CVE-2026-98923
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: arm64: io: Reject non-user protection in ioremap_prot() Mapping a stack-top page via /dev/mem with PROT_NONE and then reading that process's /proc/<pid>/cmdline triggers a spurious WARN in ioremap_prot() through generic_access_phys(): WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys Call trace: generic_access_phys+0x1c8/0x228 (P) __access_remote_vm+0x2b4/0x398 access_remote_vm+0x14/0x30 get_mm_cmdline+0xf8/0x2a0 proc_pid_cmdline_read+0x68/0x120 generic_access_phys() passes the protection derived from the user PTE to ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a present-invalid PTE, so pte_present() still returns true and the protection reaches ioremap_prot(). A PROT_NONE mapping does not have PTE_USER, causing the existing WARN_ON_ONCE() in ioremap_prot() to fire even though this is a valid user mapping. Execute-only mappings have the same issue and must not be readable through this path either. ioremap_prot() should therefore reject protection values without PTE_USER without warning. This makes the access fail cleanly for PROT_NONE and execute-only mappings while retaining the existing user-protection contract.
View original CVE JSON
{
"id": "CVE-2026-98923",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-23T13:17:12.957",
"lastModified": "2026-10-23T13:17:12.957",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: io: Reject non-user protection in ioremap_prot()\n\nMapping a stack-top page via /dev/mem with PROT_NONE and then\nreading that process's /proc/<pid>/cmdline triggers a spurious WARN\nin ioremap_prot() through generic_access_phys():\n\n WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys\n Call trace:\n generic_access_phys+0x1c8/0x228 (P)\n __access_remote_vm+0x2b4/0x398\n access_remote_vm+0x14/0x30\n get_mm_cmdline+0xf8/0x2a0\n proc_pid_cmdline_read+0x68/0x120\n\ngeneric_access_phys() passes the protection derived from the user PTE\nto ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a\npresent-invalid PTE, so pte_present() still returns true and the\nprotection reaches ioremap_prot().\n\nA PROT_NONE mapping does not have PTE_USER, causing the existing\nWARN_ON_ONCE() in ioremap_prot() to fire even though this is a valid\nuser mapping. Execute-only mappings have the same issue and must not\nbe readable through this path either.\n\nioremap_prot() should therefore reject protection values without\nPTE_USER without warning. This makes the access fail cleanly for\nPROT_NONE and execute-only mappings while retaining the existing\nuser-protection contract."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"arch/arm64/include/asm/io.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "64858b76ec67c5fc40fef8ec1841fecb78c1ebde",
"lessThan": "fddc90d4af4550af410f52d11bbf6b5f36443838",
"versionType": "git",
"status": "affected"
},
{
"version": "eeecafce5afffb4da703666ebefbd4d6e2a5abf6",
"lessThan": "0b04af3d88bb7fc69b2d92457890608860e42365",
"versionType": "git",
"status": "affected"
},
{
"version": "3d64dcc0799c2d6921ba027716b7be721eb19fa8",
"lessThan": "b17aa4955e3a694c663ebe99626e4c76ca4f7cfb",
"versionType": "git",
"status": "affected"
},
{
"version": "8f098037139b294050053123ab2bc0f819d08932",
"lessThan": "9b583795feb51f8d50203228d001760d1344ef01",
"versionType": "git",
"status": "affected"
},
{
"version": "8f098037139b294050053123ab2bc0f819d08932",
"lessThan": "bb756b11ad63832ebee58caf9e8f9381eaecff9f",
"versionType": "git",
"status": "affected"
},
{
"version": "d1ad8fe7f72d73e1617bac79f2ec7a3bedf47e2a",
"versionType": "git",
"status": "affected"
},
{
"version": "6.6.143",
"lessThan": "6.6.158",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.12.93",
"lessThan": "6.12.112",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.18.17",
"lessThan": "6.18.55",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.19.7",
"lessThan": "6.20",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"arch/arm64/include/asm/io.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "7.0",
"status": "affected"
},
{
"version": "0",
"lessThan": "7.0",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.112",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.55",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.9",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/0b04af3d88bb7fc69b2d92457890608860e42365",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9b583795feb51f8d50203228d001760d1344ef01",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b17aa4955e3a694c663ebe99626e4c76ca4f7cfb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bb756b11ad63832ebee58caf9e8f9381eaecff9f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fddc90d4af4550af410f52d11bbf6b5f36443838",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}