In the Linux kernel, the following vulnerability has been resolved:
xfrm: Update ipcomp_scratches with NULL when freed
Currently if ipcomp_alloc_scratches() fails to allocate memory
ipcomp_scratches holds obsolete address. So when we try to free the
percpu scratches using ipcomp_free_scratches() it tries to vfree non
existent vm area. Described below:
static void * __percpu *ipcomp_alloc_scratches(void)
{
...
scratches = alloc_percpu(void *);
if (!scratches)
return NULL;
ipcomp_scratches does not know about this allocation failure.
Therefore holding the old obsolete address.
...
}
So when we free,
static void ipcomp_free_scratches(void)
{
...
scratches = ipcomp_scratches;
Assigning obsolete address from ipcomp_scratches
if (!scratches)
return;
for_each_possible_cpu(i)
vfree(*per_cpu_ptr(scratches, i));
Trying to free non existent page, causing warning: trying to vfree
existent vm area.
...
}
Fix this breakage by updating ipcomp_scrtches with NULL when scratches
is freed
xfrm: Update ipcomp_scratches with NULL when freed
Currently if ipcomp_alloc_scratches() fails to allocate memory
ipcomp_scratches holds obsolete address. So when we try to free the
percpu scratches using ipcomp_free_scratches() it tries to vfree non
existent vm area. Described below:
static void * __percpu *ipcomp_alloc_scratches(void)
{
...
scratches = alloc_percpu(void *);
if (!scratches)
return NULL;
ipcomp_scratches does not know about this allocation failure.
Therefore holding the old obsolete address.
...
}
So when we free,
static void ipcomp_free_scratches(void)
{
...
scratches = ipcomp_scratches;
Assigning obsolete address from ipcomp_scratches
if (!scratches)
return;
for_each_possible_cpu(i)
vfree(*per_cpu_ptr(scratches, i));
Trying to free non existent page, causing warning: trying to vfree
existent vm area.
...
}
Fix this breakage by updating ipcomp_scrtches with NULL when scratches
is freed
Metrics
Affected Vendors & Products
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Advisories
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Fixes
Solution
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Workaround
No workaround given by the vendor.
References
History
Thu, 23 Oct 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
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| References |
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| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 22 Oct 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: xfrm: Update ipcomp_scratches with NULL when freed Currently if ipcomp_alloc_scratches() fails to allocate memory ipcomp_scratches holds obsolete address. So when we try to free the percpu scratches using ipcomp_free_scratches() it tries to vfree non existent vm area. Described below: static void * __percpu *ipcomp_alloc_scratches(void) { ... scratches = alloc_percpu(void *); if (!scratches) return NULL; ipcomp_scratches does not know about this allocation failure. Therefore holding the old obsolete address. ... } So when we free, static void ipcomp_free_scratches(void) { ... scratches = ipcomp_scratches; Assigning obsolete address from ipcomp_scratches if (!scratches) return; for_each_possible_cpu(i) vfree(*per_cpu_ptr(scratches, i)); Trying to free non existent page, causing warning: trying to vfree existent vm area. ... } Fix this breakage by updating ipcomp_scrtches with NULL when scratches is freed | |
| Title | xfrm: Update ipcomp_scratches with NULL when freed | |
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-22T13:23:25.810Z
Reserved: 2025-10-22T13:20:23.760Z
Link: CVE-2022-50569
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2025-10-22T14:15:41.780
Modified: 2025-10-22T21:12:48.953
Link: CVE-2022-50569
Redhat
OpenCVE Enrichment
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