In the Linux kernel, the following vulnerability has been resolved:
xsk: fix refcount underflow in error path
Fix a refcount underflow problem reported by syzbot that can happen
when a system is running out of memory. If xp_alloc_tx_descs() fails,
and it can only fail due to not having enough memory, then the error
path is triggered. In this error path, the refcount of the pool is
decremented as it has incremented before. However, the reference to
the pool in the socket was not nulled. This means that when the socket
is closed later, the socket teardown logic will think that there is a
pool attached to the socket and try to decrease the refcount again,
leading to a refcount underflow.
I chose this fix as it involved adding just a single line. Another
option would have been to move xp_get_pool() and the assignment of
xs->pool to after the if-statement and using xs_umem->pool instead of
xs->pool in the whole if-statement resulting in somewhat simpler code,
but this would have led to much more churn in the code base perhaps
making it harder to backport.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
No data.
No data.
References
History
Thu, 23 Oct 2025 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
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| Vendors & Products |
Linux
Linux linux Kernel |
Thu, 23 Oct 2025 00:15:00 +0000
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| References |
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| Metrics |
threat_severity
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cvssV3_1
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Wed, 22 Oct 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: xsk: fix refcount underflow in error path Fix a refcount underflow problem reported by syzbot that can happen when a system is running out of memory. If xp_alloc_tx_descs() fails, and it can only fail due to not having enough memory, then the error path is triggered. In this error path, the refcount of the pool is decremented as it has incremented before. However, the reference to the pool in the socket was not nulled. This means that when the socket is closed later, the socket teardown logic will think that there is a pool attached to the socket and try to decrease the refcount again, leading to a refcount underflow. I chose this fix as it involved adding just a single line. Another option would have been to move xp_get_pool() and the assignment of xs->pool to after the if-statement and using xs_umem->pool instead of xs->pool in the whole if-statement resulting in somewhat simpler code, but this would have led to much more churn in the code base perhaps making it harder to backport. | |
| Title | xsk: fix refcount underflow in error path | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2025-10-22T13:23:38.384Z
Updated: 2025-10-22T13:23:38.384Z
Reserved: 2025-10-22T13:21:37.345Z
Link: CVE-2023-53698
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2025-10-22T14:15:44.330
Modified: 2025-10-22T21:12:48.953
Link: CVE-2023-53698
Redhat