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TI-2021-22136 Aliases CVE-2021-47483GHSA-76m2-73wx-8hj7

regmap: Fix possible double-free in regcache_rbtree_exit()

Priority LOW 33CWE-415Published · Updated

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

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00229 13th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.4.291, 4.9.289, 4.14.254 +5Red Hat: 1 advisoryRed Hat: 2 fixed, 3 without a fix

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

VendorProductAffected versionsFixed inStatusSource
LinuxLinux3.12 and later4.4.291, 4.9.289, 4.14.254, 4.19.215, 5.4.157, 5.10.77, 5.14.16, 5.15Patch availableCNA
  • 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

CPEVersionsRoleVendor
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 5.14.16VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*5.15 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*5.15 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*5.15 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*5.15 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*5.15 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*5.15 rc6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.15:rc7:*:*:*:*:*:*5.15 rc7VulnerableLinux
  • 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 Moderate
    kernel 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 →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo 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

  1. 2026-10-02 Threatist record created from CVE-2021-47483
  2. 2026-10-03 Alias added: GHSA-76m2-73wx-8hj7

References

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources