riscv: Fix register corruption from uninitialized cregs on error
In the Linux kernel, the following vulnerability has been resolved: riscv: Fix register corruption from uninitialized cregs on error compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when user_regset_copyin() fails. Since cregs is an uninitialized stack variable, a copyin failure causes uninitialized stack data to be written into the target task's pt_regs, corrupting its register state and potentially leaking kernel stack contents. compat_restore_sigcontext() has the same issue: it calls cregs_to_regs() even when __copy_from_user() fails, leading to the same corruption of the signal-returning task's register state on error. Only call cregs_to_regs() when the user copy succeeds.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 6.1.187, 6.12.108, 6.18.49, 6.6.156, 7.0.11
- CVEs
- CVE-2026-64082
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 06:52 UTC · Revision 1
Source evidence
riscv: Fix register corruption from uninitialized cregs on error
core-osv · Original sourcePublished 19 Jul 2026, 15:39 UTC
In the Linux kernel, the following vulnerability has been resolved: riscv: Fix register corruption from uninitialized cregs on error compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when user_regset_copyin() fails. Since cregs is an uninitialized stack variable, a copyin failure causes uninitialized stack data to be written into the target task's pt_regs, corrupting its register state and potentially leaking kernel stack contents. compat_restore_sigcontext() has the same issue: it calls cregs_to_regs() even when __copy_from_user() fails, leading to the same corruption of the signal-returning task's register state on error. Only call cregs_to_regs() when the user copy succeeds.
osv:CVE-2026-64082
Kernel
Fixed versions: 6.1.187, 6.6.156, 6.12.108, 6.18.49, 7.0.11
Complete source record
{
"id": "4ef24d31718f39a65e5951fbf44a39fc9524b33f87535fb2d5f5d9c0b0e70c8a",
"url": "https://osv.dev/vulnerability/CVE-2026-64082",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "riscv: Fix register corruption from uninitialized cregs on error",
"summary": "In the Linux kernel, the following vulnerability has been resolved: riscv: Fix register corruption from uninitialized cregs on error compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when user_regset_copyin() fails. Since cregs is an uninitialized stack variable, a copyin failure causes uninitialized stack data to be written into the target task's pt_regs, corrupting its register state and potentially leaking kernel stack contents. compat_restore_sigcontext() has the same issue: it calls cregs_to_regs() even when __copy_from_user() fails, leading to the same corruption of the signal-returning task's register state on error. Only call cregs_to_regs() when the user copy succeeds.",
"evidence": "osv:CVE-2026-64082",
"products": [
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"package": {
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"database_specific": {
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],
"modified": "2026-10-28T02:30:26.883981268Z",
"provider": "osv",
"references": [
"https://git.kernel.org/stable/c/0599aa23734c48de9bce36d043a9ec90c23945a1",
"https://git.kernel.org/stable/c/2a7d1daf2674fe7d5b1cc99a4e3b5f0f72d5958f",
"https://git.kernel.org/stable/c/66dedb6028c3df6c6a3372dd935b823917e150d5",
"https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4",
"https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50",
"https://git.kernel.org/stable/c/f2d88b0d7aebfa4643fc58bbae57210c6daff9c6",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64082.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-64082",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
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"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 493143,
"published_at": "2026-07-19T15:39:54.074+00:00"
}