Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
igb: revert rtnl_lock() that causes deadlock
The commit 6faee3d4ee8b (“igb: Add lock to avoid data race”) adds rtnl_lock to eliminate a false data race shown below
(FREE from device detaching) | (USE from netdev core) igb_remove | igb_ndo_get_vf_config igb_disable_sriov | vf >= adapter->vfs_allocated_count? kfree(adapter->vf_data) | adapter->vfs_allocated_count = 0 | | memcpy(… adapter->vf_data[vf]
The above race will never happen and the extra rtnl_lock causes deadlock below
[ 141.420169]
Since the igb_disable_sriov() will call pci_disable_sriov() before releasing any resources, the netdev core will synchronize the cleanup to avoid any races. This patch removes the useless rtnl_(un)lock to guarantee correctness.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 4.18.0 (+4 more)
In the Linux kernel, the following vulnerability has been resolved:
igb: revert rtnl_lock() that causes deadlock
The commit 6faee3d4ee8b (“igb: Add lock to avoid data race”) adds rtnl_lock to eliminate a false data race shown below
(FREE from device detaching) | (USE from netdev core) igb_remove | igb_ndo_get_vf_config igb_disable_sriov | vf >= adapter->vfs_allocated_count? kfree(adapter->vf_data) | adapter->vfs_allocated_count = 0 | | memcpy(… adapter->vf_data[vf]
The above race will never happen and the extra rtnl_lock causes deadlock below
[ 141.420169]
Since the igb_disable_sriov() will call pci_disable_sriov() before releasing any resources, the netdev core will synchronize the cleanup to avoid any races. This patch removes the useless rtnl_(un)lock to guarantee correctness.