ghsa-xfvh-9mxf-99vm
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
arm64: ptrace: fix partial SETREGSET for NT_ARM_POE
Currently poe_set() doesn't initialize the temporary 'ctrl' variable, and a SETREGSET call with a length of zero will leave this uninitialized. Consequently an arbitrary value will be written back to target->thread.por_el0, potentially leaking up to 64 bits of memory from the kernel stack. The read is limited to a specific slot on the stack, and the issue does not provide a write mechanism.
Fix this by initializing the temporary value before copying the regset from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG, NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing contents of POR_EL1 will be retained.
Before this patch:
| # ./poe-test | Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d | SETREGSET(nt=0x40f, len=8) wrote 8 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d | | Attempting to write NT_ARM_POE (zero length) | SETREGSET(nt=0x40f, len=0) wrote 0 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0xffff8000839c3d50
After this patch:
| # ./poe-test | Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d | SETREGSET(nt=0x40f, len=8) wrote 8 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d | | Attempting to write NT_ARM_POE (zero length) | SETREGSET(nt=0x40f, len=0) wrote 0 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d
{
"affected": [],
"aliases": [
"CVE-2024-57877"
],
"database_specific": {
"cwe_ids": [
"CWE-908"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-01-11T15:15:08Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: ptrace: fix partial SETREGSET for NT_ARM_POE\n\nCurrently poe_set() doesn\u0027t initialize the temporary \u0027ctrl\u0027 variable,\nand a SETREGSET call with a length of zero will leave this\nuninitialized. Consequently an arbitrary value will be written back to\ntarget-\u003ethread.por_el0, potentially leaking up to 64 bits of memory from\nthe kernel stack. The read is limited to a specific slot on the stack,\nand the issue does not provide a write mechanism.\n\nFix this by initializing the temporary value before copying the regset\nfrom userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG,\nNT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing\ncontents of POR_EL1 will be retained.\n\nBefore this patch:\n\n| # ./poe-test\n| Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d\n| SETREGSET(nt=0x40f, len=8) wrote 8 bytes\n|\n| Attempting to read NT_ARM_POE::por_el0\n| GETREGSET(nt=0x40f, len=8) read 8 bytes\n| Read NT_ARM_POE::por_el0 = 0x900d900d900d900d\n|\n| Attempting to write NT_ARM_POE (zero length)\n| SETREGSET(nt=0x40f, len=0) wrote 0 bytes\n|\n| Attempting to read NT_ARM_POE::por_el0\n| GETREGSET(nt=0x40f, len=8) read 8 bytes\n| Read NT_ARM_POE::por_el0 = 0xffff8000839c3d50\n\nAfter this patch:\n\n| # ./poe-test\n| Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d\n| SETREGSET(nt=0x40f, len=8) wrote 8 bytes\n|\n| Attempting to read NT_ARM_POE::por_el0\n| GETREGSET(nt=0x40f, len=8) read 8 bytes\n| Read NT_ARM_POE::por_el0 = 0x900d900d900d900d\n|\n| Attempting to write NT_ARM_POE (zero length)\n| SETREGSET(nt=0x40f, len=0) wrote 0 bytes\n|\n| Attempting to read NT_ARM_POE::por_el0\n| GETREGSET(nt=0x40f, len=8) read 8 bytes\n| Read NT_ARM_POE::por_el0 = 0x900d900d900d900d",
"id": "GHSA-xfvh-9mxf-99vm",
"modified": "2025-02-03T15:32:01Z",
"published": "2025-01-11T15:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-57877"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4105dd76bc8ad6529d47157ef0565cb84ca6676c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/594bfc4947c4fcabba1318d8384c61a29a6b89fb"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
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