ghsa-w46c-ww47-4hf8
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
arm64: ptrace: fix partial SETREGSET for NT_ARM_FPMR
Currently fpmr_set() doesn't initialize the temporary 'fpmr' 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.uw.fpmr, 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 FPMR will be retained.
Before this patch:
| # ./fpmr-test | Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d | SETREGSET(nt=0x40e, len=8) wrote 8 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d | | Attempting to write NT_ARM_FPMR (zero length) | SETREGSET(nt=0x40e, len=0) wrote 0 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0xffff800083963d50
After this patch:
| # ./fpmr-test | Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d | SETREGSET(nt=0x40e, len=8) wrote 8 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d | | Attempting to write NT_ARM_FPMR (zero length) | SETREGSET(nt=0x40e, len=0) wrote 0 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d
{
"affected": [],
"aliases": [
"CVE-2024-57878"
],
"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_FPMR\n\nCurrently fpmr_set() doesn\u0027t initialize the temporary \u0027fpmr\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.uw.fpmr, 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 FPMR will be retained.\n\nBefore this patch:\n\n| # ./fpmr-test\n| Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d\n| SETREGSET(nt=0x40e, len=8) wrote 8 bytes\n|\n| Attempting to read NT_ARM_FPMR::fpmr\n| GETREGSET(nt=0x40e, len=8) read 8 bytes\n| Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d\n|\n| Attempting to write NT_ARM_FPMR (zero length)\n| SETREGSET(nt=0x40e, len=0) wrote 0 bytes\n|\n| Attempting to read NT_ARM_FPMR::fpmr\n| GETREGSET(nt=0x40e, len=8) read 8 bytes\n| Read NT_ARM_FPMR::fpmr = 0xffff800083963d50\n\nAfter this patch:\n\n| # ./fpmr-test\n| Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d\n| SETREGSET(nt=0x40e, len=8) wrote 8 bytes\n|\n| Attempting to read NT_ARM_FPMR::fpmr\n| GETREGSET(nt=0x40e, len=8) read 8 bytes\n| Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d\n|\n| Attempting to write NT_ARM_FPMR (zero length)\n| SETREGSET(nt=0x40e, len=0) wrote 0 bytes\n|\n| Attempting to read NT_ARM_FPMR::fpmr\n| GETREGSET(nt=0x40e, len=8) read 8 bytes\n| Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d",
"id": "GHSA-w46c-ww47-4hf8",
"modified": "2025-02-03T15:32:01Z",
"published": "2025-01-11T15:30:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-57878"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8ab73c34e3c5b580721696665eabd799346bc50b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f5d71291841aecfe5d8435da2dfa7f58ccd18bc8"
}
],
"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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