GHSA-4QP2-JGHX-88MP
Vulnerability from github – Published: 2026-07-27 21:31 – Updated: 2026-07-27 21:31In the Linux kernel, the following vulnerability has been resolved:
crypto: asymmetric_keys - fix OOB read in pefile_digest_pe_contents
pefile_digest_pe_contents() computes the trailing-data hash length as pelen - (hashed_bytes + certs_size). A crafted PE can make the addition exceed pelen, causing the unsigned subtraction to underflow to ~4 GiB. This is passed to crypto_shash_update() which reads out of bounds and panics on unmapped vmalloc guard pages.
BUG: unable to handle page fault for address: ffffc900038d8000 Oops: Oops: 0000 [#1] SMP KASAN NOPTI RIP: 0010:sha256_blocks_generic (lib/crypto/sha256.c:152) Call Trace: __sha256_update (lib/crypto/sha256.c:208) crypto_sha256_update (crypto/sha256.c:142) verify_pefile_signature (crypto/asymmetric_keys/verify_pefile.c:436) kexec_kernel_verify_pe_sig (kernel/kexec_file.c:151) __do_sys_kexec_file_load (kernel/kexec_file.c:406) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Kernel panic - not syncing: Fatal exception
Validate that the addition does not overflow and the result does not exceed pelen before the subtraction. Return -ELIBBAD on failure.
{
"affected": [],
"aliases": [
"CVE-2026-64544"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-27T21:17:06Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: asymmetric_keys - fix OOB read in pefile_digest_pe_contents\n\npefile_digest_pe_contents() computes the trailing-data hash length as\npelen - (hashed_bytes + certs_size). A crafted PE can make the addition\nexceed pelen, causing the unsigned subtraction to underflow to ~4 GiB.\nThis is passed to crypto_shash_update() which reads out of bounds and\npanics on unmapped vmalloc guard pages.\n\n BUG: unable to handle page fault for address: ffffc900038d8000\n Oops: Oops: 0000 [#1] SMP KASAN NOPTI\n RIP: 0010:sha256_blocks_generic (lib/crypto/sha256.c:152)\n Call Trace:\n \u003cTASK\u003e\n __sha256_update (lib/crypto/sha256.c:208)\n crypto_sha256_update (crypto/sha256.c:142)\n verify_pefile_signature (crypto/asymmetric_keys/verify_pefile.c:436)\n kexec_kernel_verify_pe_sig (kernel/kexec_file.c:151)\n __do_sys_kexec_file_load (kernel/kexec_file.c:406)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n \u003c/TASK\u003e\n Kernel panic - not syncing: Fatal exception\n\nValidate that the addition does not overflow and the result does not\nexceed pelen before the subtraction. Return -ELIBBAD on failure.",
"id": "GHSA-4qp2-jghx-88mp",
"modified": "2026-07-27T21:31:26Z",
"published": "2026-07-27T21:31:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64544"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/627938383761fb4334b41ebe7ef438d6b8b19d60"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6acd2fbd00f9c72aebefce63fc2e73e8f3d79061"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7016377699b5b25b7ec3c0bf2ec3f983c7e95f7c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/803591785d33cf13b6f73ce2796e8b9e6d5e6526"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/89efd998470a93284b7ad5a20d4e0e3c6858ae8e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b798ada5a5d1cb4cc4cfa72074b1b463eca6c506"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e162bc386e71b5412425a38ee048e8d2185491b9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f7dd32c5179d7755de18e21d5674b08f9e5cb180"
}
],
"schema_version": "1.4.0",
"severity": []
}
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