CVE-2023-53698

Technical 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 m

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References