regmap: Fix possible double-free in regcache_rbtree_exit()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-415 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: regmap: Fix possible double-free in regcache_rbtree_exit() In regcache_rbtree_insert_to_block(), when 'present' realloc failed, the 'blk' which is supposed to assign to 'rbnode->block' will be freed, so 'rbnode->block' points a freed memory, in the error handling path of regcache_rbtree_init(), 'rbnode->block' will be freed again in regcache_rbtree_exit(), KASAN will report double-free as follows: BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390 Call Trace: slab_free_freelist_hook+0x10d/0x240 kfree+0xce/0x390 regcache_rbtree_exit+0x15d/0x1a0 regcache_rbtree_init+0x224/0x2c0 regcache_init+0x88d/0x1310 __regmap_init+0x3151/0x4a80 __devm_regmap_init+0x7d/0x100 madera_spi_probe+0x10f/0x333 [madera_spi] spi_probe+0x183/0x210 really_probe+0x285/0xc30 To fix this, moving up the assignment of rbnode->block to immediately after the reallocation has succeeded so that the data structure stays valid even if the second reallocation fails.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.12 and later | 4.4.291, 4.9.289, 4.14.254, 4.19.215, 5.4.157, 5.10.77, 5.14.16, 5.15 | Patch available | CNA |
- Linux VendorLinux Affected 3.12 and later Fixed in 4.4.291, 4.9.289, 4.14.254, 4.19.215, 5.4.157, 5.10.77, 5.14.16, 5.15 Patch available CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.12 to before 4.4.291; 4.5 to before 4.9.289; 4.10 to before 4.14.254; 4.15 to before 4.19.215; 4.20 to before 5.4.157; 5.5 to before 5.10.77; 5.11 to before 5.14.16 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* | 5.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* | 5.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* | 5.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* | 5.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* | 5.15 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:* | 5.15 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc7:*:*:*:*:*:* | 5.15 rc7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.12 to before 4.4.291; 4.5 to before 4.9.289; 4.10 to before 4.14.254; 4.15 to before 4.19.215; 4.20 to before 5.4.157; 5.5 to before 5.10.77; 5.11 to before 5.14.16 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* Versions 5.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* Versions 5.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* Versions 5.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* Versions 5.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* Versions 5.15 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:* Versions 5.15 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc7:*:*:*:*:*:* Versions 5.15 rc7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.4.291, 4.9.289, 4.14.254, 4.19.215, 5.4.157, 5.10.77, 5.14.16, 5.15
Red Hat 1 advisory
- RHSA-2022:7683 Released 2022-11-08 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-425.3.1.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-425.3.1.el8, kernel-4.18.0-425.3.1.el8, kernel-abi-stablelists-4.18.0-425.3.1.el8 +19
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2022:7683 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47483
- 2026-10-03 Alias added: GHSA-76m2-73wx-8hj7
References
Patch 8
- https://git.kernel.org/stable/c/e72dce9afbdbfa70d9b44f5908a50ff6c4858999
- https://git.kernel.org/stable/c/fc081477b47dfc3a6cb50a96087fc29674013fc2
- https://git.kernel.org/stable/c/758ced2c3878ff789801e6fee808e185c5cf08d6
- https://git.kernel.org/stable/c/3dae1a4eced3ee733d7222e69b8a55caf2d61091
- https://git.kernel.org/stable/c/1cead23c1c0bc766dacb900a3b0269f651ad596f
- https://git.kernel.org/stable/c/36e911a16b377bde0ad91a8c679069d0d310b1a6
- https://git.kernel.org/stable/c/50cc1462a668dc62949a1127388bc3af785ce047
- https://git.kernel.org/stable/c/55e6d8037805b3400096d621091dfbf713f97e83
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- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2021-47483 · CVE Program
- CVE-2021-47483 · NVD
- FIRST EPSS
- GHSA-76m2-73wx-8hj7 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47483 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences