CVE-2024-26740: net/sched: act_mirred: use the backlog for mirred ingress
In the Linux kernel, the following vulnerability has been resolved:
net/sched: actmirred: use the backlog for mirred ingress
The Linux kernel CVE team has assigned CVE-2024-26740 to this issue.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024040300-CVE-2024-26740-4d6f@gregkh/T
Other sources
In the Linux kernel, the following vulnerability has been resolved:
net/sched: actmirred: use the backlog for mirred ingress
The test Davide added in commit ca22da2fbd69 ("actmirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcpv4rcv -> tcpv4rcv deadlock reported by lockdep.
The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls.
In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue.
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-26740?
CVE-2024-26740 has been classified as a moderate severity vulnerability in the Linux kernel.
How do I fix CVE-2024-26740?
To mitigate CVE-2024-26740, upgrade the Linux kernel to version 6.6.19, 6.7.7, or 6.8.
Which versions of the Linux kernel are affected by CVE-2024-26740?
CVE-2024-26740 affects Linux kernel versions from 4.10 up to, but not including, 6.6.19 and also impacts pre-release versions of 6.8.
Is there a workaround for CVE-2024-26740?
Currently, there is no confirmed workaround for CVE-2024-26740 aside from updating the kernel.
What impact does CVE-2024-26740 have on system security?
CVE-2024-26740 could potentially allow for undesirable behavior in network traffic scheduling, affecting overall system security and performance.