A race condition flaw was found in the Linux kernel's IP Last Anomaly (ILA) subsystem. This issue occurs when the `ila_output()` function, called from `lwtunnel_output()` in process context and under RCU read lock, could be interrupted by a softirq, leading to potential corruption of `dst_cache` data structures.
In the Linux kernel, the following vulnerability has been resolved:
ila: block BH in ila_output()
As explained in commit 1378817486d6 ("tipc: block BH
before using dst_cache"), net/core/dst_cache.c
helpers need to be called with BH disabled.
ila_output() is called from lwtunnel_output()
possibly from process context, and under rcu_read_lock().
We might be interrupted by a softirq, re-enter ila_output()
and corrupt dst_cache data structures.
Fix the race by using local_bh_disable().
Comment 1Mauro Matteo Cascella
2024-07-30 14:56:12 UTC
In the Linux kernel, the following vulnerability has been resolved: ila: block BH in ila_output() As explained in commit 1378817486d6 ("tipc: block BH before using dst_cache"), net/core/dst_cache.c helpers need to be called with BH disabled. ila_output() is called from lwtunnel_output() possibly from process context, and under rcu_read_lock(). We might be interrupted by a softirq, re-enter ila_output() and corrupt dst_cache data structures. Fix the race by using local_bh_disable().