ghsa-r3v9-vm52-w2px
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT
lppaca_shared_proc() takes a pointer to the lppaca which is typically accessed through get_lppaca(). With DEBUG_PREEMPT enabled, this leads to checking if preemption is enabled, for example:
BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693 caller is lparcfg_data+0x408/0x19a0 CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2 Call Trace: dump_stack_lvl+0x154/0x200 (unreliable) check_preemption_disabled+0x214/0x220 lparcfg_data+0x408/0x19a0 ...
This isn't actually a problem however, as it does not matter which lppaca is accessed, the shared proc state will be the same. vcpudispatch_stats_procfs_init() already works around this by disabling preemption, but the lparcfg code does not, erroring any time /proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled.
Instead of disabling preemption on the caller side, rework lppaca_shared_proc() to not take a pointer and instead directly access the lppaca, bypassing any potential preemption checks.
[mpe: Rework to avoid needing a definition in paca.h and lppaca.h]
{
"affected": [],
"aliases": [
"CVE-2023-54267"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-30T13:16:15Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT\n\nlppaca_shared_proc() takes a pointer to the lppaca which is typically\naccessed through get_lppaca(). With DEBUG_PREEMPT enabled, this leads\nto checking if preemption is enabled, for example:\n\n BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693\n caller is lparcfg_data+0x408/0x19a0\n CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2\n Call Trace:\n dump_stack_lvl+0x154/0x200 (unreliable)\n check_preemption_disabled+0x214/0x220\n lparcfg_data+0x408/0x19a0\n ...\n\nThis isn\u0027t actually a problem however, as it does not matter which\nlppaca is accessed, the shared proc state will be the same.\nvcpudispatch_stats_procfs_init() already works around this by disabling\npreemption, but the lparcfg code does not, erroring any time\n/proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled.\n\nInstead of disabling preemption on the caller side, rework\nlppaca_shared_proc() to not take a pointer and instead directly access\nthe lppaca, bypassing any potential preemption checks.\n\n[mpe: Rework to avoid needing a definition in paca.h and lppaca.h]",
"id": "GHSA-r3v9-vm52-w2px",
"modified": "2025-12-30T15:30:34Z",
"published": "2025-12-30T15:30:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-54267"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2935443dc9c28499223d8c881474259e4b998f2a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3c5e8e666794d7dde6d14ea846c6c04f2bb34900"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4c8568cf4c45b415854195c8832b557cdefba57a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/953c54dfdc5d3eb7243ed902b50acb5ea1db4355"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eac030b22ea12cdfcbb2e941c21c03964403c63f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f45ee5c074013a0fbfce77a5af5efddb01f5d4f4"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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