NULL Pointer Dereference Affecting kernel-core package, versions *
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Test your applications- Snyk ID SNYK-RHEL9-KERNELCORE-7088135
- published 24 May 2024
- disclosed 21 May 2024
Introduced: 21 May 2024
CVE-2021-47223 Open this link in a new tabHow to fix?
There is no fixed version for RHEL:9 kernel-core.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-core package and not the kernel-core package as distributed by RHEL.
See How to fix? for RHEL:9 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: fix vlan tunnel dst null pointer dereference
This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.
References
- https://access.redhat.com/security/cve/CVE-2021-47223
- https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530
- https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f
- https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c
- https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d
- https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79
- https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7