CVE-2026-97942 (GCVE-0-2026-97942)
Vulnerability from cvelistv5
Published
2026-09-25 10:22
Modified
2026-10-19 09:11
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
x86/alternatives: Exclude text poking against change_page_attr()
From time to time, the following BUG can be observed
in the x86 alternatives patching code [0]:
> kernel BUG at arch/x86/kernel/alternative.c:2576!
> Oops: invalid opcode: 0000 [#1] SMP NOPTI
> CPU: 0 UID: 0 PID: 355 Comm: (udev-worker) Not tainted 7.1.3-1-default #1 PREEMPT(full) openSUSE Tumbleweed 8c1795b03ec64f997e57a8ad38b1161e3b98da64
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022
> RIP: 0010:__text_poke+0x2aa/0x450
> Call Trace:
> <TASK>
> smp_text_poke_batch_finish+0x2a7/0x320
> __static_call_transform+0xb7/0x220
> arch_static_call_transform+0x5b/0xb0
> __static_call_init+0xe9/0x270
> static_call_module_notify+0x11f/0x150
> notifier_call_chain+0x61/0xe0
> blocking_notifier_call_chain_robust+0x63/0xc0
> load_module+0x1c92/0x20c0
> init_module_from_file+0xd8/0x140
> idempotent_init_module+0x100/0x2f0
> __x64_sys_finit_module+0x71/0xe0
> do_syscall_64+0xe1/0x610
> entry_SYSCALL_64_after_hwframe+0x76/0x7e
which matches the following BUG_ON() in alternative.c:
/*
* If something went wrong, crash and burn since recovery paths are not
* implemented.
*/
BUG_ON(!pages[0] || (cross_page_boundary && !pages[1]));
This can happen if vmalloc_to_page() fails, for any reason. Such can happen
if text poking races with CPA, which can possibly result in the collapsing
of page tables (or breaking of PMD hugepages). It is not a problem for most
users of vmalloc_to_page() (they solely own the vmalloc'd range) but, when
CONFIG_ARCH_HAS_EXECMEM_ROX=y, various modules own a single execmem vmalloc
range, and can call set_memory_*() in parallel on it. This can happen to
race against __text_poke and cause havoc in vmalloc_to_page().
Fix it by excluding against CPA using the init_mm mmap read lock.
[ dhansen: Fix up SoB ordering. The actual code flow here was:
Pedro=>Lorenzo=>Mike=>Me which is reflected in the SoB chain
now. I *believe* Mike simply picked up Lorenzo's update to
Pedro's post from the Link ]
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/x86/kernel/alternative.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "281e6f536f2f3f95d91938c5bd7ba9bcb4c1049d",
"status": "affected",
"version": "64f6a4e10c05ed527f0f24b7954964255e0d3535",
"versionType": "git"
},
{
"lessThan": "89c60435b90d32ab5e3a39da3ae73d463d07debe",
"status": "affected",
"version": "64f6a4e10c05ed527f0f24b7954964255e0d3535",
"versionType": "git"
},
{
"lessThan": "1587d3394e254639cc36516256031334095e6ef3",
"status": "affected",
"version": "64f6a4e10c05ed527f0f24b7954964255e0d3535",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/x86/kernel/alternative.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"lessThan": "6.15",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.53",
"versionStartIncluding": "6.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.7",
"versionStartIncluding": "6.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "6.15",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/alternatives: Exclude text poking against change_page_attr()\n\nFrom time to time, the following BUG can be observed\nin the x86 alternatives patching code [0]:\n\n \u003e kernel BUG at arch/x86/kernel/alternative.c:2576!\n \u003e Oops: invalid opcode: 0000 [#1] SMP NOPTI\n \u003e CPU: 0 UID: 0 PID: 355 Comm: (udev-worker) Not tainted 7.1.3-1-default #1 PREEMPT(full) openSUSE Tumbleweed 8c1795b03ec64f997e57a8ad38b1161e3b98da64\n \u003e Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022\n \u003e RIP: 0010:__text_poke+0x2aa/0x450\n \u003e Call Trace:\n \u003e \u003cTASK\u003e\n \u003e smp_text_poke_batch_finish+0x2a7/0x320\n \u003e __static_call_transform+0xb7/0x220\n \u003e arch_static_call_transform+0x5b/0xb0\n \u003e __static_call_init+0xe9/0x270\n \u003e static_call_module_notify+0x11f/0x150\n \u003e notifier_call_chain+0x61/0xe0\n \u003e blocking_notifier_call_chain_robust+0x63/0xc0\n \u003e load_module+0x1c92/0x20c0\n \u003e init_module_from_file+0xd8/0x140\n \u003e idempotent_init_module+0x100/0x2f0\n \u003e __x64_sys_finit_module+0x71/0xe0\n \u003e do_syscall_64+0xe1/0x610\n \u003e entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nwhich matches the following BUG_ON() in alternative.c:\n\n\t/*\n\t * If something went wrong, crash and burn since recovery paths are not\n\t * implemented.\n\t */\n\tBUG_ON(!pages[0] || (cross_page_boundary \u0026\u0026 !pages[1]));\n\nThis can happen if vmalloc_to_page() fails, for any reason. Such can happen\nif text poking races with CPA, which can possibly result in the collapsing\nof page tables (or breaking of PMD hugepages). It is not a problem for most\nusers of vmalloc_to_page() (they solely own the vmalloc\u0027d range) but, when\nCONFIG_ARCH_HAS_EXECMEM_ROX=y, various modules own a single execmem vmalloc\nrange, and can call set_memory_*() in parallel on it. This can happen to\nrace against __text_poke and cause havoc in vmalloc_to_page().\n\nFix it by excluding against CPA using the init_mm mmap read lock.\n\n[ dhansen: Fix up SoB ordering. The actual code flow here was:\n\t Pedro=\u003eLorenzo=\u003eMike=\u003eMe which is reflected in the SoB chain\n\t now. I *believe* Mike simply picked up Lorenzo\u0027s update to\n\t Pedro\u0027s post from the Link ]"
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T09:11:08.757Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/281e6f536f2f3f95d91938c5bd7ba9bcb4c1049d"
},
{
"url": "https://git.kernel.org/stable/c/89c60435b90d32ab5e3a39da3ae73d463d07debe"
},
{
"url": "https://git.kernel.org/stable/c/1587d3394e254639cc36516256031334095e6ef3"
}
],
"title": "x86/alternatives: Exclude text poking against change_page_attr()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-97942",
"datePublished": "2026-09-25T10:22:54.188Z",
"dateReserved": "2026-09-25T10:18:58.204Z",
"dateUpdated": "2026-10-19T09:11:08.757Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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