected 07928d9bfc81640bab36f5190e8725894d93b659 – < c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275
- affected 07928d9bfc81640bab36f5190e8725894d93b659 – < 1e901bcb8af19416b65f5063a4af7996e5a51d7f
- affected 07928d9bfc81640bab36f5190e8725894d93b659 – < 1734a79e951914f1db2c65e635012a35db1c674b
- affected 07928d9bfc81640bab36f5190e8725894d93b659 – < 7ddc21e317b360c3444de3023bcc83b85fabae2f
- affected 13721e447acc2b82c19cf72e9e6c4291c77693ed
- affected 7a2ccb65f90168edc2348495bb56093c466ffa39
- affected 928cf3d733c4efc221e1a78b14cb2ee066627260
- affected c9da8ee1491719001a444f4af688b75e72b58418
- affected dc34710a7aba5207e7cb99d11588c04535b3c53d
- affected 5fefc9b3e3584a1ce98da27c38e1b8dda1939d74
- affected 26daf8e6515c2dcd25d235468420b9f46e0acdac
- affected 3.16.84 – < 3.17
- affected 4.4.215 – < 4.5
- affected 4.9.215 – < 4.10
- affected 4.14.172 – < 4.15
- affected 4.19.103 – < 4.20
- affected 5.4.19 – < 5.5
- affected 5.5.3 – < 5.6
- affected 5.6
- unaffected < 5.6
- unaffected 5.10.201 – ≤ 5.10.*
- unaffected 5.15.139 – ≤ 5.15.*
- unaffected 6.1.63 – ≤ 6.1.*
- unaffected 6.5.12 – ≤ 6.5.*
- unaffected 6.6.2 – ≤ 6.6.*
- unaffected 6.7 – ≤ *
References (6)
- https://git.kernel.org/stable/c/41aad9d6953984d134fc50f631f24ef476875d4d (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/1e901bcb8af19416b65f5063a4af7996e5a51d7f (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/1734a79e951914f1db2c65e635012a35db1c674b (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/7ddc21e317b360c3444de3023bcc83b85fabae2f (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2023-52854)Record last updated .