Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: mark set as dead when unbinding anonymous set with timeout
While the rhashtable set gc runs asynchronously, a race allows it to collect elements from anonymous sets with timeouts while it is being released from the commit path.
Mingi Cho originally reported this issue in a different path in 6.1.x with a pipapo set with low timeouts which is not possible upstream since 7395dfacfff6 (“netfilter: nf_tables: use timestamp to check for set element timeout”).
Fix this by setting on the dead flag for anonymous sets to skip async gc in this case.
According to 08e4c8c5919f (“netfilter: nf_tables: mark newset as dead on transaction abort”), Florian plans to accelerate abort path by releasing objects via workqueue, therefore, this sets on the dead flag for abort path too.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 6 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel @ 2.6.32 (+14 more)
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: mark set as dead when unbinding anonymous set with timeout
While the rhashtable set gc runs asynchronously, a race allows it to collect elements from anonymous sets with timeouts while it is being released from the commit path.
Mingi Cho originally reported this issue in a different path in 6.1.x with a pipapo set with low timeouts which is not possible upstream since 7395dfacfff6 (“netfilter: nf_tables: use timestamp to check for set element timeout”).
Fix this by setting on the dead flag for anonymous sets to skip async gc in this case.
According to 08e4c8c5919f (“netfilter: nf_tables: mark newset as dead on transaction abort”), Florian plans to accelerate abort path by releasing objects via workqueue, therefore, this sets on the dead flag for abort path too.