fkie_cve-2023-54232
Vulnerability from fkie_nvd
Published
2025-12-30 13:16
Modified
2025-12-30 13:16
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
m68k: Only force 030 bus error if PC not in exception table
__get_kernel_nofault() does copy data in supervisor mode when
forcing a task backtrace log through /proc/sysrq_trigger.
This is expected cause a bus error exception on e.g. NULL
pointer dereferencing when logging a kernel task has no
workqueue associated. This bus error ought to be ignored.
Our 030 bus error handler is ill equipped to deal with this:
Whenever ssw indicates a kernel mode access on a data fault,
we don't even attempt to handle the fault and instead always
send a SEGV signal (or panic). As a result, the check
for exception handling at the fault PC (buried in
send_sig_fault() which gets called from do_page_fault()
eventually) is never used.
In contrast, both 040 and 060 access error handlers do not
care whether a fault happened on supervisor mode access,
and will call do_page_fault() on those, ultimately honoring
the exception table.
Add a check in bus_error030 to call do_page_fault() in case
we do have an entry for the fault PC in our exception table.
I had attempted a fix for this earlier in 2019 that did rely
on testing pagefault_disabled() (see link below) to achieve
the same thing, but this patch should be more generic.
Tested on 030 Atari Falcon.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nm68k: Only force 030 bus error if PC not in exception table\n\n__get_kernel_nofault() does copy data in supervisor mode when\nforcing a task backtrace log through /proc/sysrq_trigger.\nThis is expected cause a bus error exception on e.g. NULL\npointer dereferencing when logging a kernel task has no\nworkqueue associated. This bus error ought to be ignored.\n\nOur 030 bus error handler is ill equipped to deal with this:\n\nWhenever ssw indicates a kernel mode access on a data fault,\nwe don\u0027t even attempt to handle the fault and instead always\nsend a SEGV signal (or panic). As a result, the check\nfor exception handling at the fault PC (buried in\nsend_sig_fault() which gets called from do_page_fault()\neventually) is never used.\n\nIn contrast, both 040 and 060 access error handlers do not\ncare whether a fault happened on supervisor mode access,\nand will call do_page_fault() on those, ultimately honoring\nthe exception table.\n\nAdd a check in bus_error030 to call do_page_fault() in case\nwe do have an entry for the fault PC in our exception table.\n\nI had attempted a fix for this earlier in 2019 that did rely\non testing pagefault_disabled() (see link below) to achieve\nthe same thing, but this patch should be more generic.\n\nTested on 030 Atari Falcon."
}
],
"id": "CVE-2023-54232",
"lastModified": "2025-12-30T13:16:11.623",
"metrics": {},
"published": "2025-12-30T13:16:11.623",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1a6059f5ed57f48edfe7159404ff7d538d9d405b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2100e374251a8fc00cce1916cfc50f3cb652cbe3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/54fa25ffab2b700df5abd58c136d64a912c53953"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/8bf8d5dade4c5e1d8a2386f29253ed28b5d87735"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/df1da53a7e98f0b2a0eb2241c154f148f2f2c1d8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e36a82bebbf7da814530d5a179bef9df5934b717"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ec15405b80fc15ffc87a23d01378ae061c1aba07"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f55cb52ec98b22125f5bda36391edb8894f7e8cf"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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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