GHSA-PGWW-XQQJ-6XV5
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-15 15:30In the Linux kernel, the following vulnerability has been resolved:
uprobes: Fix NULL pointer dereference in hprobe_expire()
Forking a task that has a pending uretprobe can oops the kernel with a NULL pointer dereference in the clone() path:
BUG: kernel NULL pointer dereference, address: 0000000000000018 Oops: 0002 [#1] SMP NOPTI RIP: 0010:hprobe_expire CR2: 0000000000000018 Call Trace: uprobe_copy_process copy_process kernel_clone __x64_sys_clone do_syscall_64 entry_SYSCALL_64_after_hwframe
This was found on real hosts on Meta fleet.
I've got the impression that this is what is happening:
CPU 1 CPU 2 (traced task) ----- ------------------- hit uprobe, prepare_uretprobe(): hprobe LEASED, refcount >= 1 uprobe_unregister() put_uprobe(): refcount -> 0 fork() -> dup_utask() hprobe_expire(hprobe, true) try_get_uprobe() -> NULL get_uprobe(NULL) <-- Oops
Only take the extra reference when the uprobe is non-NULL; a NULL means it is gone and is the correct value to return.
{
"affected": [],
"aliases": [
"CVE-2026-74477"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:17:52Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nuprobes: Fix NULL pointer dereference in hprobe_expire()\n\nForking a task that has a pending uretprobe can oops the kernel with a\nNULL pointer dereference in the clone() path:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n Oops: 0002 [#1] SMP NOPTI\n RIP: 0010:hprobe_expire\n CR2: 0000000000000018\n Call Trace:\n uprobe_copy_process\n copy_process\n kernel_clone\n __x64_sys_clone\n do_syscall_64\n entry_SYSCALL_64_after_hwframe\n\nThis was found on real hosts on Meta fleet.\n\nI\u0027ve got the impression that this is what is happening:\n\n CPU 1 CPU 2 (traced task)\n ----- -------------------\n hit uprobe, prepare_uretprobe():\n hprobe LEASED, refcount \u003e= 1\n uprobe_unregister()\n put_uprobe(): refcount -\u003e 0\n fork() -\u003e dup_utask()\n hprobe_expire(hprobe, true)\n try_get_uprobe() -\u003e NULL\n get_uprobe(NULL) \u003c-- Oops\n\nOnly take the extra reference when the uprobe is non-NULL; a NULL means\nit is gone and is the correct value to return.",
"id": "GHSA-pgww-xqqj-6xv5",
"modified": "2026-08-15T15:30:33Z",
"published": "2026-08-15T15:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74477"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/06c275a6c0a953ef1d763d11a6891fcc69ae2ac0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3bd35a5e272a1b7a3fb43acad9bdc599281b13fa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cc679d7a6303e84d769f2afcde1fc51c51f127cd"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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